Fraser Fir IPM

How Do You Know When Scale Control Is Working?

2012-01-09T15:16:00.000-05:00

It's not always easy knowing if elongate hemlock scale (EHS) controls are working. On Friday, Meghan Baker and I helped a grower evaluate some Safari and Talstar treatments he'd made in July and August. I collected shoots to look at under the microscope to determine if the scales were alive or dead. That is the only way to know for sure what kind of control you've gotten. Unfortunately, it takes a lot of work, and few people have access to a microscope.

So how can you tell how well your scale controls are working? Here are some things you can look for several months after treatment. Remember, you won't be able to tell within a few weeks. In fact, all of our treatments can take several months to work.

It's a lot harder to find the scales after treatment. The grower we were working with really knews his fields. He went to several trees that he knew had a lot of scale on them, and had a hard timing finding any. That's a good sign that controls are working. One suggestion is to tag trees with lots of scale prior to treating so you know where to go back to!
There isn't white cotton from the males scales. We were looking on a beautiful day in January. Though the weather was warm, you wouldn't expect to see the white cotton from the male scales yet. That's more of a summer thing. But, if you treated in the spring and were scouting in the summer and didn't see white on the trees, that's a good indication that there has been some control. But, I've seen fields where the control was only marginal where the male production was definitely suppressed. So in my opinion, this is not the best indicator of control.
There aren't crawlers. Crawlers and immature scales are yellow. If you scout several months after application and don't see yellow individuals, then it's a good indication that the treatments have worked.
There aren't scales on the newest growth. If you treated last year or in the spring, and you don't see any scales forming on the new growth in June or July, that's a really good indication that controls are working . The scales will remain on older growth even if they are dead. Of course some do fall off, but some will remain. So always look at the newest growth to see if there are any scales forming. This is one of the best indicators of control, but you have to wait for it!
The scales look dried up and are falling off. When controls are really good, there is a different appearance to the scales. The males all look dried up, and the females do too. You don't see any yellow immatures. And you can sometimes see on the needle that there used to be a scale present, and there isn't any more. This is a little tricky, because the females scales are brown, and might appear dead. But if you've seen enough treatments, you can develop an eye for what is really dead and what isn't. It helps to train your eye by looking at some of these samples under the microscope.

Looking under the microscope. When I evaluate scale control, I pull 2 or 3 needles off of 6 or 7 different shoots. I try to get some older and some younger needles. I take anything sharp like a pin, and gently prick the very top of the scale. The goal is not to stab the scale and the needle, but to pry off the top of the scales's outer covering to find if the scale is still alive inside. Below are some photos of what to look for.

Obviously, this scale is still very active.

A crawler or any small yellow scales indicates controls didn't work.

Is this female alive or dead?

It is dead because it is empty and dried up inside.

This female is alive, and there are eggs present.

The same photo with everything labeled.

Scales on new growth in June show that treatments didn't work.

The Safari and Talstar treatments made in August gave 99% control. What does that mean? That means that out of 100 or more scales that I examined, only one female was still alive. In actuality, the control is probably even greater because there weren't as many scales as there were prior to treatment.

The grower had some other Safari + Talstar treatments where he used the low rate of Safari (4 ounces per 100 gallons vs. 8 ounces/100 gallons). These were giving 94% control. That means I found 2 or 3 live scales. So should he treat again?

I think I would wait until June to see if scales were showing up on the new growth. If they aren't, I would wait until 2013 to treat again. If they are, he would still have a couple of months to make a treatment in 2012.

This grower also had another scale -- pine needle scale. This scale is much easier to control, and all his treatments worked against it. In the photo below, note some of the scales have holes in the middle, indicating that parasitic wasps have attacked them.

These are all pine needle scale and not elongate hemlock scale.

Assessing EHS control isn't easy. If you need help, contact your local county extension agent and I'll be glad to come out and see. Being patient and waiting until June is probably the easiest way to determine control results.

Safari Labeled for Christmas Trees

2012-01-05T15:19:00.000-05:00

Safari is now clearly labeled for use on Christmas trees. The following links have information about this material:

To date, excellent control of both balsam woolly adelgid and elongate hemlock scale have been obtained through foliar sprays of Safari at 8 ounces/100 gallons using a high pressure sprayer. I'm continuing to look at other methods of application.

Parasitic Wasps on Scale Infested Trees

2012-01-05T15:12:00.000-05:00

This photo depicts Frasers set up to see how likely elongate hemlock scale crawlers will come off of cut trees. The yellow sticky cards were used to trap the crawlers. But something more interesting was found. Wasps!

These are predatory wasps, probably Encarsia citrina though I didn't have them positively identified. They are very small. The following photo has both a wasp (on the right) and a crawler (bottom left) on it. You can see the wasp is only a bit larger than the crawler.

The wasps lay an egg in a scale and it develops inside. When the wasp emerges, it leaves a hole in an otherwise empty scale casing. You can see these sometimes when looking at scales on trees.

I put a photo of a wasp that hadn't emerged yet from inside of a scale on my October 6, 2011 post "Last Treatments." In that post, I made the comment that when you don't add Talstar or Asana to Safari, you see a lot more parasitized scales.

Interestingly, I only found these wasps on cards put in the two untreated trees. The tree that had been treated in the fall had no wasps in it. That made me curious to see how readily wasps are found on trees following different treatments. I plan on setting up some branches inside a warm location over the next few weeks to see how many wasps appear on sticky cards. Perhaps this can shed some light on how we can control scales without creating conditions for a quick rebound by killing off all of our natural enemies.

These wasps are very small. You would never see them flying around in your trees. But they are giving you free pest control. That's why its so important to only use an insecticide when you really have to.

Another view of one of the wasps.

How Well Do Scale Infested Trees Hold Their Needles?

2011-11-08T10:12:00.001-05:00

If a tree is infested with scales, will it cause the needles to shed prematurely? Last year I looked quite a bit at this issue, but without a lot of success. Here are links to the previous posts in case you are interested in following this story: 1. Setting up the study; 2. The results. The big problem with last year's study was that the room where I kept the shoots got way too hot, and there were many branches where the needles shattered. This isn't how Fraser fir normally behaves when cut.

So this year I'm trying again. Yesterday Jeff Vance helped me collect some scale infested branches. I will be comparing needle shed on these to branches from uninfested trees in the same field. We also collected some heavily infested branches from a second field just to see if they fared worse.

I will be monitoring needle shed on this year and last year's growth. Each branch is in its own water container, with the 3-year-old wood in the water. The study is set up at my house so I can keep an eye on them better. I noticed this morning that they are already taking up water!

Small studies like this allow us to look at this issue with a great deal of detail under controlled conditions. But I'm also very interested in hearing your observations. Are you finding that needles shed worse in scale infested trees? If you have any observations, please let me know. Some questions I would like to ask are these:

Were the trees heavily or lightly infested?
Are you selling trees in northern or southern markets?
Do you see a difference in performance between foliage in wreaths and trees?

Send me an email at: jill_sidebottom@ncsu.edu

As always, let's learn together as we try to live with this new pest.

White Pine Problems

2011-10-31T09:54:00.000-04:00

People still have white pines! And this fall, these have been hammered in the northern mountains by what we think is a needle cast.

People started seeing yellowing and browning needles a few weeks ago. Damage typically occurred in the upper portion of the plant but occasionally was all over. Many growers commented that they had been in the field just a few weeks prior to this and saw no problems, even tagging some trees, only to come back later to find major needle loss.

When you look closely, not every needle in a fascicle is affected. Sometimes there are bands of green and yellow tissue on the needles. Many growers also found that only the sheared white pine was affected. We only found one site where there were some unsheared white pines that also had the same symptoms.

When this occurred in 2007, the problem was diagnosed as Bifusella linearus, a needle cast found on white pines. We have sent samples off to look at a positive identification this year. However, it is often hard to diagnose needle casts. There are several fungi associated with white pine needles. And there is also confusion between needle casts and ozone injury on white pine.

Ozone damages plants by making the stomates sluggish. It is typically the fast growing trees and weeds that are affected most by ozone. The USDA website (click here for site) lists the following plants as good indicators of ozone damage along with the damage seen:

Blackberry, secondary canes (Rabus spp.): Red to purple stipple.
Black cherry (Prunus serotina): Red to purple stipple, may drop the injured leaves early.
Common milkweed (Asclepias syriaca): Purple to black stipple, leaves may be chlorotic (yellow).
Yellow-poplar (Liriodendron tulipifera): Brown stipple, may drop the injured leaves early.
White ash (Fraxinus americana): Red to brown stipple. Similar injury is also found on green ash

So if you suspect ozone, look at these indicator plants nearby to see if there is also damage. White pines were taken off the indicator list in 1995. If these are not showing symptoms, it is most likely a needle cast.

This is also some question if fertility is playing a role. This time of year calcium deficiency is showing up in Fraser firs and white pines. If you are having extensive problems with needle loss, it might be a good idea to take some soil samples and plant tissue samples to further diagnose the problem.

No matter what is causing this damage, there is probably little a grower can do. One of the main reasons is that the profit margin is so low on white pines that it makes any fungicide treatment unattractive. However, when we get a positive diagnosis, I'll pass along treatment options.

Of course the main question is if the damage will continue to get worse this fall. In falls past it did not, so hopefully what we're seeing right now is the worst of it, and undamaged individuals will remain looking good. The following are some photos I took on Friday.

Banding on the needles

Not every tree is affected and not all the same way.

On this plant, damage only occurs in the upper portion of the plant.

Another shot of banding.

This tree was affected overall.

Last Treatments

2011-10-06T07:15:00.001-04:00

I haven't posted anything on my blog for quite awhile. Not because I haven't been busy, I just wanted to get all my results together before doing so. I've been evaluating multiple spring applications of Safari and other materials for elongate hemlock scale control. Since I feel like I should wait 4 months before making evaluations, it has taken quite awhile. I should finish with the spring applied stuff this week, and then I'll compile the results. Maybe I'll even have them by Friday!

However, I did want to let everyone know that I put out my last EHS treatment yesterday. Well, Jeff Vance did actually. We treated trees with Sniper, the new bifenthrin product and a dinotefuran product (active ingredient of Safari). We mixed the products to give the same as 10 oz Talstar per 100 gallons and 8 oz of Safari. Two rows of trees Jeff treated like a woolly spray, and two rows like a twig aphid spray. We used about 1/2 the water the second go round. Those results, I won't have until February!

If this fall treatment controls scales, it would fit in very nicely with production of Fraser fir. With it you would be controlling woollies, twigs, scales, spiders, and Cinaras in go-to-market trees. You have lovely fall weather which is usually drier and cooler (it seemed rather hot to me in that spray suit though!) to do it in. AND, you wouldn't be affecting the predators at all. So that means you won't be creating problems with rust mites come spring, or a resurgence of scales the following year.

What predators are most important for the control of scales? Lady bugs will feed on them, especially the twice-stabbed lady beetle, but also smaller ones. We've also seen lacewing larvae feeding on scales. There are also parasitic wasps that develop inside the scale itself.

I will share one observation I've been making. When people are using just Safari in the spring or summer and not adding a synthetic pyrethroid (esfenvalerate (Asana) or bifenthrin (Talstar, Wisdom, Sniper)) you see a lot more parasitized scales.

In fact, one day I poked open a scale that had a wasp still inside the scale, and when I gently teased it out, it moved it's head around.

Bugs are so cool!

Predatory wasp developing inside female EHS.

This is usually all you see with a scale that has been parasitized. An exit hole!

Clingman's Dome and Wild Trees

2011-08-19T12:49:00.000-04:00

Ghostly skeletons of Frasers emerge in the fog on Clingman's Dome as young trees grow around.

I had the opportunity to visit Clingman's Dome in the Great Smoky Mountains National Park this week. It had been years since I'd been there. The last time I visited, it was with Kristine Johnson with the National Park when they were treating for balsam woolly adelgid (BWA). At that time, they used insecticidal soap in the summer to treat the trees around the parking lot, walkway and tower on top of the mountain. To my knowledge, these treatments have stopped.

Treating on Clingman's Dome for BWA in early 90s with insecticidal soap.
The soap was mixed in the white vat and a powerful pump was used to spray the product on the trees.

They would spray the trees with fire hoses using many volunteers.
Hard hats were required as the pressure spray might bring down limbs.

Insecticidal soap isn't the best treatment in the summer as there are eggs present, and many survive the treatment. With soap there are no residuals to kill the crawlers that emerge from the eggs, and it takes about a month for the eggs to hatch. However in the winter when eggs aren't present the road to the top is closed. Also I'm sure there was quite a bit of damage to the natural habitat just from all the spray activity.

Today it looked different than I remembered. There weren't many tall Frasers, but there was quite a bit of healthy regrowth. Still, it looked like there was a lot more open ground than when I was there last.

Shot from the visitor center parking lot at Clingman's Dome on 8/17/11.

We were there on a very foggy day as can be seen in this video. It is living in the fog that makes Fraser fir such a great Christmas tree. Frasers are very sensitive to dry air since they live in the clouds. They quickly shut their stomates which keep them from drying out.

The following are photographs from the visit.

The tower today.

Lots of wildflowers are growing in areas left bare from dead trees.

The young trees coming on look good, but they are somewhat resistant to BWA as they produce juvabione.
This is an insect growth regulator that keeps the insect from becoming mature.

Larger trees stop producing juvabione and become infested.
Each white spot covers an adult female which will lay a dozen eggs or so.

The tree in the previous picture is on the left. It has no top left. Other trees around it still do.
The loss of apical dominance is a symptom of BWA infestation.

Even with the dying trees, Clingman's Dome is a popular destination.
The steep walk to the tower and all the fog doesn't keep people from going to the top,
even if you have to stop to catch your breath along the way!

Cinara Aphids

2011-08-15T12:30:00.000-04:00

Cinara aphids are some of the largest aphids in the world.

I can't believe I've never had a post just on Cinara aphids! Now is the time the people are starting to think about them. I talked to 2 or 3 growers last week who asked the same question -- is it too early to treat for Cinara aphids and keep them out of my go-to-market trees? Sadly, there isn't an easy answer to that question.

I talked with only one grower so far that has seen Cinaras in his trees this fall. Mostly they aren't seen until they show up in someone's home. Many people now treat preventatively for the pests, using Talstar or Wisdom which are both bifenthrin products in late September or October. But now is still a good time to treat for elongate hemlock scales with Asana and Dimethoate. And if you know Cinaras are in your trees now, should you wait until October or go ahead and spray?

The question that we don't have an answer to is how quickly do these aphids move into new areas. Some individual aphids have wings, allowing them to fly into trees. However, they aren't very good fliers. Basically all they can do is get up in the air and allow the wind to carry them places. They don't direct their flight like a fly or a bee.

A winged individual.

Once they are in suitable locations, they lay live young, so their numbers can quickly rebound. However, most of the pesticides that people are using will last several weeks on trees. Therefore it would seem unlikely for Cinaras to move into trees treated in mid-August by mid-November, though the possibility exists. It would depend on each grower's concerns about the pest and how they are applying their materials. Spraying with a mistblower may allow quicker build-up again, while using a high pressure sprayer and getting good coverage will more likely take care of the problem from now until harvest.

One reason to go ahead and treat now is that most of the aphids are still higher up in the tree where they are more easily controlled. As it gets colder, it seems that the aphids move to the lower branches, making it harder to get a chemical to them, and certainly with a mistblower.

When Cinara aphids are on the trunk of the tree, it is harder for a mistblower to reach them.

No matter if you treat now or wait, there is a new product on the market for pest control in Christmas trees including Cinara aphids. Sniper, which is a 25% bifenthrin product, is now labeled for Christmas trees. It should be cheaper than Talstar. Click here for the label and msds sheets.

And what about the Cinara eggs? I've only seen them once in all my nearly 23 years working in the industry!

Cinara aphid eggs found in Ashe County about 10 years ago.

In the literature, different Cinara species only lay eggs infrequently. So basically, growers are fighting a live aphid that can reproduce very quickly. And if anyone does see these eggs, please give me a call. I'd love to see them again!

Whenever you are in your trees this fall, be sure to look closer if wasps or yellow jackets are interested in your trees. It could well be Cinara aphids. This typically happens during warm, dry days in the fall when the wasps are especially active. Beat the foliage of a few of these trees to see if aphids fall out.

Wasps are attracted to the sweet honey dew that aphids secrete.

You sometimes find Cinaras when you are beating the foliage to find other pests.

Also be sure that the folks tagging and harvesting your trees can recognize the aphids and their characteristic purple smear.

If you do end up with problems with Cinara aphids on harvested trees, remember these links for information. If you have a retail-lot, you might want to make a few printed copies of the last link in case of problems.

I am always happy to speak with your customers about this pest problem should the need arise.

Organic Project Update

2011-08-11T14:26:00.000-04:00

Last month I visited the Extension Organic demonstration and once again rated the trees based on their terminal growth and overall appearance. I made a similar ratings last year and posted them on my blog on August 24, 2010.

I rated the tree appearance the same way I did last year. Trees were given a rating of "1" if they were barely growing. A "2" rating was given to a tree that was growing better, but still had poor color and bud set. A "3" rating was given to a tree that was growing acceptably. A "4" rating was given to an exception tree both in color, bud set, needle length and fullness. Of course these ratings were completely subjective and sometimes I had trouble deciding between a "2" and a "3" or a "3" and a "4."

Here are the results:

The results were very similar to last year. Some trees looked worse than they did last year and some looked better. Overall the organic trees appeared to have improved a bit, but there were still many more trees growing poorly than the "late" organic trees. (Remember that the "late" organic trees will switch to complete organic practices next year, but so far have been treated conventionally with Round-up and synthetic fertilizers).

But as they say, pictures are worth a thousand words. Here are two shots in July of the organic and late organic trees:

Organic trees -- there are a few good trees but not many.

These trees have been grown conventionally and will switch to organic production next year.

It will be interesting to see switching to organic fertilizers will affect the "late" organic trees. I'll let you know same time next year!

Movento and Rosette Bud Mites

2011-07-18T21:38:00.000-04:00

Field where Movento applied in Avery County.

On Friday, Jerry Moody and Doug Hundley with Avery County Extension helped me evaluate rosette bud mite control in a grower’s field. I reported on this study on June 15. Then I just pulled some shoots at random to see if I could find any rosette bud mites. But now you can clearly see which buds look like rosette buds and if there are living mites present inside the bud.

Currently our best control has been to apply Dimethoate when the new growth is out 4-6 inches. A few growers have also tried Mavrik during that time frame with some results. But these have always been with a high pressure application.

Some growers have gotten good control with Dimethoate using a mistblower if they use a lot of water per acre (50+ gallons) and/or treat twice during that June treatment window. We were interested in trying the new systemic material, Movento with a mistblower.

Don’t confuse Movento and Safari. They are two different chemicals from two different chemical families. The active ingredient in Movento is spirotetramat. It is labeled at 5 to 10 ounces per acre.

The following two statements are from the label:

“Movento is a suspension concentration formulation and is active primarily by ingestion against immature target pest life stages. In addition, fertility of adult female target pests, such as aphids and whiteflies, may be reduced.” This means that the pest has to feed on the plant having Movento in it to work. It also means that it will take some time for the product to work, as it is affecting pest development and fertility.

“Movento must be tank-mixed with a spray adjuvant/additive having spreading and penetrating properties to maximize leaf uptake and systemicity of the active ingredient within treat plant.” We have successfully used the adjuvant Liberate (which also makes droplet size larger, making it a good choice for mistblowers) and a 1% horticultural oil solution.

When Jerry and I tried this product last year for twig aphid control, we saw one tree that had rosette buds that didn’t have any following treatment. Since we were treating in mid April, it appeared that the systemic action of the Movento was getting into the tree and preventing the rosette bud mites from developing. It had time to work throughout May and into June to control the mites.

This spring, we got Clay Cutherbertson in Avery County to apply the product with his mistblower. He treated in April using 10 ounces per acre and about 70 gallons of water per acre. Friday we went through those blocks, and found very few trees that looked like they had rosette buds on 2011 growth, and those few buds had no live mites in them. (Actually I did see one live mite under the microscope, but it was in a fully formed, normal bud and could no longer create a deformed rosette bud).

This is just one study in one field, but it looks very promising. A spring application of Movento with a mistblower may well control two of our most difficult to control pests – balsam woolly adelgid and rosette bud mites. Twig aphid control with Movento is only fair, but in fields that had twig aphid control from the fall, or by adding another material such as Talstar which works well against twig aphid (that’s why Clay did), you can control multiple pests in the spring.

Like most studies, this little test creates some more questions. Does Movento have activity against rust mites which are quite similar to rosette bud mites? Can you treat with Movento any time of year and control the mites inside the bud? These are some things we’ll be looking at in the future. Keep checking back to the blog for more information about Movento and other chemical controls.

New Pesticide Safety Training Materials

2011-07-15T14:04:00.000-04:00

The folks at North Carolina State University have put together a training packet for Christmas tree growers to share with their Latino farmworkers. Called the Pesticides and Farmworker Health Toolkits (click to see information at NCSU), the programs are specific to the different commodities grown in North Carolina. The standard kit includes:

--Introductory DVD for trainers,
--Flip-chart in Spanish (with discussion guides for trainers and colorful visuals illustrating the trainer’s message for the audience),
--One-page illustrated handouts in Spanish,
--Interactive materials, including jug and labels and symptom charade cards,
--Totebag.

The one for Christmas trees is hot off the presses. We used it at a Latino farmworker safety training on July 13 in Foscoe. Held at Hawk Mountain Tree Farms, the training included several stations, one of which was pesticide safety. I helped Jim Hamilton, Watauga County Director and Charles Clark and Travis Snodgrass, both with NCDA conduct the training.

Jim Hamilton explaining about chemical resistant footwear.

Charles Clark and Jim Hamilton use the flipchart to teach workers about pesticide toxicity.

In these training materials, the toxicity of different materials is related to a stop light. Very toxic materials having a "Danger" signal word have a red light, materials that have a "Warning" signal word show a yellow light, and the least toxic materials with a "Caution" signal word have a green light. The handout in Spanish is divided into insecticides and herbicides and feature the most commonly used pesticides with their respective signal words. Symptoms of pesticides exposure are also shown.

Workers can take this chart home, showing the common materials used for Christmas tree production in NC.

The flipchart also lists routes of pesticide exposure and symptoms of pesticide poisoning. Jim Hamilton also describes in Spanish parts of the body that require greater protection from pesticide exposure in the following video:

Flipchart showing routes of pesticide exposure -- dermal and inhalation.

Fit tests for pesticide respirators were also reviewed by Travis Snodgrass. First cover the filters. If the respirator fits properly, you won't be able to breath in more air. All air passes through the filter. Second, cover where air is released from the respirator when you breath out. With that covered, you shouldn't be able to blow more air out of the mask. This demonstrates that the filters can't be bypassed.

Cover the filters and if the mask fits, you can't pull more air into the mask.

Cover where air comes out of the mask, and you can't push more air out.

The toolkits should be available soon for growers at the NCSU Toxicology Extension website. Some will be available from the county extension offices. We hope to get on video more safety trainings in the coming months and put them on YouTube so that they are available to everyone.

Organic Christmas Tree Powerpoint

2011-06-30T17:12:00.001-04:00

Fertilizer for the Extension Organic Demonstration

I was scheduled to give a talk at a Southern Christmas Tree Conference at the end of May in Atlanta. The conference was canceled, but I had already put together the powerpoint. It was a short talk on the possibility of growing organic Christmas trees. Thought some folks might enjoy looking at it. It's in a pdf format.

Organic Christmas Trees

Any thoughts? Questions? Anyone interested in starting organic Christmas trees?

Trip to the Roan

2011-06-29T11:43:00.000-04:00

Roan Mountain is one of my favorite places. I hadn't been on the mountain for three years, so thought I would travel up there last week to see how the trees are looking.

The Roan has changed tremendously through the years. I have a bit of information about it in my history of the NC Christmas tree industry at: Chapter 2: Why Fraser Fir? This chapter goes into a lot of the natural history if Fraser fir if your interested. As far as Roan Mountain is concerned, logging had stopped by 1937 and by 1941 the US government had purchased the property. Wikipedia has a pretty interesting summary of Roan Mountain as well. Jennifer Bauer Laughlin also wrote a good book on the Roan in 1999 called "Roan Mountain: A Passage of Time."

Balsam woolly adelgid was first detected on the Roan in 1962. Trees were protected in 1963 to establish a source of seed for the fledgling Fraser fir Christmas tree industry in North Carolina. The following is an excerpt from Chapter 5: Early Days: the 1960s.

Spraying trees on the Roan in 1964.

From a forest service brochure dated 1964.

"A 25-acre seed production area was established by the US Forest Service and NC Division of Forestry (Johnson, 1980). “Three hundred trees were marked and subsequently included in the protection zone” (Johnson, 1980, p. 16). Those who worked on the project included Dwight Brenneman, Nursery Superintendent of the Edwards State Forest Nursery in Morganton, Bob Kellison who had been hired that year as a forestry faculty member, John Gilliam, Leonard Hampton and others presumably with the Forest Service. Trees had been thinned in the fall of 1963 to increase cone set, but the shallow rooted habit of the Frasers made them prone to blowing over (Green, 1965).

Trees were originally sprayed November of 1963 with BHC, a precursor to Lindane, and more trees sprayed along the 2 ¼ mile Balsam Road in the summer of 1964 (Green 1965). Treating these areas with insecticides and other areas in natural stands cost an estimated $100 per acre (Claridge, 1963). “Spraying was discontinued in the seed production area in 1974 after many trees had been lost to windthrow” (Johnson, 1980, p. 17). "

Roan Mountain had been the industry's most important seed source for many years. In recent years, research conducted at NCSU has determined that Roan Mountain trees were genetically inferior to other seed sources.

People line up to pull seedlings from Roan Mountain in 1978.

Collecting seed from Roan Mountain in 1997.

The Roan Mountain seedling pull has been discontinued due to lack of interest.

In 2008 when I went up to the Roan to view the rhododendron's blooming, I was struck with how healthy the trees looked on the road back to toll house. Sadly, this year most of those trees were dead. The following video highlights the regeneration of the Frasers, and the larger trees which have finally succumb to the balsam woolly adelgid and other stresses.

Young trees are naturally less susceptible to BWA because they produce juvibione, an insect growth regulator. This is different from hemlock woolly adelgid which attacks all ages of eastern hemlocks. Read more about juvabione on Wikipedia!

So what kinds of pests did we find on the Roan last week? We found balsam woolly adelgid, rosette bud mites, and balsam twig aphid damage. We also found some strange needle problems which I haven't seen before. We didn't see any elongate hemlock scale.

Rosette bud on the Roan.

Twig aphid damage on the Roan

Unidentified needle damage on the Roan.

We also didn't see many Fraser fir cones. There were red spruce cones developing. This seems odd because it's been a rather big year for cones in growers' fields. Guess it has to do with the heat and dry weather last year in June at lower elevations. I'll try to find some weather archives from the top of the mountain. At least I got some photos of red spruce cones. I didn't have any.

Red spruce cones

I also got to see the Gray's lilies starting to bloom. Always a pleasure to visit the natural stands of Fraser fir.

Gray's lily

The crew that went up on Roan Mountain included Brad Edwards, Jeff Vance, Jerry Moody and my daughter Emma.

Elongate Hemlock Scale Lifecycle

2011-06-23T14:00:00.000-04:00

In talking with folks, I find that people are confused about the lifecycle of the elongate hemlock scale.

It is a bit confusing. The same insect can be white (for the males), brown (for the females) and yellow (for the immatures). It's hard to know if they are alive or dead. So here's a bit on the lifecycle that will hopefully make things clearer.

Life for an elongate hemlock scale starts out as an egg which is found under the protective scale of the mother. Here is a photo of the mother flipped over and broken into to show the eggs and the same photo labeled.

These eggs will hatch and the crawler will move out from under the mother scale and find a place to settle down. I actually got by accident a photo of a crawler leaving the mother. It is below. See the crawler at the bottom of the picture? Once again, everything is labeled in the second shot.

The crawler moves around until it finds a place to settle down and start moving. There it will molt, and start creating the scale covering for itself. If it is male, eventually it will fly away so it can mate. That only happens when it is mature. If it is female, it will never move again.

The crawler is the small yellow thing.

The nymphs settle down, and then they produce the adult scale behind them. Here is a photo of one female scale. The yellow portion is the nymph part of the female, and then the brown part is produced.There aren't two scales, just one. It is all white around it because the scale has grown under the waxy cuticle of the needle. It is also almost impossible to tell if it is dead or alive. Under a microscope you can poke it with a pin and it will be moist. This one was alive when I took the photo.

The males are white. They develop into a winged insect that flies off to mate with the stationary females. You can almost think of the white scales as ultimately being a cocoon in which the male is developing. So often when you see the white scales, they are empty because the adult male has already flown off. The adult male is pictured below. This isn't my photo, but it's all I've got of the males.

Now let's put time into the picture. When does all this happen? The following are observations made by Paris Lambdin, a researcher in Tennessee.

• “EHS has two complete overlapping generations per year at sites within the southern Appalachians.” My comment -- That means that you can find all life stages virtually any time through the year.

• “The spring peak for crawler emergence occurred in June while the fall peak occurred in late October into November.”

• “Fall peak emergence for males occurred in August, coincident to the highest number of adult females.” My comment -- That's why we see a second "wave" of white coming onto the trees in August. That's the second generation of males being produced.

• “Gravid adult females were most numerous in late May and October—November.” My comment -- Gravid means they have eggs.

• “Females have three stages of development while males have additional prepupal and pupal stages.” My comment -- That refers to the number of molts each sex goes through before maturity. For females, they are mature when they can lay eggs. For males they are mature when they emerge and fly away.

• “Each female produced 12-16 eggs which hatched over time.”

• “Males do not feed and live only 24 to 72 hours upon emergence. Although capable of flight, males tend to walk across the needles seeking out females for mating.” My comment -- These are the adult males with wings that have emerged from the "cocoon." Some folks were finding the adult males when they were beating the foliage in the spring looking for twig aphids.

Other observations from scientific literature include:

• All life stages found any time of year (Davidson and McComb 1958) – eggs laid throughout growing season

• Mature females may often live for more than one year. My comment -- Isn't that great!

• After a month, the eggs hatch and the first instar nymphs ("crawlers") emerge and migrate to the underside of new needles.

No wonder people were having a hard time figuring out the life cycle. It's complicated! If anyone has any questions, please let me know.

Ways to Put Out Safari: Part II

2011-06-23T09:42:00.000-04:00

On Tuesday Jeff Vance, the County Extension Director in Mitchell County, and I applied some Safari to trees in Little Switzerland. Hopefully this will be on the 2012 Summer NCCTA tour.

We applied Safari 3 different ways:

With a backpack sprayer to the lower 10 inches of the trunk.
With a high pressure sprayer to the lower 10 inches of the trunk.
A full trunk application with a high pressure sprayer.

Sadly our study site received a great deal of rain just an hour after application so the chemical was probably all washed away. But we plan on repeating this in another couple of weeks, and making more applications like this later in the year. We already made a similar application on May 20.

Here is a video of Jeff applying the Safari to the entire trunk. Hope it doesn't make you seasick!

I think that the full trunk spray will be the better way to apply Safari to Frasers in North Carolina. As you can see, these are large, dense, beautiful trees. It is hard to target just the base of the trunk. We didn't even attempt it with a backpack sprayer -- those trees on other side of the road, pictured to the right of the sprayer.

Field where Safari was applied to the base of the trunk with a backpack sprayer.

Even though the trees were smaller, it was still hard with just a backpack sprayer to make sure I was coating the base of the trunk. I used a hollow cone nozzle which I've been using to apply Safari to the trunk of large hemlocks or Frasers. I ended up using about 2 ounces of water per tree to make a thorough application. That's twice as much water as Dr. Cowles was recommending, but I feel like it was necessary to get good coverage. Even with a high pressure sprayer, sometimes there was full coverage all the way around the base of the trunk and sometimes there wasn't.

Though the full trunk spray will take more water, and it will require a high pressure sprayer, it is certainly much faster, easier and cheaper than a normal balsam woolly adelgid treatment that folks have been doing for years. It will just require calibration to apply the targeted 1 pound per acre application rate.

Now is all of this effective at controlling scales and woollies? We still don't know. However, the full foliar application with a high pressure sprayer has been shown to be effective against both pests this time of year. This is with a lighter spray than typically used for woollies -- more of a twig aphid spray. We asked the grower to do this in another portion of the field to make that comparison.

Stay tuned for more results!

Further Results from June 2010 Safari Treatments

2011-06-20T10:45:00.000-04:00

So what are all these people doing? Evaluating balsam woolly adelgid (BWA) control of course!

On June 28 of last year, I reported treating some Frasers at the seed orchard near Mount Rogers with Safari using either a soil or trunk application. See post.

Safari (which is still not clearly labeled for Christmas tree application by the way), can be applied with many methods. It can be sprayed on the foliage. It can be applied to the soil. It can be sprayed on the trunk.

We've seen Safari work very well for BWA control spraying the foliage, but these last two methods have been looked at more thoroughly for hemlock woolly adelgid control, though there has been some work conducted in Connecticut by Dr. Richard Cowles looking at elongate hemlock scale control in Fraser fir. To my knowledge, Cowles hasn't looked at BWA control with Safari.

Safari is a really good systemic. But for it to control BWA when it is applied to the soil it would mean that it was taken up by the roots and moved from the vascular system into the tree bark where the adelgids are feeding. With a trunk application, it has to make one more move -- from the bark into the vascular system and back out to the bark throughout the tree.

Two years ago when Jeff Vance and I tried soil applications of Safari, it seemed to work. But there was also a lot of rainfall at the time.

Last summer it was really dry. When we went back to Virigina in the early fall we didn't see any control with the soil or trunk applications. But I was hoping that control would come later, and last Friday, June 17, I went back to make more observations. Brad Edwards and Teresa Herman came with me and helped me collect samples.

The following pictures are of Teresa climbing up above where the Safari trunk applications were made to get a section of bark, and me looking at the bark samples. (I poke the adelgids with the tip of a pocket knife while looking at it with a magnifying lens).

This time we did see some control with the Safari, but only at the highest rates. We also only saw really good control with a soil drench using the highest rate of Safari, and not with the trunk application (which is of course far easier).

There were a couple of problems with this little study. The first was the lack of rain. There wasn't much after the applications were made, so I would like to repeat the study to see if we can get better results. Also, we might not have used enough water with the trunk applications.

But, even if these work, the rates are rather high. The high rate for the Safari trunk spray is 24 ounces in 1 gallon of water. If you use the recommendations which Valent has for HWA control, you would use only 12 ounces in a gallon, but then apply 1 quart of this spray for a tree that has a 10 inch trunk diameter. That gives a rate of 3 ounces Safari per 10 inch trunk diameter. The rate on the soil drench is 1 to 4.2 ounces per 10 inch trunk diameter. And remember that you can't exceed 2.7 pounds Safari per acre per year -- but then at $115 a pound, who could afford it? With these seed orchard trees, you would quickly exceed the rate.

The foliar sprays are 4 to 8 ounces per 100 gallons -- much more affordable and probably just as easy to do. Perhaps we can get by with a bit less coverage and still get control.

In any case, keep looking at this blog for more updates on how Safari is working with different application methods and timing.

We had a visit from some Mount Rogers ponies on Friday!

Peek-A-Boo

2011-06-15T09:39:00.002-04:00

Yesterday Jerry Moody and I evaluated some treatments for rosette bud mites that a grower made with a couple of new products -- Movento and Mavrik. Movento, if you will recall, is a new systemic made by Bayer. Last year it looked like one of the trees that had rosette buds recovered after a spring Movento treatment. Mavrik Aquaflow is a synthetic pyrethroid that Jerry Moody has had a couple of growers use for rosette bud mites. The Avery County grower used a mistblower to apply the products. To date we've never seen any mistblower applications work that well for rosette buds, though some folks have gotten good enough control with a mistblower using Dimethoate. The hope was that the Movento would work better through a mistblower since it is such a good systemic.

Of course the buds for next year are just forming now, and it is too early to go through a field and pick out the rosette buds. So Jerry and I randomly pulled some new growth on trees that had rosette buds, and I looked at them under the microscope to see if any mites were present in the developing tissue.

The results... Not going to say yet. Sorry. Still too preliminary. But I would like to share this photo I took at the Watauga Extension office of a rosette bud forming. This is a shot of a bud sliced down the middle from top to bottom. You can see that there is a cavity forming where the shoot should be and about 10 rosette bud mites -- and maybe even an egg. The same photo is seen below with everything labeled.

And obviously, since I was finding some mites, one of the products didn't work -- but one seemed to! I think I'll go back next week and collect more samples and spend some time taking photographs which I'll share on my blog. It will probably be mid July before I can give the results of this little study after the rosette buds have clearly formed and I can see throughout the block how well things are working. So stay tuned.

So Why do Spider Mites Crash?

2011-06-13T10:56:00.000-04:00

It brings to mind a car crash but of course that's not what I'm talking about. I'm talking about a healthy, reproducing population of spider mites that goes into a sudden decline.

I hope you've been able to witness it happening, because it gives you a good feeling. After all, you are getting free pest control. For once, nature is being a help instead of a problem. But how does it work?

Close-up of a female spruce spider mite.

Spider mite numbers decrease for a number of reasons, but it usually revolves around the weather. Spider mites like it hot and dry. Why? The warmer it is the faster they mature and reproduce. They also prefer dry weather because wet weather keeps most of their eggs from hatching. Sometimes you'll even see the mite eggs and even the mites themselves turning black as a fungus consumes them.

But humidity also plays another role. The predatory mites that feed on spider mites do better in humid conditions. So wet favors the good bugs (predatory mites) and dry the bad bugs (spider mites).

For a view of predatory mites, click here! This publication is for greenhouse growers, but the mites are the same.

We've already been seeing spider mite numbers rise and fall this spring in Fraser fir fields in western North Carolina. There are still a few eggs present in some of these fields which might allow the spider mites to come back later on in the summer or fall. In fact, if the fall is dry that is when spider mite numbers really tend to rebound, making them a problem on harvested trees. But for some of these fields, no further action will be necessary.

So how will you know if spider mites are rebounding? You scout, of course. Scouting for mites doesn't have to be a lot of work. Just going out and checking a few trees every month or six weeks -- especially those prone for mites -- will help you keep track of their numbers. Look at some shoots with a hand lens. That's the best and easiest way to look for mites.

Scouting for spider mites with a hand lens.

For a complete review of spider mites and their control see the Christmas tree note #29: Spruce Spider Mite on Fraser Fir.

Going Mobile!

2011-06-08T12:57:00.001-04:00

The Fraser Fir IPM Blog has gone mobile!

Now when you access this blog from your mobile phone, you will get a slick new look that will allow easy viewing when you are in the field or on the go.
Enjoy!

Some Results on Pest Control

2011-06-01T14:48:00.000-04:00

We're seeing more twig aphid damage than I anticipated. After all, it wasn't easy to find twig aphids in April. Plus we had lots of rain and cooler temperatures which tend to reduce the survival of the aphids. But they are well adapted to western NC, and they have ended up causing some damage.

BUT... with all the rain, a lot of the damage is disappearing. I spoke with Bryan Davis who told me that he is seeing less needle curl in fields this week even than last week. Thanks to the rain, the majority of this curl will go away.

This leads me to some data to report from my current studies.

FALL TWIG APHID CONTROL: Last fall, Jerry Moody and I treated some trees October 18, 2010. Really we were trying to see how late you could treat in the fall and still control elongate hemlock scale. But I also wanted to see if the treatments would control twig aphids the following spring. We tried Safari (applied to the foliage with a high pressure sprayer at 8 oz/100 gallons), Lorsban, and the standard Dimethoate + Asana.

I did evaluate scale control this spring, and none of the products worked well. This wasn't surprising as mid October is probably too late to get much scale control. However, I also evaluated BTA control this spring with these fall treatments and those results are pictured here.

Remember that I evaluate twig aphid damage by either walking around the entire tree (which makes me dizzy!) or working with a partner. For these observations, I worked with Jerry Moody. We walked on either side of the tree and estimated the percentage of 2011 new shoots with needle curl each on our respective side -- then we come to an average figure for that tree. These result in the numbers in the first column (% shoots with curl) -- averaged for all 20 trees. The next column has the percentage of the 20 trees with at least SOME needle curl. The third column has the percentage of 20 trees with 10 % or more of the needles curled. This is the point where most growers tell me the damage is bad enough to affect the value of the tree. Of course remember that the needle curl will decline over the next several weeks, so all of these numbers will go down. Still, the comparison now when the damage is at its greatest tells us how well the products are working.

Obviously, neither the Lorsban nor the Safari are giving us any twig aphid control when applied in the fall. The Asana + Dimethoate worked well, though not perfectly. In fact, Brad Edward's observation this spring has been that the Asana in the fall isn't working quite as well as the Talstar applied in the fall. It works, but a bit of curl gets through. These results bear this observation out, and in fact the first year I did this type of work at Omni Farms, that was our observation. Still, the Asana + Dimethoate gives good enough control and it would be more effective against scales.

SPRING CONTROL WITH SYSTEMICS: So how well does Safari and Movento work in the spring? Jerry and I applied these products at two farms, treating on April 18, 2011. In this instance we applied the Safari to the base of the tree trunk and not the foliage, using a rate of 1 pound per acre. At two farms we did this with a high pressure sprayer, and at one farm just with a backpack sprayer. The Movento and bifenthrin are applied with a high pressure sprayer to the foliage.

The results again demonstrate that Safari isn't giving us twig aphid control. Practically all the trees had some needle curl when treated with Safari. The Movento gives fair control. A lot of trees have some curl, but hardly enough to worry about. The bifenthrin is of course the best.

At these two farms there was also scale and woolly adelgid. We will be looking at the control of these pests later on in the summer, so stay tuned!

OTHER OBSERVATIONS THIS SPRING: Once again, several people I've spoken with this week are commenting on spider mite activity. The rain is reducing mites to some extent -- probably by increasing predator mite activity, but it is still important to scout for spider mites and make sure they don't damage new growth. The good news? All of this hot weather should be taking care of any rust mite issues!

Ways to Put Out Safari

2011-05-23T13:30:00.000-04:00

On Friday, Jeff Vance and I tried putting out Safari in some Christmas trees. We used either a backpack sprayer with a hollow cone nozzle, or a high pressure sprayer. With either sprayer, we were targeting the lower 10 inches of the trunk.

Unfortunately, I think the application was uneven. On some trees, there was good coverage all around the trunk. This is important because only when the entire trunk is encircled with spray will the entire tree get a dose of the chemical. But on other trees, the entire trunk was not completely covered.

Jerry Moody also tried applying Safari to his trees. In his case, he targeted the entire trunk of the tree, treating from both sides, and not just the base. He ended up using more water but he made a more dilute spray to target 1 pound of Safari per acre. And he thought he was getting excellent coverage, as well as moving quickly through the trees.

Next month when Jeff and I spray, I think we will compare different application methods of Safari using a high pressure sprayer -- treating just the bottom 10 inches, treating the entire trunk, and treating all the foliage lightly -- like a balsam twig aphid spray. That way we can find the quickest, easiest method of application. We hope to have this field on the NCCTA summer tour next year in 2012.

Getting the Most out of Safari

2011-05-11T14:28:00.000-04:00

On Monday and Tuesday I was applying the active ingredient, dinotefuran (aka Safari), to hemlock trees for hemlock woolly adelgid control. Learning how well this works should help with elongate hemlock scale control in Fraser fir, so even though this project isn't related to Christmas trees, I think it's still important.

The label for the trunk application with Safari has a range of rates from 12 to 24 ounces per gallon. However, in other literature that the chemical company, Valent, puts out, it says just to use the 12 ounces per gallon rate, so that is what I did on Monday when I treated hemlocks by myself at a site in McDowell and on Tuesday when I worked with NC Forest Service folks, Brian Heath and Craig Lawings treating trees at the Crossnore Nursery in Avery County.

The label also says that one gallon should treat about 40-50 inches cumulative trunk diameter. Therefore, one quart would treat a 10-inch diameter tree. However, it also says to treat until run-off. When I applied the product on Monday, I was treating until run-off and ended up treating about 100 cumulative inch trunk diameter -- or twice as much. We'll see if well it works. On Tuesday we tried to stick to one gallon treating 40 inches. The first thing we did was calibrate to see how long it took to spray out an ounce. This photo shows Craig spraying and Brian keeping track of time.

With the sprayer he had, it took about 9 seconds to spray out an ounce. Therefore on most trees we treated, Craig sprayed between 2-4 minutes on a single tree trunk. This photo is a close-up of the bark of a good sized tree after treatment. You can see the foamy bubbles of the chemical on the trunk.

You are supposed to treat all the trunk including the root flares to about 5 foot. This photo shows a tree trunk after treatment. These trees were previously measured and marked by Brian and Craig -- you can see the metal tag on this tree with the identification number.

One question we had was if the chemical would be taken up well by trees with a lot of lichen as is shown in this photo. We tried to make note of trees with exceptional amounts of lichen so we can follow them over the coming months.

Here is a photo of Craig spraying as well as a video. Many of these trees are right on the Linville River. This is a recommended treatment for trees near surface water as you are just spraying the trunk of the tree and not the soil.

A link to Joe Chamberlin from Valent applying the trunk application is found here. The video is on YouTube and is for emerald ashe borer, but it is the same basic method.

Many of the trees we treated on Tuesday were hard to get to. Brian had to get out a machete and hack a path to the tree then hack around the tree so Craig could get to it with his sprayer. That's why it's a new kind of hack and squirt!

These trees aren't doing well. We'll see if the material can bring them back. This photo shows the state of some of the trees as seen from the highway.

We did more than 30 trees on Tuesday. Brian and Craig will end up treating more than 70 trees this spring. That will give us a percentage of how successful we end up being! The trees I treated on Monday are in a bit better shape. This photo shows some of them taken last summer. But then I also used about 1/2 the recommended rate, so that will also be interesting to follow. I treated close to 30 trees on Monday.

As usual, I will post additional results and observations as they become available.

MITES!!!

2011-05-05T19:47:00.000-04:00

I'm surprised how many spruce spider mites I'm seeing this spring, considering how wet it's been. I have been in several fields where individual trees were absolutely cover in mites.

This terminal is covered up in spider mites and their eggs. There is even some webbing between the needles which is where spider mites got their name.

This shot shows my fingers after handling the mite covered terminal. This is the color of squished mites!

These trees were at the site of our organic study. I think I will treat them all sometime in the next few weeks. What's complicating this is that the new growth is out. I'm afraid I'll burn them which is why I'm going to hold off a few weeks.

The final shot I'm posting today shows the difference in the ground covers between the organically grown trees, which are full of grass, and the "late" organic trees that are still being grown conventionally with Roundup use. We will switch to organic production the last three years before sale.

The organic is in the background, and that's where Brad's mowing. In the foreground are the "late" organic, which haven't been treated yet with Roundup. There were areas of the field where the clover was keeping out any weed problems. There appears to be much more biodiversity with the use of Roundup. Hopefully this summer I can get some data along these lines. But for right now, a picture is worth a thousand words!

Ready Or Not!

2011-04-27T13:48:00.000-04:00

I saw my first Fraser fir with buds breaking yesterday. So ready or not, it's spring!

The weather hasn't cooperated much in getting spring pesticides out. If you got behind and buds are breaking and you need to control twig aphids, an application of Dimethoate should control the aphids even in the broken buds. This will also knock back spider mites and rust mites. This works best when applied with a high pressure sprayer -- not with a lot of pressure, but with good coverage of all the new growth. However, even with a mistblower, it still may help.

So far this spring, though, I haven't seen many fields with enough twig aphids to worry about. With all the rain we're getting, it will greatly lessen the impact of twig aphid damage and spider mites as well.

The key is to not forget the spider mites as the summer progresses and especially if the rains stop. Late season spider mites can sneak up on you. Even if you use a good miticide in the spring, that is no guarantee that spider mites won't become a problem again by late summer or fall. Even a quick job scouting is better than not looking at all.

I guess the point of this post is to not worry if you haven't gotten all the insecticides you intended to before bud break. It is better to not apply a pesticide than to put it out in poor conditions such as too windy or rain on the way. Just keep an eye out for developing problems. Nine times out of ten, pests like twig aphids and mites won't be bad enough to worry about.

Honoring John Fraser

2011-04-26T18:16:00.000-04:00

Today marks the 200th anniversary of the death of John Fraser, the man for whom the Fraser fir is named.

I hope you were able to read the article I wrote for LIMBS&NEEDLES about John Fraser. He was a remarkable man, exploring this country and its rich plant life when it was nothing but wilderness.

He wasn't the exacting botanist that Michaux and others were. He didn't leave any notes. Some said that he explored and collected solely for financial gain, and for that reason should be looked down on. But in my opinion, he found a way to make a living doing what he loved. Like the Fraser fir which tenaciously survived on the highest mountains following the last glaciers, John Fraser didn't require anyone's approval. He was self taught, self motivated, and carved out his own name and niche. His legacy is the perfect symbol for the North Carolina Christmas tree growers that followed him scores of years later, who were also self taught, self motivated, and carved out an industry where people said it couldn't be done. Now the Fraser fir is recognized all around the world as one of this planet's best Christmas trees, and it still proudly bears the name of the man who first brought it down off the mountain.

So thank you, John Fraser. Your tree is still well loved and we trust it will be well into the future.

Pest Problems Caused by Economics

2011-04-20T20:15:00.000-04:00

With problems in selling trees come increased problems with pests. As trees keep getting larger and start growing into each other there is more opportunity for algae and other pest problems. These are related to the lack of air movement around the trees.

In a field I visited today there were actually 3 problems causing discoloration of the foliage -- algae, elongate hemlock scale, and a disease called Rosellinia.The fungus grows in the interior needles, causing them to shed. The fungus grows in mats and produces the fungal spores pictured here.

The remedy for Rosellinia fungus and algae is to improve the air movement by keeping weeds in check, butt pruning trees, and removing trees that are growing into each other.

You can also control algae from developing in the foliage that was produced last year by spraying right at or just after bud break with the copper based fungicide Kocide. For information on algae control check out past entries on algae.

Putting Out Systemics

2011-04-18T16:38:00.000-04:00

Today Jerry Moody and I put out Movento and Safari, both systemic materials, at two different farms.

Movento is a systemic that is supposed to be quite mobile in the plant. It requires the use of an adjuvant to help it be taken up. We used a product called Liberate. The last couple of years that we've worked with Movento it provided great control of balsam woolly adelgid, decent control of twig aphids, but hardly any control of elongate hemlock scale. In one tree last year, it also looked like it control rosette bud mites so we were interested in that too.

This year we applied Movento in two fields that had it all -- twig aphids, scales, rosette buds and woollies. We used a rate of 10 ounces per acre of Movento and 2 pints per 100 gallons of Liberate. Both of these are the highest rates. At the one field the trees were small and we sprayed about 200 GPA. The other field had denser, larger trees so we used double that.

The Safari applications were the new trunk sprays. These may control both woollies and scales but we don't anticipate them having any activity against twig aphids or rosette bud mites. We used a rate of one pound per acre.

Dr. Richard Cowles from Connecticut has been doing this technique for several years. He talked about it at the NCCTA in Boone this spring. He has been recommending an application with a backpack sprayer, wetting the trunk of the tree from about 10 inches to the ground. The rate he uses is 3 1/2 ounces Safari in 3 gallons of water. You use 1 ounce of this solution on each tree, treating the tree from both sides. That is because the Safari will move up the tree, but not from one side to the other.

His recommendations are based on lighter density trees that are also butt pruned. That's not the type of tree we grow here in North Carolina. So we only used this backpack application at one farm. We decided to also apply Safari to the trunk of the tree North Carolina style! We treated the trees with a high pressure sprayer. Again we aimed for about one pound per acre, treating each tree from opposite directions. But since we are putting out more water per tree (about 50 gallons per acre) we mixed the Safari differently. We ended up using 6 ounces of Safari in 20 gallons of water. This should treat 4/10ths of an acre. This type of application went very quickly.

A short video of Jerry applying the Safari this was is seen below. The respirator is not required on the label. On a couple of trees he sprayed twice -- that's because he missed the trunk the first time! He said you could tell when you hit the ground and not the trunk by how it sounded.

At the one farm we also used an Onyx knock-off called Sniper. This is a bifenthrin product (same active ingredient as Talstar) but it is mixed differently. It uses a different carrier, and it has 2 pounds active ingredient per gallon instead of 0.67 pounds. That means you don't need as much. We tried using the same amount of chemical as the full 40 ounces per acre of Talstar -- that ends up being almost 13 ounces of Sniper. We haven't seen that bifenthrin gives much control of scale in NC, but Cowles has said that the Onyx works well, so we'll see.

Unfortunately, it may take several months before we know how well any of these treatments work. I'll keep you posted.

Mites on the Move

2011-04-14T08:53:00.001-04:00

Finally got out in some trees yesterday, and didn't have any problems finding mites -- both rust mites and spider mites. The spider mites are just now starting to hatch out and move around. Taking a quick check on mites in your trees will help you decide what pesticides to apply this spring, or even if you can skip a treatment.

The March 10, 2010 post "Spring Insecticides for Pest Control" gives a good summary of materials you can use this spring. The following image reviews how well some of the common materials control different pests. The big X means it works really well. The smaller x means it only works somewhat and might need an added material to give really good control.

Other miticides that you might use include the following:

Sanmite which like Envidor controls all stages of both spruce spider mite and hemlock rust mite
Savey which controls the eggs and immatures of spider mites -- no activity against rust mites
Apollo which has the same type control as Savey
Floramite which should control all stages of spider mites

It's always good to rotate materials, especially with pests like mites that have multiple generations each year.

Remember that Thionex will no longer be available for sale after July 2011, and you can't use it after July 2012, so don't purchase now more than you can use.

For a listing of pesticides labeled for Christmas trees and links to the labels and MSDS sheets, view our new pesticide page.

For information about farm and pesticide safety, go to our new safety page.

Pests Getting Started This Spring

2011-04-05T15:02:00.000-04:00

Hasn't the weather been fun the last few weeks? Talk about a yo-yo! That's hard on us, and it's hard on bugs too. Warm weather allows them to mature and reproduce quicker and survive better. Cold and wet has the opposite effect. So what are people seeing now?

BTA

I haven't been out in the field yet, but Doug Hundley has reported seeing three instars of twig aphids. If you will recall, these aphids begin hatching from their eggs in mid to late March. They molt four times before becoming an adult which can produce more live young. So what does that mean? What's an instar?

Remember that insects don't grow like mammals do. I have a new puppy, and every few days I think -- Gosh he seems bigger. Insects don't do that. They grow in stages since they have to shed their skin (molt) to get bigger. Different species of insects mature differently. Twig aphids have four molts so there are four instars. If Doug was seeing three different sizes of aphids, that means that the twig aphids are hatching and growing and fairly far along with their life cycle. But also remember that twig aphids hatch over a several week period. The oldest aphids he saw were probably the first ones to hatch. Usually it takes until April 15 for all the aphids to hatch out. I would think that with our periods of snow and cold which seem to come every week, that it will take that long for the twig aphids to completely hatch. However, if you are using any insecticide except for granular Di-Syston or Thionex, any materials you spray now will work fine. It will last long enough. These two work best when applied after all the eggs have hatched.

So is it best to wait later in April to early May to treat for twig aphids? Not necessarily. First of all, the longer you wait, the more you at the mercy of the weather. The other factor are cones. Cones can reduce the effectiveness of insecticide applications. The bracts on the cones protect the aphids. When the cones are very small, the aphids can't get under these bracts. So if you have a lot of cones and are spraying for twig aphids, it would be better to treat sooner than later. Otherwise you will have to remove all the cones. Of course, you'll probably do that anyway.

Dimethoate has proven effective even when the cones are more mature, so if you get caught with bigger cones, consider switching to that material.

HRM

Brad Edwards reported seeing some rust mite activity recently. The presence of rust mites in the spring may affect what pesticides you want to use. If you treated in the fall with Talstar and don't have and twig aphids this spring, you might still need to spray if you have rust mites. And if you were going to spray anyway, the presence of rust mites may make you want to add a miticide. Remember that Talstar, Apollo, and Savey don't have any activity against rust mites. They only control spider mites. Dimethoate controls rust mites but not the eggs. If this materials is used -- especially early in April -- you might have to reapply come May. Sanmite and Envidor control all stages of both rust mites and spider mites, making them worth the extra cost.

So how do you know if you controlled your twig aphids last fall or if you have rust mites? That's right. You need to scout!

Updated website on pesticides

2011-03-14T12:34:00.000-04:00

The web site with pesticides labeled for Christmas trees has been updated. Click here http://www.ces.ncsu.edu/fletcher/programs/xmas/pesticides/index.html for the link.

There is a lot of information at this site. Practically all pesticides labeled for Christmas trees are listed. That includes insecticides, herbicides and fungicides. There may be some others that are labeled. Glyphosate alone has multiple products that can be used in Christmas trees. But hopefully this web site will include most that are regularly used by the industry in North Carolina. (If there are others you would like to add, just let me know!)

On the site is the following information for each material:

The common name -- that's the name you see on the package.
Type of pesticide and the uses for the product.
Active ingredient -- that's the name of what actually is working in the pesticide.
Active ingredient concentration -- let's you know how many pounds of active ingredient are in each gallon or pound.
The chemical family -- so you can see which materials are related to each other.
The manufacturer.
The EPA registration number -- you need to list this in your pesticide records. Also, when you talk to NCDA&CS folks, have that number so they can quickly pull up the product.
Use/Signal word -- whether the product is labeled CAUTION, WARNING or DANGER.
REI -- the restricted reentry interval. Be careful though. What is listed is for normal reentry. There may be additional cautions on the label for special circumstances.
The rate -- which includes the maximum amount that can be applied each year when applicable.
PPE -- the personal protective equipment required for applicators. Again caution as there may be special PPE required for handlers or other workers or uses.

Also on this site is a link to all the labels and MSDS sheets for these products.

This information is provided for your convenience. If you see any errors, please let me know. Updates will be made as necessary. But be sure to review the label that comes with the material you are using. That is what you should always go by.

Di-Syston 15 G

2011-02-21T14:24:00.000-05:00

In recent extension meetings, I have been telling folks that Di-Syston 15 G will no longer be legal to use after July 31, 2012. This is incorrect. According to documentation provided by Bayer CropScience, "Distributors, retailers and growers can sell and use Di-Syston 15G on Christmas Trees until stocks are exhausted." I apologize for any inconvenience.

Pennsylvania Christmas Tree IPM Manual

2011-02-09T14:05:00.000-05:00

The folks in Pennsylvania have put together a new manual on integrated pest management for Christmas trees. Click here for a free pdf of this manual.

Additional Cowles Article

2011-02-08T14:05:00.000-05:00

Dr. Cowles sent me another article for everyone to review. It is called, "Optimizing a Basal Bark Spray of Dinotefuran to Manage Armored Scales in Christmas Tree Plantations." Click on this link (the name of the article) to view this pdf file. Be patient, it takes a few moments for it to become clear on your screen.

Visiting Scientist Richard Cowles

2011-01-31T14:01:00.001-05:00

On Friday March 4, Dr. Richard Cowles with the Connecticut Agricultural Experiment Station will be speaking about scale control in Christmas trees.He is an expert on scale control, working with both elongate hemlock scale and Cryptomeria scale. He also has worked with the systemic insecticides such as Merit and Safari for hemlock woolly adelgid control. Attending the NCCTA meeting would be a great opportunity to learn from and talk to this expert.

The following are two references by Dr. Cowles that you might want to look at before the meeting.

2008 Scale Efficacy Trial: In this paper is information about Judo, Onyx, Botaniguard and Safari for elongate scale control
Connecticut Weekly Agricultural Report, April 7, 2010: A New Method for Managing Armored Scales in Christmas Tree Plantations: This report has information about trunk applications of Safari for scale control in Christmas trees

Pesticide Safety Web Site

2011-01-14T14:43:00.001-05:00

Farm safety is a big topic these days. As stated on the OSHA homepage for agricultural operations, “Agriculture is one of the most hazardous industries in the nation. Farming is one of the few industries in which the families (who often share the work and live on the premises) are also at risk for fatal and nonfatal injuries.” These dangers are compounded when most farmworkers are Latino, and even Spanish may be their second language. Their understanding of English is often limited, making them an especially vulnerable work force.

To help growers comply with existing laws, and to draw together resources from many states, a Christmas tree farm safety web site has been developed.

Information is organized in several categories including general farm safety, equipment safety, shearing safety, pesticide safety (by far the biggest section), and harvest safety. Many resources are available in Spanish. There are links to pertinent laws, laws for record keeping, forms to record worker training, and videos on many topics.

So check it out at: www.ces.ncsu.edu/Christmastrees/farm-safety

How Things Have Changed

2010-12-13T16:31:00.000-05:00

I found an important photograph quite by accident about a week ago. It was on a postcard in The Muses bookstore in Morganton. The photographer is Christopher Smith (www.christophoto.com), who is in Asheville and specializes in weddings and landscapes. I contacted Mr. Smith and he graciously allowed me to use his sopyrighted photo in my blog and my talks on hemlock woolly adelgid.

Why the interest in his photo? It was taken in 2001 at Linville Falls. His photo clearly shows the hemlocks growing in the spring against the dark shadow (note the magnolia blooming). This was before the HWA had made an impact. I didn't have a photo from this time, and even if I didn't, it wouldn't have been that good. You can compare it to my own photograph which I took on Labor Day 2010. The difference? A picture is worth a thousand words, and words can't describe the irreplaceable loss this pest has made in western NC and elsewhere along the east coast.

Chris Smith photo, 2001

My photo, 2010

Needle Drop in Scale Infested Trees

2010-12-09T13:25:00.000-05:00

This week I finished taking data on the needle drop in cut branches from scale infested trees. I reported on the experiment on November 10th when I set it up. The experiment worked worked well in that there was needle drop, but since there was too much needle drop, I guess it worked a little too well!

Many of the needles shattered as depicted in the photograph to the left. On some branches, almost all the needles fell off. That is definitely not something we're used to seeing with Fraser fir. If you look closely at this photo, you can see that this was from a scale infested tree, but the uninfested trees were just as likely to shatter -- just not as badly.

The room that the branches were stored in was very hot. It's an unused room at the Mountain Horticultural Crops Research Station office, and both Jeff Owen and I had shoots stored there. They kept the door shut and the room, which faces the sun, would often be too hot to be comfortable in. The shoots in the buckets faired the worse, dropping many needles. The shoots that were were kept dry kept almost all of their needles to the end of the study, but they dried out and became very brittle.

So did scale infested trees drop their needles more than uninfested trees? The quick answer is, "Yes." The results are summarized in the following table which lists the average percentage needle drop for all 15 trees in each group (infested and uninfested) for both the trees stored with water (wet) and without (dry). On average, 43.1% of the needles on scale infested branches had shed their needles while only 27.8% of needles on uninfested branches had shed. Also note in the table that there was more needle drop in the field on scale infested trees (first column labeled "From Field"). I had reported this back in November.

If you look at individual trees, by the end the experiment 47% of the infested branches in water had shattered a third or more of their needles (much like the photo above) while only 27% of the uninfested branches had more than 1/3 needle drop. Of course, that is much more needle drop than would be expected from cut Fraser fir. Remember that these branches spent less than 24 hours without water. Needle shed should have been at a minimum, and was through the first couple of weeks. Only one tree shattered its needles in week 2, and that was a scale infested tree. But by week 4, there were needles everywhere.

If you are a very perceptive observer, you will also note in the table that I only report on 1st and 2nd year needle drop and not 3rd as I said I would do back in November. That is because some of the 3rd year needles were under water in the bucket, and I didn't trust the results from them. In this photo, taken in week 2, the discolored needles had been underwater. These were more likely to fall off.

Generally results were along the lines I anticipated -- more needle shed in scale infested trees -- but the data were far from pretty. After all, there were uninfested branches that totally shattered their needles, and there were scale infested branches with very little needle shed. There were trees where one branch placed in water shed their needles, and the other branch from the same tree also in water hardly did at all. On about half of the scale infested trees, of the two branches taken, the one with more scale had less needle drop. So, I am not real happy with the results. I think I'll repeat this experiment next year either in January or next harvest season to see if I can get some clearer results.

I do think I can safely say the following: there appears to be slightly more needle drop in infested trees. However, needle drop occurs for a variety of reasons, and scale infestation is definitely not the over-riding factor. Still scale infested trees are messy. The scales themselves drop off as the tree dries out. There also appeared to be some fungi growing on older scales as my last picture shows.

This quick little study just confirms what many people had been telling me, that scale infestation doesn't help the quality of cut trees.

Updated Results on Scale Control

2010-11-18T14:04:00.000-05:00

I reported in July on some control results of scale treatments I had made on June 20. To recap, I used a backpack mistblower at Dale Cornett's in Watauga County. I used either Asana + Dimethoate, Lorsban, Movento or Safari. In July I went back and the Safari and Asana + Dimethate both gave control, but only about 85% control. This was a bit disappointing. The other two didn't work, but then Movento is a systemic and slow acting, so I vowed to return and see if time would improve the results.

I went back today and now the Dimethoate + Asana and the Safari both had 100% control. I did not see any live scales at all. It was hard to find shoots that had scales on them, and they all looked dried up just by looking at the shoots. There was no white cotton at all.

The Lorsban and Movento treatments were still similar to the untreated check trees. They still hadn't worked.

So not only did control improve with the Safari, it did with the Dimethoate + Asana as well. Maybe we go back too quickly to evaluate control. These materials apparently keep on working.

Remember that currently Safari does not have a Christmas tree label -- only a nursery label. So if you aren't digging your Fraser fir, you're not supposed to use it. Hopefully that will change next year. These results are certainly encouraging.

Research out of Connecticut has indicated that Safari will controls scales with a trunk application, at a reduced rate per acre. These treatments can be made in April through June. I plan on trying this next year.

Scales & Needle Drop

2010-11-10T09:03:00.000-05:00

Why does Meghan Baker, Watauga County Extension Agent look so happy? We were done collecting shoots! Meghan helped me on Monday collect shoots from a grower's field to help determine if elongate hemlock scale infested trees are more likely to drop their needles after the tree is cut. Several growers and Christmas tree retailers have told me they think scale infested trees are more likely to drop their needles. Other pests such as spider mites and balsam woolly adelgid cause similar problems. Hopefully we'll soon know if it's true of elongate hemlock scale as well.

Meghan and I collected shoots off of 15 infested and 15 uninfested trees. We took three years worth of growth plus a little bit of the fourth year branch in order to stick the shoot in our trays. Since scale goes back multiple years, we wanted to see how it was affected older needles.

Our samples were paired. We took two branches from one area on the tree and another set of two branches from another area, usually on the opposite side of the tree. One of the paired branches will stay in the bucket with water. The other one goes in a tray without water. Having two sets of these pairs will allow us to compare results within a given tree. Needle retention varies greatly between trees even without pest infestation. It can also vary with different positions on a tree. Most of our samples came about 1/2 way up the tree and some branches I cut were practically against the trunk.

This is what all 120 shoots look like today. Each branch is labelled so I can keep track of what tree they came from. Half of the branches are in buckets of water and half in styrofoam trays without water. Yesterday I took data on the scale infested branches, estimating the percentage of needles with scale on the 1st, 2nd, and 3rd year growth. Infestation varied widely. I have some branches with 2nd and 3rd year needles having 100% infestation, and others with less than 25%. I also marked if there were other problems with the foliage such as twig aphid damage or small, yellowed needles that are also more likely to shed. If there was any needle drop already, I also made note of that.

In a week I will take each branch and lightly rub my hand over the foliage and estimate the percentage of needles that fall off, again keeping track if they are from the 1st, 2nd, or 3rd year shoots. I'll take ratings again after 2 weeks, and final data after 4 weeks. Already I'm finding that the 3rd year needles of heavily infested trees were falling off the trees in the field. These trees are such heavy density so it probably wouldn't have mattered, but if they keep coming off in the home, it will cause a mess.

I want to give special thanks to Jeff Owen who has conducted several experiments like this looking at other factors affecting needle drop. He was able to help me with the experimental design. Much of this type of research was originally conducted by Drs. Eric Hinesley and Gary Chastagner. And of course thanks to Meghan for her help, and for the grower, Johnny Greer, who donated his trees. Also a big thanks to the Mountain Horticultural Crops Research Station at Mills River who are donating some space in a spare room to mimic someone's home. (I promise to sweep up all the needles!)

I'll let you know how it all turns out.

More Algae Control Results

2010-10-28T20:33:00.001-04:00

Jerry Moody, Doug Hundley, and I rated the trees treated in Avery County for algae control today.

Treatments. The treatments are all listed on blog posting from August 27. But I'll list them again here.

Untreated check
SA-20 disinfectant @ 1 teaspoon per gallon on May 5
Daconil @ 3 pints per acre on May 5
Dithane @ 1.5 pounds per acre on May 5
Kocide @ 3.5 pints per acre on May 5
Kocide applied twice on May 5 and May 19
Kocide on May 19
3% bleach solution on September 25
Kocide on September 25

All treatments were made with a backpack mistblower except for the 3% bleach solution which was applied with a high pressure sprayer.

How we did it. Taking ratings was hard. After all, some trees don't appear to get algae at all -- whether because of their position in the landscape, their proximity to other trees, or resistance is anyone's guess. So we first looked to see if the trees had algae on older needles. The trees with algae on older needles are the only trees we counted in the data. Then we looked specifically at 2009 growth and gave it a rating of 0 to 4 where 0 = none, 1 = very light, 2 = light, 3 = moderate, and 4 = heavy. We examined 15 trees in each treatment.

Results. The results are to the right. Remember that we only counted trees that had past algae. So, the higher the pecentage of trees with no algae in 2009, the better the product was working. And obviously the lower the algae rating, the better the product worked.

The best controls were with SA-20 disinfectant and Kocide applied May 5. The Kocide applied later in May didn't work as well. Nothing worked in the fall. Again, these materials will prevent algae from developing, not cure it.

These treatments were applied to a single row and the treatments are in order going up the hill (all except for the check row which was between the Daconil and the Dithane). There was definitely more algae the farther up the hill you went, and so that may be why SA-20 disinfectant worked well. That's also why the fall applied treatments had more algae than the check.

What next? I'd like to look further at Kocide and perhaps some disinfectants next spring. I'll also be looking for some growers who will be interested in trying the Kocide. Unfortunately it looks like if you want to control algae, you need to treat for it the last 2-3 years before harvest every spring. Once it occurs, there is nothing you can do about it. Treatments will be harder to make on large trees growing together, and in fact this is where we find the most algae. So keeping a good spacing between trees is important.

More Info on Fall Needle Shed

2010-10-27T09:34:00.001-04:00

Jeff Owen sent me the following information to further discuss what's happening with fall needle shed:

Stressed Fraser firs will shed interior needles in late September or October. It usually occurs right in line with fall color on hardwood trees. Usually it is a sign of drought stress, but there may also be a fertilizer deficiency or toxicity contributing to the problem. We have not been able to point to a single nutritional problem contributing to interior needleshed. But I have seen internal needle shed in fields that have low phosphorus, or calcium, and/or very high manganeses or sulfur.

I have observed several fields where the needle shed is widespread on the southwestern aspect and very light as the field shifted to more of a northern aspect. Even a subtle difference in aspect made a big difference in this problem. In a drought stress year, most growers will have 1 to 5% of this problem in their older trees, but I have seen one or two fields with as much as 30% of the trees affected.

Needle loss problems seldom show up before trees are of a marketable age and size. Trees greatly increase the amount of foliage with each progressive year. This creates an increasing demand for water and nutrients. Factors which may have been adequate or marginal for a smaller tree become limiting as the tree grows. The failure of symptoms to be expressed in younger trees has often lulled growers into complacency only to be surprised by needle loss in trees already tagged for market.

When needles shed out to the new buds in the fall, I think it is a different scenario. In that case I have observed 3 different factors in play: salt, calcium deficiency, and Phytophthora root rot.

Salt injury at some time in the current year can cause needle loss all the way out to the bud typically without killing the branch or bud (although sometimes they die too). I have seen late fall needle loss and grey-black necrosis in the bark and wood of branches that were spring fertilized with "plops" of 10-10-10. Sometimes the whole tree sheds, but sometimes only one side or a coil of branches climbing up the stem from damaged roots will lose needles.

Calcium deficiency will induce fall needle loss in the top or middle of a mature Christmas tree. I have seen white pine and Frasers with similar symptoms in the same field. All the needles on a branch can turn bright yellow, then brown, then drop off. The branch and buds live although growth can be stunted in the following year. I have seldom seen more than 1% or 2% of trees with symptoms of calcium deficiency. Yet these trees may reflect a field-wide deficiency. The concern has been that other trees in the field that showed no symptoms prior to harvest could shed needles after harvest either on the retail lot or in the home. Dr Hinesley and Dr. Shelton conducted unpublished research that suggested this was the case.

The third root cause of total needle loss that I have seen was Phytophthora root rot (PRR). Usually, Fraser firs that die of PRR hold on to their needles a long time, but sometimes in the fall when the diseased trees have been stressed, green trees will shed out just like they do with a calcium deficiency. Only healthy roots can actively take in calcium, so it makes sense that PRR can contribute to the expression of calcium deficiency.

In all of this there are few proactive steps to take. In terms of the imediate harvest, buy a shaker machine to remove interior needles on trees that are still salable. For the future, take a soil sample and fertilize your farm according to the reports. Don't let market trees go to harvest short on calcium.

Fall Needle Shed

2010-10-25T19:33:00.000-04:00

I'm getting out of my comfort zone talking about fall needle shed. I don't think we have a good explanation as to why it is happening. It is certainly associated with stress and is worse in some years (like this one) and in some fields than others.

Of course some needle shed occurs every fall. Usually it's the 4th or 5th year needles. The problem occurs when it's the 3rd, 2nd or even the current year's needles. That's when tags start coming out of trees!

These photos are ones I took with Jerry Moody on Friday at a high elevation farm in Avery County. The site was above 4,000 feet, and it was very windy -- that means a stressful site. Though these pictures were taken in Avery, I've heard of a lot more problems in Ashe County where it has been drier this summer and fall.

This tree had only a few areas that had discolored needles.

This tree had excessive shed throughout the whole canopy. It was a very heavy density tree, so it was hard to see from the outside, but it will still impact if this tree can be sold this year.

In some instances we've seen trees like this with current year needle drop that were due to root injury. Fertilizer burn can be one cause of root injury, but this particular field had not had any fertilizer applied since the spring. The shoots of this tree appeared to be healthy, as did the buds for next year. Root loss can also be caused by drought. Fraser fir, being a seed-run crop, will have individual trees that are more susceptible to drought than others.

I've had some calls from growers that are concerned that scales are causing this discoloration. At this site, there were no scales. If in doubt, look at the shoots of several trees. Turn the foliage over to look for the presence of scales. Most of the fall needle problems have not been associated with scales.

Advice for the grower? Keep on top of your fertility. By fertilizing according to soil sample results, hopefully you can avoid many of these problems. If the problem develops, take soil samples and plant tissue samples of healthy verses trees with shedding needles. And get your County Extension Agent involved.

Trapping Laries

2010-10-25T16:20:00.000-04:00

That's Laricobius beetles for the uninitiated. And yes, this is a Fraser fir blog, but every once in awhile I like to put something in about other conifer pests like hemlock woolly adelgid (HWA).

One of the predators being released for HWA is Laricobius nigrinus. Last week I went out with Jim Hamilton, Watauga County Director, and Bill Sweeney with the Bent Creek Experiment Station, to learn how to trap for these beetles.

Sweeney is looking at the traps every week to see if any Lari beetles are coming up out of the ground to feed on HWA. These beetles pupate in the duff under the trees. This first trap is a bucket placed over the ground with bait at the top (infested hemlock branches) where the beetles, if they were present, would congregate.

Each week he puts in fresh shoots in the container at the top. When the week-old shoots are removed from the trap, the foliage is beaten over a sheet to look for beetles. This photo shows Bill and Jim looking for beetles.

A second trap is placed around the hemlock trunk so that any beetles moving up the tree will be captured.

Unfortunately, we didn't find any Laricobius last Wednesday when we looked in Valle Crucis. I don't know if Bill found any at his other locations.

These beetles were released at Hemlock Hill behind Lees-McRae College in Banner Elk. Jerry Moody, the County Extension Director in Avery County, and I looked at these hemlocks on Friday. It had been a long time since I had been there.

Sadly, most of these huge trees have died. Here Jerry stands beside a dead giant. We also took some beats from younger hemlocks that are still alive, but we didn't find any Lari beetles.

HWA is having a sad impact on our forest hemlocks. Each time we have droughty conditions, it seems like more hemlocks die.

On a brighter note, Jerry and I visited a site where we had treated hemlocks with a trunk spray of either Safari or Merit + Pentrabark. The Safari treated trees at the low rate of 12 oz/gallon had only dead adelgids. We only took a quick sample of Friday, but the results were very encouraging. We'll make additional observations this spring.

Movento Gets Relabeled

2010-10-19T15:30:00.000-04:00

According to an October 18, 2010 press release from Bayer CropScience, Movento insecticide has received EPA registration for a second time. The original registration of Movento was cancelled because of administrative errors committed by EPA during its initial review and approval of the active ingredient, spirotetramat, in 2008.

I have been working with this systemic material for the control of many pests of Fraser fir including balsam twig aphid, balsam woolly adelgid, elongate hemlock scale, and mites. I have been interested in Movento because it is systemic, has the potential to control a wide variety of pests, and is less toxic than many pesticides used on Christmas trees.

When I work with new products, I like to conduct my own spray trials where I can closely determine initial pest levels and really see how well the product is working. But I also like to get the product into the hands of growers to see how well it works in real farm situations. With the issues with the labeling of Movento, I haven't been able to work as much with the product as I would have liked. This ruling by EPA clears the way for more complete evaluations.

Updates on Website

2010-10-04T15:24:00.000-04:00

As seen from some recent letters to the editors of the High Country Press, the public continues to be concerned about the production of Christmas trees in the area. Also, as we get nearer to Christmas, the media including blogs and other social media question the environmental safety of real Christmas trees. Because of this, I have revised the information on the web site, "Frequently Asked Questions about Christmas Trees and the Environment." This web site is found at: http://www.ces.ncsu.edu/fletcher/programs/xmas/environment/index.html

The updated information reflects new pest control practices, updated cancer rates for mountain counties, and newly available links. The site can be used as an overview for concerned citizens or references for reporters.

If you have any questions, comments, see any errors or have additional information that should be added, let me know.

Time for Annual Bashing of Christmas Trees

2010-10-01T19:54:00.000-04:00

It's October -- time for Halloween, Christmas decorations to pop up in stores, and the annual bashing of real Christmas trees. Thought I'd share the following that I sent in to a blog connected with artificial trees praising them as the environmental choice.

"...there is no reason why the joy associated with the Christmas evergreen may not be a means of arousing in the minds of children an appreciation of the beauty and usefulness of trees; and keen appreciation of the beauty and usefulness of trees is a long step toward the will to plant and care for them (Arthur Sowder, US Forest Service, 1949)."

A Christmas tree is a celebration of life -- renewed life in the dead of winter -- renewed life because of the birth of a Savior. How can that be celebrated with a big plastic brush? Because that's all an artificial tree is no matter how lifelike. It's not a tree. It never provided a perch for a butterfly or protection for a bird from a summer storm. It was never brushed by a deer or bear as they walked by. It never felt the pull of the sun to make it break bud and grow. It was never alive as a real tree was.

So what if you cut it down? Another will be planted in its place. That's the circle of life, after all. If people really wanted to be environmentally conscious at Christmas there would be no lights, no presents, no feasts, no visits to family. Cutting down one tree at Christmas is nothing compared to the trees cut down to supply an average home's paper needs for the year. But a real tree becomes part of the family if only for a few weeks. And after the season is over, it can be recycled into mulch to provide protection to new plants in the spring.

Don't we have enough plastic from China already in our lives? Shouldn't a really great Christmas have a real tree?

So yes, Virginia. It's OK to use a real tree to wait for Santa on Christmas Eve. It will make the Jolly Old Elf smile to himself to think that not all the traditions of yesteryear have not been forgotten.

A Word About Spray Suits

2010-09-27T11:41:00.001-04:00

Lots of folks wear the basic disposable Tyvek coveralls when applying pesticides. These state that they are not water proof, yet lots of folks use them when applying not just dry pesticide formulations, but wet formulations and even high pressure sprayers.

On Friday, Jerry Moody and I applied some materials for fall control of algae. We don't think they will work, but we wanted to be sure. One thing that some growers are doing is spraying bleach on trees to clean them up. We tried that last year, but with a backpack mistblower. This year we tried it with a high pressure sprayer to see if that will work any better since it didn't work at all last year. I sprayed a 3% solution of bleach on about 30 large trees with a high pressure sprayer, doing a thorough job of coverage. I wore a white tyvek suit.

Well, look at my shirt at the end of the job. My purple shirt was bleached where the zipper on the Tyvek suit was. If it had been a pesticide, I would not have been protected from it.

Take home message? When spraying with a high pressure sprayer, you need something water proof.

We'll let you know in a couple of weeks what kind of algae control we got.

(And I liked that shirt too!)

Cryptomeria Scale Found in Ashe County

2010-09-01T21:09:00.001-04:00

A small field of trees in West Jefferson has what I think is Cryptomeria scale. I had samples sent to the Plant Disease and Insect Clinic in Raleigh to confirm it, but it definitely looks like the same thing we saw in Macon County earlier this summer.

There are several differences between Cryptomeria scale and elongate hemlock scale. First of all, there are more symptoms of yellow blotches on the needles. Most of the trees with Cryptomeria scale have these symptoms, whereas most trees with EHS have no yellow discoloration.

A close-up of the foliage shows the striking symptoms. Note how it is worse at the lower part of the shoot where more scales have settled.

The scales look quite different from EHS. The newest growth appears to have mostly nymphs or younger scales. They look almost like yellow dimples on the needles. They also reminded me of eggs cooked sunny side up with really big yolks!

Under the microscope you can see that even the young scales hide themselves under the cuticle on the needle, giving them protection, and making them harder to see. I guess that's what gives the appearance of a big yolk with a bit a white around it when seen through a hand lens. There are also some more mature scales in this shot at the top. They look bigger of course.

On the older growth, the scales seem to grow on top of each other. There are more mature scales. They look sort of round, and many look brownish, but those, I think have already died. The healthy scales are yellow when you look at them under the microscope.

Many of these scales have been fed on by the twice stabbed lady beetles. These were everywhere on the trees, just like they were in Macon County. They left holes in the scales.

The adult lady beetles feed on the scales as well as the larvae.

Here are some lady beetle larvae. There are so many larvae, they almost look like they are feeding on and damaging the trees. But they are feeding on the scales. However, there are so many scales, they don't destroy them all. I looked at some needles under the microscope where the lady beetles had obviously been feeding, and there were live scales with eggs still underneath dead scales which had been fed on.

Here are two adults with eggs and some crawlers. It was hard to get a good picture of the crawlers as they were moving around a lot. But basically, crawlers all look about alike.

A scale that hasn't yet produced eggs was flipped over for this photo. The thin coppery line going from the middle of the scale is the feeding tube. You can see it best against the green of the needle at the top and middle of the scale.

These trees really went down hill over the last month. The grower didn't notice anything wrong with his trees until recently. In fact they thought that it was worse today than it was just last week. And in reports from other states indicate that the scale builds up and spreads very quickly. Its also been very dry in Jefferson this summer which I'm sure helped the symptoms be worse.

These trees are in a residential area with houses all around. As with the other site in Macon County, the best explanation as to why Cryptomeria scale showed up is because someone purchased nursery plants from up north where this scale is much more common, and they moved into the Frasers. Cryptomeria scale feeds on many types of conifers, but it certainly seems to like Fraser fir.

The grower is going to spray these trees within a week with Dimethoate, Asana and Safari. Before spraying, they will cut out and destroy the worst trees. In fact, it would take at least a couple of years of good growth to cover up heavily damaged. trees. I thought it best to add the Safari on an experimental basis as research from other states indicates that Safari works well.

It's getting a bit late in the season to control these scales, but hopefully they will get some control. I'll assess them after a month to see how well the treatment worked and probably again in the spring. If need be, the grower plans to treat again in the spring.

Are there more sites with Cryptomeria scale in western North Carolina? It is certainly possible. Most growers now know what EHS looks like, but they could easily mistake this scale for EHS. It does look different, however. It is more rounded that elongated. There are also no white males, and no white waxy discoloration on the top of the needles. Another tell-tale sign are all the twice stabbed lady beetles which appear to be very characteristic of this scale.

This scale is much worse than EHS. It appears that it spreads faster, and it definitely has a greater effect on the tree. We have yet to see if it is just as hard or even harder to control. According to reports from Pennsylvania and Connecticut, control of both scales is similar.

If anyone thinks they have Cryptomeria scale, please let me know and I'll come out and look at it. Everyone needs to keep an eye out for this pest, so we can track if it is spreading.

Algae Control Results

2010-08-27T14:20:00.001-04:00

Several people have been concerned about algae again this year. However, I don't think the algae has been as bad this year as last year. In the two fields where we treated, there was definitely more of it on the 2008 growth than the 2009. We had a hot, dry spell in the summer that no doubt reduced the development of algae, but there are still problems. (Photo was taken by Bryan Davis last year showing extreme discoloration in 2009. Note that the current year's needles are not affected).

The first thing to realize when looking at algae control is that the best you can do is prevent more algae from developing. It's hard to cure algae once it's already there. It develops primarily on last year's foliage -- not this year's. It appears that it comes in the June time-frame. Therefore in these spray trials, we were looking at algae development on last year's growth -- that is 2009 growth. For the most part, we didn't do anything to reduce discoloration on 2008 growth (which developed the summer of 2009) or earlier. Still, if you can go to market with 2 years of good green color, it should be good enough.

This photo was taken under a microscope showing some algae on the needles. It is easy to see with a hand lens. It is also easy to wipe off the surface of the needle.

We applied different materials for algae control this spring before bud break at 2 sites -- one in Mitchell and one in Avery. Thanks to Jeff Vance and Jerry Moody for help in finding locations to work in and spraying the materials.

All applications were made with a backpack mistblower. At both sites, an untreated row was left between each treated row to reduce cross contamination of treatments.

At the Mitchell County site, treatments were made on rows of 10 trees. There were 3 replications. Applications were made on April 29 using one of the following materials:

Kocide 3000 at 3.5 pound per acre. This is a copper based material which is made up of 30% copper. Kocide label.
Dithane at 1.5 pounds per acre. The active ingredient of Dithane is mancozeb. Some Jackson county growers were seeing some control of algae in the fall when this material was applied. However last year, I didn't see very good results from this. Review of last year's work.
Daconil at 3 pints per acre. The active ingredient of daconil is chlorothalonil.

In Avery County we didn't replicate, but instead treated a long row with 30 or more trees. Original treatments were made on May 5 using either Kocide, Dithane or Daconil at the treatment rates described above. Addition treatments were as follows:

Cosan, an organic disinfectant, at 2 teaspoons per gallon
SA-20 disinfectant at 2 teaspoons per gallon. This product is made of 10% dimethyl benzylammonium chloride and 10% dimethyl ethybenzyl ammonium chloride. It is used to disinfect pots, greenhouse areas and tools.
Kocide applied twice -- on May 5 and again on May 19
Kocide applied once on May 19

Jerry, Doug Hundley and I looked at the Avery County treatments yesterday, and Jeff Vance and I looked at the Mitchell County treatments this morning.

There appeared to be more algae developed at the Avery than the Mitchell County site. This surprised me as the Mitchell County site was much worse last year. (This photo, taken in Mitchell County, shows a shoot from an untreated tree with algae on last year's growth).

All treatments appeared to have some effect on the algae. The Dithane and Daconil didn't work as well as the other products. Kocide appeared to work best. Applying it twice seemed to work a bit better, and applying it later in May also seemed to work some better.

This photo is of a shoot from a treated tree. Note that there is no discoloration on 2010 or 2009 growth. If the treatment hadn't worked, you would see discoloration on 2009 growth. The material didn't reduce the discoloration already present on 2008 growth.

This is typical of any fungicide. They prevent disease from developing. They don't cure disease. Therefore a successful treatment will keep algae from developing the year it is applied. But that's similar to all of our pests. When you treat for twig aphids or spider mites, you don't do away with the damage you already have. Instead you cover it up with new, undamaged foliage.

I would like to repeat this next year, applying materials with either a high pressure sprayer or backpack mistblower. I suspect that the high pressure sprayer will give better control, but that most growers will prefer the speed of the mistblower. I also hope to try out some Kocide this fall to see if it will help "cure" some of the algae. I don't think it will, but since I didn't try it last year, I want to make sure.

Take home message: It looks as if Kocide and perhaps some other materials will reduce and in some instances prevent algae from developing when applied in the spring. In fields where algae development is expected because of woods or the trees are growing close together, a preventative treatment is required starting the year before sale and continuing until all the trees are harvested.

A big thanks goes to Kelly Ivors and Gary Chastagner for their help in identifying possible treatment windows and materials.

Some HWA Pics

2010-08-26T19:58:00.001-04:00

OK, I know this is a Fraser fir IPM blog. But I work some with HWA on hemlocks and can't help but post a few things about that too.

Five years ago, I took some photos of hemlocks in the Linville area. Today I went back and visited some of those trees. Mostly the hedges looked really good. But many of the trees that I know had been treated are now gone. Others don't look much better.

Here are the pictures:

This picture was taken five years ago.

This is the same tree five years later. It is still hanging on, but doesn't look much better.

This tree is no longer there. It had been treated with Merit, but didn't seem to be doing too well five years ago when this picture was taken.

These trees are in the same yard as the previous picture. They don't look that good either, but are at least still alive. The hedge, however, looks great.

My last photo is dead hemlocks along the Parkway.

2010 Growth in Organic Demonstration.

2010-08-24T21:07:00.001-04:00

Today I measured the terminal growth on the 183 trees I've been evaluating at the organic demonstration in Alleghany County. Thanks again to Della and all the Deals and Tuckers for all their help with this study.

A big thanks also goes to Bryan Davis who has been keeping the site going. For the 3rd NCTA farm tour on August 14, Bryan dug up three trees from this demonstration so that folks could see how the trees were doing. One was a typical "late organic." Remember that these are the trees that are being grown conventionally until the last 3 years before harvest when they will go totally organic -- that is, they are "going organic" late in the rotation with just enough time to be certified as organic. He also brought 2 trees from the organic portion -- one that was growing poorly and one that was growing well.

Those trees were strikingly different. The poor organic tree was just barely alive. The good growing organic tree was growing well, until you compared it to the typical "late organic" tree which was taller and fuller.

The numbers I collected today with the help of my daughter (in the rain no less) bare this out. I measured the terminal of the trees and also gave the trees a rating based on how well they were growing. Trees were given a rating of "1" if they were barely growing at all. A "2" rating was given to a tree that was growing better, but still had poor color and bud set. A "3" rating was given to a tree that was growing acceptably. A "4" rating was given to an exception tree both in color, bud set, needle length and fullness. Of course these ratings were completely subjective and sometimes I had trouble deciding between a "2" and a "3" or a "3" and a "4."

Here is a summary of the data. The "late organic" trees are more likely to have a rating of 3 or 4. Their terminal growth is on average 4.6 inches longer, and there is a higher percentage of trees with at least 12 inch terminals.

There are some very nice looking organic trees. There just aren't as many as in the other section. Still, all the trees are growing better than they did last year. Last year the average terminal growth for the entire study was 6.1 inches. This year it was 14.0 inches -- more than twice as much. The trees that suffered severe drought when they were planted in 2008 with a southern exposure are finally growing strong.

NCTA Meeting

2010-08-11T09:55:00.001-04:00

Hope everyone can come to the National Christmas Tree Association annual meeting in Winston this week.

I will be speaking on Friday morning. My talk is called, "Getting Personal With Pests." We have it on-line if you'd like to look at it. It is found at: http://www.ces.ncsu.edu/fletcher/programs/xmas/production-mountains/Sidebottom-Pests_2010-08-13.pdf

It's kind of a big file, so it will take awhile to pull up.

I'll also be on two of the farm tours. I'll be speaking on Saturday morning at Harry Yates' farm on elongate hemlock scale. Then in the afternoon I'll be speaking at Omni farm on scouting, pest control and our organic demonstration.

Some Scale Control Results

2010-07-28T11:43:00.001-04:00

On June 20th I posted about a spray trial I had applied that day with 4 different materials for control of scale. Meghan Baker helped me collect samples from that study on July 27 and I looked at the results.

The following numbers are the percentage of dead scales based on observing at least 100 scales:
Check -- 53% dead
Movento + Liberate -- 69% dead
Lorsban -- 75% dead
Safari -- 83% dead
Dimethoate + Asana -- 84% dead.

Remember that these were applied with a backpack mistblower which never does give as good results as with a high pressure sprayer. Hopefully with a bit more forceful coverage you would be getting closer to 95% control with the Dimethoate +Asana.

The Lorsban results were a bit disappointing. I was hoping control would be better. Safari worked well. I've seen situations when it hasn't worked as well, but there has been plenty of rainfall in that area which probably helped it get in the plant better.

I will re-evaluate control in these trees in the fall to see if any clearer differences emerge. I will also apply these same materials to other trees in September to look further at fall scale control as well as twig aphid control the following spring.

Japanese Beetles

2010-07-23T11:32:00.001-04:00

I may not be moving about too well these days, but thankfully others are out in the trees seeing what's going on.

Jeff Owen has told me that he is seeing Japanese beetles on the terminals feeding. He's seeing this in several tree fields to a greater extent than most years.

Japanese beetles are just one of a number of terminal feeders. They tend to feed toward the top of the tree and terminal, creating irregular patches, though in this picture which I took years ago, they are feeding on older growth. Their feeding is swallow, but will result in discoloration and sap flowing.

Usually by the time you notice the feeding, they have done as much damage as they are going to do. They aren't anything to worry about. However, if you are seeing the insects in your trees, you can spot treat with any good insecticide. A backpack mistbower or backpack sprayer is sufficient. When using a backpack sprayer, I like a hollow cone nozzle for applying insecticides.

Some Interesting Pictures

2010-07-13T10:11:00.001-04:00

I'm sitting at the extension office with my leg propped up after knee surgery. Walking in all these tree fields sure tears up your knees! It will be awhile before I can tromp around again, so I thought I would post some pictures I've been working on while laid up.

The first is a picture I took at Ewing Harmon's on June 29th. He had treated his trees for scale, and it looked like he got good control. This photo shows what folks need to look for after treatment. There aren't any nymphs on the new growth. I hope you can see in this picture that the needles on the newest growth are scale free.

Scales have moved onto 2010 growth, so if you look at fields and aren't seeing the scales on new growth, that's a good sign. Also, it's easy to see the fuzz from the male scales back in the canopy now. If there aren't many of those, that shows good control as well.

I had commented in my June 30 post about the spread of scale at Dale Cornett's field in Watauga County. I made a colorized scheme to show the increase in scale at Dale's which I have photographed below.

I think this is interesting for a couple of reasons. First of all, the most heavily infested trees in 2010 are scattered everywhere, they aren't just concentrated where the most heavily infested trees were in 2008 which was on the far end of the field.

Something else that was interesting was that two years ago, Dale had some trees with heavy incidence of pine needle scale, not just elongate hemlock scale. We didn't find any of those this year. That's good, because we don't need any other major scale problems.

To date, Dale has only used Di-Syston for pest control in these trees.

The annual Watauga County Christmas Tree Grower's Association meeting will be July 29. I hope to go out before that meeting and look at scale control in the plots that I treated before that meeting, and will report at the meeting and in this blog what I find..

The last schematic I will post today depicts IPM in Christmas trees. I created this for the National Christmas Tree Meeting in Winston Salem in August. This Christmas Tree IPM Pyramid shows the importance of a good IPM foundation to ultimately be successful with pest control.

And this is what so many tree growers in North Carolina do. They work hard to get good fertility and ground cover management, then scout to determine what pests they do have. Through this process, their pesticide controls have been more successful. In fact, I haven't heard of anyone that is too upset that Thionex will be taken off the market. They don't need such a strong material. They can get excellent control with safer products.

Anyway, hope everyone enjoys these schematics. Feel free to use them however you can.

Doug's Color Wheel

2010-07-01T14:30:00.001-04:00

Doug Hundley was telling me the other day that he was explaining to a newer grower all the different times of year you could control the different Fraser fir pests. It's amazing how much our knowledge of pest control has changed even over the past few years. When treating for one pest, you can target others that you have as well, either by your choice of pesticides or how thoroughly you spray.

He told me that he took the white paper plate he and the grower were beating pests on, and he drew different color circles to represent the times of year you could control different pests. I thought it was a great idea. So I put together this color wheel. I haven't talked to Doug or others yet to see if my circles correspond to theirs, so let's talk about it. Email me your comments. I can change it however folks see fit.

A Good Day for Scales to Die!

2010-06-30T15:15:00.001-04:00

At least I hope so!

Today I sprayed 4 different materials for EHS control. I applied the materials with a backpack mistblower, using about 100 gallons to the acre. I treated 40 trees each with either:

Safari @ 8 oz/100 gallons
Movento @ 10 oz/acre + Liberate (an adjuvant) @ 2 pts/100 gallons
Lorsban @ 1 qt/acre
Dimethoate @ 16 oz/100 gallons + Asana @ 10 oz/100 gallons

The population was ready for control. I collected a sample and looked at the percentage of individuals that were either males (the easiest to kill), nymphs, or females (the hardest to kill). Only 14% of the population were females with 24% as males and 62% as nymphs. I'll come back in a month or so to see what kind of controls I got.

The field I treated was part of a study to see how quickly the scales spread. On July 14, 2008, Bryan Davis and I evaluated 361 trees to see which ones had scales. We flagged infested trees and made a map. At that time, about 1/2 of the trees had scale, though most of it was only a shoot. Only 4% of the trees had moderately heavy scale.

We couldn't go back last year because the grower had put lime on the trees, and it was too hard to tell what was lime and what was scale. But I went back yesterday before treating today.

Now 95% of the trees have scale and 40% have it pretty bad. But even on trees that have had scale heavy for two years or more, they don't look that bad (one is pictured at the end of this blog along with a photo of the field). I do think the trees that have had scale heavy have weaker bottoms, but they are still growing well.

So how much does EHS really damage trees? The jury is still out. I think we can keep the scale "beat back" though never eliminating it completely. For most growers who aren't shipping to California or another country, that will probably be good enough.

Some Success with Safari

2010-06-28T15:17:00.001-04:00

On January 25 in this blog, I reported some success with controlling balsam woolly adelgid (BWA) with Safari (dinotefuran). Safari is a neonictinoidal insecticide similar to Merit (imidacloprid), but far more water soluble. Safari also controls elongate hemlock scale.

Spring treatment. This spring, Buddy Deal sprayed some trees with Safari + Dimethoate. Remember that Safari doesn't control twig aphids or mites, so the Dimethoate was for twig control. They used a high pressure sprayer, but put out the materials with a light spray intended for twig control and not for woolly control. They didn't soak the trees or the trunks. The rate was the high rate of 8 ounces per 100 gallons which is the high rate. The field is pictured here.

We went back about a month later, on May 20, and the woollies were still alive. But it had been rather dry, and we decided to go back in another month.

On Friday June 25, Bryan and I went back again. This time the woollies were all dead -- both on the trunk of the tree and on the buds and branches. We didn't find any live adelgids at all.

I'll keep an eye on these trees over the next 12 to 18 months to see if the woollies come back quickly or if the control is long lasting.

Seed orchard treatments. We've been putting out Safari for BWA control in seed orchard trees as well. On June 17, we treated trees at the Mount Rogers seed orchard at Grayson Highlands State Park in Virginia. This will be on one of the summer tours for the NCTA/NCCTA meeting in August.

We treated 3 trees with one of 5 treatments:

Safari soil drench at the high rate of 4.2 oz/10 inches trunk diameter
Safari soil drench at the low rate of 1.0 oz/10 inches trunk diameter
Safari trunk spray at the high rate of 24 oz/gallon
Safari trunk spray at the low rate of 12 oz/gallon
Merit soil drench at the highish rate.

The trunk sprays are interesting. The material soaks up through the bark and travels through the tree. I sprayed with a backpack sprayer using a hollow cone nozzle. I sprayed from 5 foot high on the trunk down to the root flairs, wetting the entire trunk, but not to runoff. If the low rate works (the high rate would be way too expensive), it would be a quick easy way to control woollies in seed orchards or very large trees (greater than 12 foot). I will check the control before the NCTA meeting.

HWA treatments with Safari. Jerry Moody and I also treated hemlocks with these trunk sprays using either Safari or Merit. In this case we also added Pentrabark to increase penetration through the bark.

Elongate hemlock scale control. I also plan on treating some trees for elongate hemlock scale later this week. I'll compare the Safari to Dimethoate + Asana, Lorsban, and Movento.

I'll keep everyone posted of how well things work.

Some June Pests

2010-06-28T15:01:00.001-04:00

Went out last week and found several June pests that might be of interest to folks.

Elongate hemlock scale. Scales are making their way onto the new growth. If you treated this year in the spring, or sometime last year, and you aren't seeing the scales get on 2010 growth, that means you have pretty good control. This is a photo of scales on 2010 growth.

At this particular field, the grower had treated with Asana + Dimethoate with his mistblower before bud break this spring. Though there was still live scale, it hadn't spread to new trees, so we counted the treatment as a success, since it was far less expensive than spraying with a high pressure sprayer. The grower was going to cut out the worst trees for scale (he'd have a hard time selling them anyway), and will retreat in a few days with his mistblower while the crawler number is at its peak. Hopefully that may also give him twig aphid control next year.

Balsam woolly adelgid. Woolies have also moved onto the 2010 growth. This photo is of nymphs already on the new growth. There is already swelling too. These will molt in place to the adult within the next month and start laying more eggs.

This particular block of trees had been treated with dimethoate in the spring. No control of woollies. The grower will spray with Talstar sometime this fall.

White pine cone beetle. The pine cone beetle is an infrequent pest of Fraser fir, borrowing into usually the first whirl of branches and making a shepherd's crook. Sometimes you can still find the black beetle in the tree. The two photos are of the entrance hole and then of the beetle. These pictures were taken in Ashe County last Friday. I haven't seen any of these pests for several years. They are usually only a problem when there aren't many white pine cones, which are their preferred food. When you find them, they have already caused as much damage as they are going to, so they are only a novelty and nothing to worry about. Shearing will take care of the problem. Bryan found these. Jerry Washington was the first one to find them years ago.

Leaf footed seed bug. The last interesting bug Bryan also found on a Fraser fir cone in some Christmas trees. I think it is a leaf footed seed bug that will feed on Fraser fir cones. You never know what you'll find in a tree field!

Spider Mites

2010-06-22T15:43:00.001-04:00

Bryan Davis was telling me that he's seeing several fields where spider mites are becoming a problem. One of the fields we had scouted thoroughly in April without finding any mites. I've also seen some spider mite activity in a couple of fields. Though it's been wet and humid, it's also been rather warm (understatement, yes I know!) which makes mites more active. So if you haven't had a chance, now would be a good time to look for spider mites before the shearing season swings into gear and they end up causing damage.

Cryptomeria Scale

2010-06-21T10:59:00.001-04:00

Cryptomeria scale (Aspidiotus cryptomeriae) has been a problem on Christmas trees for several years in Pennsylvania and other states, but not in NC until now. Alan Durden found some on Fraser fir in Macon County, which I had the opportunity to visit last week.

The trees were from 4 to close to 12 foot tall, not far out of Franklin. There was a very heavy incidence, but many of the scales didn't look healthy. Some had fungi growing on them. Others appeared to have been feed upon.

For those of you familiar with elongate hemlock scale, the life cycles and control of these two scales are quite similar. The biggest difference is that the cryptomeria scale is more rounded in shape. We found nymphs on the new growth on some of the trees.

We also found a lot of the twice-stabbed lady beetles (genus Chilocorus) -- both adults and nymphs. Richard Cowles and others reports that these are good predators for scales. I have never seen them feeding on elongate hemlock scale, and in fact usually only see about one a year, but there were dozens on these trees.

Because of the predators and because the grower only has a few trees, we decided to wait a month before deciding what to do for control.

Symptoms on the top of the foliage are similar to elongate hemlock scale. They aren't found on all the infested trees just like with EHS. I didn't see any of the white fluff that gets on trees with EHS. That probably doesn't occur.

This is what the scale looks like under the foliage. For a clearer picture, google the scale.

Here is one of the lady beetles. They are real pretty.

Update on Endosulfan

2010-06-15T10:33:00.001-04:00

Wayne Buhler, the pesticide coordinator for NCSU sent the following message out this morning. It is from Lee Davis with NCDA&CS about the fate of endosulfan. Nothing has been decided yet about how the product will be phased out, but Lee describes what usually happens. Again, when things have been decided, I'll let you know.

"Yes. The way I understand it is that the EPA and the registrant are currently working out the details of how to cancel the product. Usually, the EPA will post to the Federal Register a notice to cancel the product and give a date upon which the product is cancelled. Usually, the EPA will allow product already in the channels of trade or in the hands of the end user to be used up according to label directions. This is what usually happens, but each cancellation notice is unique. So, it is not possible to say exactly what instructions might be in the cancellation notice.

Thanks,

Lee"

Endosulfan (Thionex)

2010-06-11T13:38:00.000-04:00

As of June, 2010, EPA has decided that endosulfan, the active ingredient to Thionex, poses too great a risk to workers and wildlife. Therefore EPA is taking action to end all uses of the product. You can read more about it at: http://www.epa.gov/pesticides/reregistration/endosulfan/endosulfan-cancl-fs.html.

According to an EPA news release dated 6/9/2010, "Makhteshim Agan of North America, the manufacturer of endosulfan, is in discussions with EPA to voluntarily terminate all endosulfan uses. EPA is currently working out the details of the decision that will eliminate all endosulfan uses, while incorporating consideration of the needs for growers to timely move to lower-risk pest control practices."

I do not know anything more at this time, but will keep you posted.

Another Scale

2010-06-07T10:53:00.001-04:00

In one Christmas tree field near Jefferson, Bryan Davis kept seeing a different kind of scale. We finally sent them in, and they were identified as the hemlock scale (Abgrallaspis ithacae). This scale is native to the US. It is closer to target shaped instead of elongate. It is not reported as being damaging to trees. The following image is from IPM Images. We will be monitoring this site to see if these scales develop into a problem.

Respirators

2010-06-03T16:44:00.001-04:00

As more research is being done on the chronic effects of low level exposures to pesticides, it continues to be apparent that pesticide use can adversely affect the health of the pesticide applicator. That's why it's important that people wear the appropriate personal protective equipment, and even use more PPE than is required, especially when treating Christmas trees with a high pressure sprayer.

One of these pieces of equipment is the respirator. In my opinion, anyone treating trees with a high pressure sprayer should use a respirator. This is true whether you are using horticultural oil or a synthetic pesticide. Few materials require the use of a respirator on the label, but since you are continually walking through the spray, that is the best way to reduce exposure.

Some of the commercial applicators have purchased the helmets with motorized forced air which completely cover the head. These offer the most protection, and are the easiest to wear. They keep the worker cool, and don't require a lot of effort to breath through them.

But a lot of people still depend on either the full or 1/2 face respirator with attached cartridges which are certainly less expensive. However, there are several issues with these.

1. They don't cover the entire face, and in fact the ear canal is one area of skin that is particularly thin and will readily absorb pesticides. The rate of absorption is far higher than the skin on your palm or forearm. Using a hood on a spray suit will eliminate this problem.

2. Many people don't fit the respirator closely enough to the face. I've seen several folks wear respirators that just hang on their face. The respirator is supposed to fit snugly so that all air breathed in passes through the cartridges. And yes, when you do this, they will fog up. But, when the fit isn't snug, contaminated air can come in through the sides. If a man has a beard or mustache, this can interfere with the fit. In fact, it is best not to have facial hair when using a respirator.

3. The third issue then becomes one of applicator's health. Some people's lungs just aren't strong enough to pull air through the respirators.We all know how tiring it is to wear a hot spray suit and respirator and walk through trees spraying with a hose. You have to have good heart and lungs to be able to do this demanding work.

In fact, OSHA regulation 1910.134 requires workers be properly trained in using a respirator, that a fit test be conducted, and that the worker is certified by a doctor as being physically fit enough to use the respirator. These requirements have largely been overlooked in agricultural circles, but that may be changing.

So be safe. Check the fit on your respirator, and use it like it was intended.

HWA Control

2010-06-02T09:13:00.001-04:00

OK, I know this is a Fraser fir blog, but I had to include a photo of these hemlocks. They are at my office in Mills River. I treated them 2 years ago for hemlock woolly adelgid with Safari using a soil drench, and they are still growing like gangbusters. We'll be looking closer at Safari for the control of balsam woolly adelgid.

Update on Organic

2010-05-28T14:12:00.001-04:00

On February 1, I gave an update on the organic demonstration in Alleghany County. Since then, I've evaluated tree mortality over the past year. In all, only a handful of trees have died -- the same amount in both the organic and "late organic" sections. (Remember that the "late organic" trees are being grown with conventional use of fertilizers and Roundup, then switching to organic practices in 2011).

The trees are all growing now, and Bryan and I made some additional observations just last week. The following are some of our observations.

This photo was taken last week. Bryan had weed eat (is that a verb?) about half of the organic section. The organic trees vary quite a bit in quality. Some trees look great -- growing just as well as those in the "late organic" which is very encouraging. Others look, well, rather puny. Some of these are clear in this picture. The "late organic" trees are at the bottom of the field (top of the photo) and are much more uniform -- except where the deer got them!

By and large the major ground cover around the organic trees is grass. That's what Bryan is chopping down, and it took him more than 2 hour to finish just 1/4 acre. We figure it will need to be mowed again in mid-summer with a clean-up in the fall. We might also have to come in when problem weeds such as spotted knapweed are flowering to keep them from going to seed. We're also considering going back in and removing the chopped weeds from the ground cloth around each seedlings so it won't decompose and provide a site for weeds to germinate. All in all, an acre of organic trees will end up costing quite a bit in labor for weed control.

The other issue with using a weed eater? Injury. To the right is one of the trees that bit the dust. Bryan is afraid that every time someone does this, as least 1 or 2 trees will be injured. Over the years, that will add up.

In the "late organic" there isn't nearly as much grass. There's lots of clover, and also lots of mustard blooming a bit earlier. However, there are also a lot of thistles which they tried to hit with the Roundup. Both areas still have quite a bit of poison ivy which a problem for me especially! So neither section is perfect when it comes to weed control, but that's farming!

End of May Explosions

2010-05-27T14:35:00.001-04:00

Rust Mites. Bryan Davis has seen in a few fields a real upsurge of rust mites in the last few weeks. With the cooler weather, and especially cool nights, rust mites are remaining active. Some of the fields that only had a few rust mites in them a month ago are getting damage now. So if you haven't been in your trees lately and the field is prone to rust mites, it might be a good idea to check and see if rust mite numbers have exploded.

Should these fields be treated now? That should be decided on an individual case basis. The weather should be warming up soon, but as long as the nights stay cool, rust mites will continue to be active. Only treat now if mite numbers and damage truly warrant it.

Twig Aphids. Also, there have been a few fields that weren't treated for twig aphids this spring because of fall treatments that twig aphid numbers seemed to explode in. A month ago, there weren't any twig aphids, but now there is some damage.

This spring allowed the few aphids that did survive a chance to quickly reproduce. However, with all the wet weather, the trees are growing so well that much of that needle curl will be grown out of. So it is nothing to treat for, but only to be aware of.

Algae Treatments

2010-05-19T14:30:00.001-04:00

Just got finished putting out materials for algae. There are 2 plots -- one in Avery and one in Mitchell. The initial treatments were made the first part of May. Today Jerry and I made a second treatment of the Kocide in one plot, and also treated some trees with the new growth out.

With all this rain and cool weather, I'm thinking that we might have a lot of algae in trees again this year! I'll keep everyone posted on the results, but it will probably be August before we know anything.

Spring Rush & Rosette Bud Mite Treatment

2010-05-11T12:31:00.001-04:00

Sometimes kids seem in such a hurry to grow up. It seems like that's the way it is with this spring! All at once, all the Fraser fir buds are breaking everywhere. Hope no one got any frost earlier this week.

I just wanted to remind folks that if you have to treat your trees for rosette bud mites, you might end up treating earlier this year than you usually do. You want to wait until ALL THE TREES in the block have broken bud. But theses late breakers, might be all out by the end of next week instead of into June. Let your trees be your guide.

A singe treatment of either Dimethoate or Mavrik will control the rosette bud mites. For more information see: Rosette Bud Mite on Fraser Fir -- CTN 018A.

Algea

2010-04-27T10:36:00.001-04:00

We had more growers with algea problems last year than ever before. We tried various products in the fall to get rid of the discoloration including Prev-Am, chlorox solutions, Dithane, horticultural oil, or zerotol. I even tried painting some trees. But nothing seemed to work.

That's when Kelly Ivors, our plant pathologist, talked with Gary Chastagner about it. They have been using copper based products in the spring out west to prevent algea from appearing.

So this week I hope to put out two studies looking at algea control -- one in Mitchell County with the help of Jeff Vance and one in Avery County with the help of Jerry Moody. We are going to be applying fungicides with a backpack sprayer. We'll treat some trees only once. Other's we'll retreat in about two weeks.

One of the products we're using is particularly recommended by Chastagner, called Kocide. The active ingredient is copper hydroxide. Kocide 3000 is labeled for fir trees in Christmas tree plantations to control needle casts at the rate of 0.75 to 1.75 pounds per acre and to control lichens at the rate of 3.5 pounds per acre. It should be applied before bud break.

I don't know yet if it will work, but it is a labeled product that you can try if you had a serious problem last year and think you'll have a problem again this year. I would only recommend this treatment in fields that are humid, such as those near woods, creeks, or where the trees are getting large and growing together. The label can be found at:http://www2.dupont.com/Production_Agriculture/en_US/label_msds_info/labels/SL-1344-2.pdf

Earth Day

2010-04-22T14:26:00.001-04:00

For Christmas tree growers, every day is Earth Day. Since I started working with Christmas trees in 1988, I've seen a complete transformation of the industry in North Carolina. Growers have slashed their pesticide and fertilizer needs through adoption of IPM practices and good ground cover management.

And look at the healthy Frasers on Mount Mitchell. I took this photo last year from the new tower. Given half a chance, nature has a wonderful ability to heal herself.

Getting Rates Right

2010-04-22T13:13:00.001-04:00

I don't think there's anything else that causes people more confusion than numbers. And unfortunately, pesticide rates are all about numbers.

Insecticides can be labeled as a per acre rate, or a per 100 gallons rate. Growers like the 100 gallon rates, because they are easy to mix, but often the per acre rates are more accurate.

When spraying with a mistblower, it's pretty easy to calibrate the sprayer. In fact, most growers can tell you exactly how much water they are putting out per acre. The problem comes when putting out sprays with a high pressure sprayer. Yet, when I start to question people, they can usually give me a ball park figure -- say less than 200 gallons per acre or around 300 gallons per acre or 500+ gallons per acre. And that's all you need to know to get an idea of how much chemical to add per 100 gallons.

For instance, if you are trying to apply Envidor at 24 ounces per acre, it you are using 300 gallons of water per acre, mixing the product at 8 ounces per 100 gallons will give you the exact rate. But if you are spraying 500 gallons of water per acre, you will be applying more than 40 ounces per acre which exceeds the rate and will cost way too much money. If you're using less than 200 gallons of water per acre, you'd best mix it at 12 ounces per 100 gallons. So before you mix, think about how much water you're likely to use. *(See below for calibrating a high pressure sprayer).

Using that same Envidor at 24 ounces per acre out of a mistblower? Applying 40 gallons of water per acre? Then you would mix the Envidor at 60 ounces in 100 gallons.

But what about when you are applying a materials with a mistblower that has a per 100 gallon rate? Asana is a good example of this. Labeled at 9.6 ounces per 100 gallons, it can be used in a mistblower to get control of multiple pests including twig aphids, balsam woolly adelgid, and elongate hemlock scale.

Back when I first started working, Bill Huxster and Jim McGraw encouraged people to use 3 times the per 100 gallon rate when spraying with a mistblower. That's because growers are using much less water, but they still need basically the same amount of chemical per acre. It turns out, that's a pretty good rule of thumb. A mix of 30 ounces of Asana per 100 gallons seems like a lot, but Asana is labeled at up to 52 ounces per 100 gallons in ultra-low volume sprays (such as an aircraft) and as much as 37 ounces per acre for certain pests in Christmas trees.

When looking at labels, see if there is a cap for application. Is there an amount you should not exceed when applying materials specified on the label? Use this as your guideline for how much to apply.

Figuring out rates when it comes to insecticides is just common sense. Take a minute to make sure what you're using makes sense.

*CALIBRATING A HIGH PRESSURE SPRAYER:You can always calibrate your high pressure sprayer. First determine how much water you are putting out per second. Spray into a bucket for 10 seconds having set up the gun the way you mean to spray, measure what you spray and divide by 10. (You might need to cover the bucket with a garbage bag to keep it from coming out). That gives you what you are spraying out per second. Then spray a few trees and see approximately how many seconds it takes to cover the tree the way you want to.

An example -- say you spray 3 ounces per second and approximately 4 seconds per tree on one side. Since you spray from two directions, thats 8 seconds per tree. That's 24 ounces of water per tree. If you have 1,700 trees per acre, you are using about 300 gallons per acre. If you stock at 2,200 trees per acre, you would be using about 400 gallons per acre.

Twig Aphids Reproducing

2010-04-16T15:13:00.001-04:00

Just wanted to let everyone know that I examined some shoots under the microscope today and found evidence that the twig aphids have matured enough to being reproducing. Remember that the form that hatches from the egg is called the stem mother. At maturity she lays live young. That is taking place now.

With this warm dry spring, twig aphids are surviving well and maturing quickly. There is a potential for damaging numbers to build up quickly now.

Role of Apollo

2010-04-15T10:15:00.001-04:00

Several folks have been talking about treating this spring with Apollo plus Dimethoate. Apollo is a miticide with similar activity to Savey. Those Apollo plus Dimethoate should give good control of twig aphids and spider mites, but only fair control of rust mites. After all Apollo, though an ovicide, has no activity against rust mites, just as Savey doesn't.

The kicker is, there are almost no spider mites anywhere. I've worked tree fields for several weeks, Bryan Davis has, and several other agents. Fields with spider mites are few and far between. I think I've seen a dozen spider mites eggs total in 3 weeks of scouting.

Rust mites, however, are being found frequently. A few fields have high rust mite numbers. Other just have maybe a mite per shoot. (Remember that the treatment threshold is 80% incidence and at least 8 mites per needle).

The mix of Apollo + Dimethoate will knock rust mites down (due to the Dimethoate), but since it is so early in the season, the mites may rebound. That is why in a situation where rust mites are plentiful now, Envidor is the better choice. It controls both spider mites and rust mites. Envidor plus Dimethoate should give excellent and full season control of twig aphids, rust mites and spider mites.

Scouting will determine which blocks should have the Envidor added, and which don't, as rust mites are not a problem in every farm or even on every block on a farm. Don't assume that just because you used either Asana or Talstar last fall that rust mites are a problem. They aren't. You don't know until you go out and look.

And scouting doesn't have to take a lot of time. When I go out with the county agent or technician, it always takes longer because we're talking about control options, showing the grower different pests and the like. But if I was just going out there to scout, it wouldn't take me long at all.

Envidor is only labeled to be applied once per year (as is Savey and I think Apollo as well). This is to reduce the likelihood of resistance. But chances are, spider mites won't develop and become a problem if you have good ground covers. Even during droughty years, we've seen very few farms with bad spider mites in recent years. Once again, a quick scout through should be able to identify problem sites.

So scout. Then chose what you need based on those scouting results.

Controlling elongate hemlock scale (and everything else too!)

2010-04-09T14:00:00.001-04:00

This is a picture of a Fraser fir heavily infested with elongate hemlock scale (EHS). We're starting to see more symptomatic trees like this in the area and frankly more problems with scales.

Bryan Davis and I have been working with a grower in Ashe County who treated multiple fields in 2009 with Dimethoate + Asana using a high pressure spraying for scale, starting June 26th and going all the way through September 7. Most of these fields had a very heavy incidence of scale.

What we're finding so far is that the fields treated in June and July and into the first 2 weeks of August had decent control -- mostly 90% or better. By later in August and into September, control really dropped off -- to about 70%.

Of the 8 or so fields we've looked at so far, all appear to have twig aphid control and only one had a heavy incidence of hemlock rust mites. The grower didn't use any Envidor. In the bigger sized trees, we'll go back and check on twig aphid control again, but hopefully it will be sufficient. In one spot where there had been balsam woolly adelgid, it had also been controlled.

At a meeting I had last night in Watauga County (which is sort of EHS central!), a grower shared that in a block of trees where he's had to treat for rosette bud mite, spraying Dimethoate by itself in June, he's had no EHS, even though there is plenty of scale all around him.

So, should we even be treating earlier for EHS? In June perhaps?

ALERT: Also wanted to let everyone know that a new scale which they are having problems with up north in Frasers and other firs -- Cryptomeria scale -- was identified last week in Macon County. It was the first reported incidence in North Carolina.

Scales are definitely becoming more of a problem. Is it the loss of Lindane? Warmer winters? More use of synthetic pyrethroids and Thionex? One thing's for sure, they will make international marketing a lot tougher, as the presence of most of these scales will stop sales.

Twig Aphids

2010-04-05T16:03:00.001-04:00

SUMMARY: Twig aphid hatch is at about 86%.

Jerry Moody and I applied Movento with different adjuvants today. Remember that Movonto is the systemic that needs a good penetrant to get into the foliage. The problem is that several we used last year caused needle burn. Also, we didn't get great twig aphid control because we didn't put it out early enough.

Well, we got it out early enough this year! We tried Movento at the full 10 oz/acre rate either alone or with the following adjuvants: horticultural oil, Eco-Tec, ammonium sulfate, NIS (80/20), Liberate, or Phase.

I checked the twig aphid population at the field site, and there were plenty of aphids -- approximately 1.4 eggs per shoot. I estimated that there was about 86% hatch. There are several 2nd instar aphids. So, you can start scouting for twig aphids now, and certainly by next Monday, you can easily scout for twig aphids.

I think we put in a good study. I'll let you know the results come mid-May.

End of March Assessments

2010-04-01T10:55:00.001-04:00

I've had the opportunity to walk through several Christmas tree fields the last couple of weeks. Here are some of my observations.

BALSAM TWIG APHIDS: I'm still not seeing many fields that have high twig aphid numbers. I finally found a couple that did, but mostly there aren't many aphid eggs. Bryan and I found our first live twig aphid on March 30! It was tiny -- just a fist instar. The weather during April will determine how bad twig aphids end up being. Now we're having warm, dry weather which will allow the aphids to quickly hatch, mature, and start to reproduce -- laying live young. If this kind of weather keeps up, those few aphid eggs will turn into plenty of aphids to curl needles by bud break.

We were in one field that had been treated with Talstar in the fall, that actually had a dead aphid sticking out of the aphid egg. But it's still a bit early to be evaluating how these fall aphid treatments are working. Wait until April 15, and then it should be easy to beat aphids out of trees if they are present.

However, if you didn't treat in the fall, and you need to control twig aphids, don't wait until the 15th unless you are using either Di-Syston or Thionex. All other materials including Asana, Talstar (Wisdom), and Dimethoate can be applied now.

BALSAM WOOLLY ADELGID: I visited another field yesterday where several trees were showing symptoms of woollies (flat tops, swollen buds, stiff trunks), but it was extremely hard to find any live woolly on the trees. What we did find were on the buds, and we had to look at lots of buds before we found them. These trees had been completely untreated in 2009. Therefore, I think we're seeing quite a bit of winter kill of BWA, but don't assume they are all killed out. Fields with symptoms of woollies should still be treated for them.

SPRUCE SPIDER MITES: I have yet to find a field with more than just a few spider mite eggs this spring. I'm sure they are out there, but for now, I don't think there are many growers that will have to worry about this pest.

HEMLOCK RUST MITES: Rust mites are really active this spring -- much more so than in the last couple of years. We walked through several fields last week that had been treated in July or August with Dimethoate + Asana to control elongate hemlock scale. This is a combination that should create rust mite problems the following spring, but of the four fields we visited, only one had rust mites. The other fields had virtually no mites.

We walked through another farm this week that had been treated with Talstar in October. It was a very large farm that rambled up and over a ridge, dropping down to the river. On the ridge top, the rust mites were nearing treatment threshold. In other areas of the farm, there weren't any.

So what's a grower to do??? SCOUT!!!! You can find the blocks that need rust mite controls and target only those for treatment. It doesn't take a lot of time to scout. A field of several acres can be evaluated in just 30 minutes. That's worth knowing where you need and don't need rust mite control.

Envidor will provide longer lasting control than just dimethoate. After all, it's a long time until summer. Spring's barely started.

Rust Mites & Twig Aphids

2010-03-25T14:36:00.001-04:00

Just wanted to let folks know that I was in a field yesterday that had quite a few rust mites. It was up to our treatment threshold of 80% incidence and at least 8 mites per needle on one shoot. The most I saw was 25 mites on a single needle. So, it's not too early to get out there and look for rust mites.

I haven't seen my first twig aphid hatched out yet, but I'm sure they have started to hatch. Really, there aren't many fields that have much twig aphid in them. You might have to pull of 10 to 15 shoots before you find an aphid egg. Don't be fooled, though. That slight number is still enough to cause damage if we get a warm, dry spring. Of course, we haven't so far, so we might do well with twig aphids this year.

March Madness

2010-03-22T13:24:00.001-04:00

Well. Not quite. I thought it might get people's attention. Of course, people do get a bit mad in the spring. "Mad as a March hare," the English used to say. People are just now realizing what all they have to do this spring -- at least I know I am.

Just wanted to share a few observations I and others have been making this spring.

BALSAM TWIG APHIDS: I haven't seen any hatched yet, but the eggs are getting plump like they are ready to hatch. However, I haven't found any fields so far with a high incidence of twig aphid eggs. You might pull off 10 shoots before you find an egg. I guess last spring it stayed so wet that the aphids didn't reproduce well. Remember, though, that even these low numbers can result in damaging levels of twig aphids if the spring is warm and dry, as the aphids reproduce so quickly.

VOLES: Both Bryan Davis and Doug Hundley are seeing greater than normal vole activity. With all the snow cover, it only makes sense.

Bryan sent the following in a March 17 email, "I have seen a tremendous amount of signs of rodent tunneling under the snow. During the winter when the snow melted on some fields signs were visible and as I've been out over the last two weeks I've thought this is the most sign I've ever seen. I recall seeing some signs of rodents last fall where we were spraying deer repellent and as I've returned to these farms there is more signs of rodent activity. The tracks I'm seeing don't seem to bee tunneling in the soil, but on top of the ground. I haven't seen any damage such as girdling or dead trees in these fields yet. I'm going back to one site today that has had a lot of activity and I'll look closer for signs of damage. As far as control, I had a grower asking about this last fall and I checked with Scott Henson about what they carry at CPS and they had rodenticides, but they came in large volumes. Hopefully now the hawks, foxes and cats can work on these pests."

I've only found voles damaging Fraser fir once -- and in that field they completely severed the trunks of small trees. The poor little trees looked like pencils stuck in the ground. Rodent control on that farm involved controlling the thick grass in the field, allowing the hawks to work it. Like Bryan says, the natural predators should take care of things.

RUST MITES: Bryan and I found some rust mites getting started over the last couple of weeks, but numbers were still very low.

OIL TRIAL FACTS AND FIGURES: Bryan sprayed some trees with the new Saf-T-Side oil last Friday. We used a backpack mistblower and a 2% rate. I'll try to get back there next week and see what the eggs look like. He was using about 100 gallons of water per acre to get good coverage. That is probably more than most growers could use, putting it out 3 1/2 gallons at a time. Another grower we talked to figured he was applying about 8 backpacks per acre for around 28 GPA.

That grower burned some trees with oil last year using his high pressure sprayer. All the needles fell off of some trees. The buds for 2009 weren't touched, and so all that's left is 2009 growth. Here is a picture of one of those trees. Hopefully this new oil will be easier for growers to use and won't cause burn.

Oil isn't cheap. If you are using the regular oils which are about $14 a gallon -- a 2% solution and 300 GPA comes out to $84 per acre. When Bryan sprayed last year, he used up almost a case of oil (5 gallons) on 1,000 trees which cost more than $100 per acre. But, Bryan hopes to market these trees as "pesticide-free" this fall which should give him an advantage over conventionally grown trees.

If anyone sees any interesting pest problems, let me know so I can share them with everyone.

Our Natural Stands

2010-03-16T14:17:00.001-04:00

This picture was taken on Roan Mountain in the last few days. It's still another world up there -- a winter world even though everywhere else is starting to green up. I just wanted to let people see what Fraser fir and the native pests that affect them such as twig aphids, Cinara aphids, mites, and rosette bud mites are adapted too -- harsh conditions! So they can take the cold winter we've had this year.

EHS observations for early March

2010-03-11T10:49:00.001-05:00

I was finally able to make it into the field on Monday! Of course, I had to nurse my sore knee through the wet snow and mud on slippery slopes, but I managed OK with the help of Bryan Davis and Jim Hamilton.

Anyway, I wanted to see how the elongate hemlock scales survived the winter. We collected scales from an area that has never been treated with any insecticides except Di-Syston. What I observed was that about 70% of the scales were dead. Most of the nymphs appeared dead -- 85% mortality. The mature female nymphs were surviving much better. Only 37% of those were dead and some females had eggs ready to hatch.

What will that mean for scale this year? It certainly was affected by the winter weather, but there is still plenty left alive to start all over again this year. Also, treating now for scales probably wouldn't do much, as the most resilient form, the adult female, is about all that's left.

Spring Insecticides for Pest Control

2010-03-10T13:07:00.001-05:00

The weather so far this year has put many people behind already. Many growers treated last fall with insecticides and are hoping to get twig aphid control this spring from those fall sprays. In fact, in talking with county agents, we estimated that at least 4,000 acres of Fraser fir Christmas trees were treated in the fall and will hopefully skip a twig aphid treatment.

But what options do growers have that didn't treat in the fall? I'll try and list them all below. If anyone has any other's they'd like to share, email me and I'll add them. As I go through different materials, I'll be using abbreviations for pests with BWA=balsam woolly adelgid, BTA=balsam twig aphid, SSM=spruce spider mite, HRM=hemlock rust mite, and EHS=elongate hemlock scale.

The first consideration is do you even need to treat for twig aphids? If you aren't cutting out of the trees this year or next, you don't need to control BTA. You should walk through your trees to make sure mites aren't a problem, but you can probably skip treatments.

A second consider is what have you used in the past for insect control. It's important to rotate materials from different chemical families. In other words, products like Asana and Talstar are both synthetic pyrethroids and so have similar modes of action. Think about what you used in past years, and try to use other products this year. For a complete listing of all the chemical families, go to the IRAC Mode of Action Classification.

Another consideration is that it doesn't all have to be done in the spring. You can get control of pests in the summer and fall when you have more time and can pick better weather conditions. At the end of this post, I have some possibilities for when to treat if you have all the major pests.

And just a few more words of wisdom: Remember that all pesticides are dangerous to something -- whether the bees in your trees, or the stream insects below your field, or the man putting it out -- so read and follow the label. Labels can change every year, so be sure to read them each spring. Also, be considerate of your neighbors. Remember that getting good coverage is just as important as what material(s) you choose to use. Also remember that if the wind is blowing, or if it rains before the spray has dried, you are wasting your time and money. Be sure to scout after using any of these products to make sure they have worked.

Anyway, here is a list of products, their rates, different mixes and what they will control.

Horticultural oil. Use a highly refined oil -- 92% unsulfonated residues or better -- at the full 2% solution -- that is 2 gallons in 100 gallons of water. When applied in March with a high pressure sprayer, it will control BTA and HRM very well, and will help reduce SSM, BWA, and even EHS. Be sure to get good agitation so the oil and water don't separate. We're going to be looking closer at Saf-T-Side oil which won't separate in water to see how well that works.
Asana. Can be used anytime from February through bud break to control BTA (5 oz/100 gallons) and BWA (10 oz/100 gallons). Add a miticide if mites are present. Will also knockdown EHS. However, there is also a potential to create problems with HRM and SSM when using Asana -- even the following spring. If BWA control can wait until fall, rust mite problems can be avoided when using this product.
Dimethoate. Use at full rate of 24 oz/acre. From last week of March through bud break will control BTA and knock-down EHS, HRM and SSM.
Dimethaote + Savey -- BTA plus SSM control (the Savey controls the mite eggs). Also Apollo can be used in this manner. Still will only knockdown EHS and HRM.
Di-Syston 15 G -- There might be some folks who are still using this. It will control BTA and SSM and possibly a brief knockdown HRM. Be sure to apply when there is no wind and scout after treatment to make sure it worked.
Talstar. Use at full rate of 40 oz/acre. Will give BTA and BWA control from February through bud break. Should also give control of SSM. (Though Talstar doesn't have any activity against mite eggs, it should last long enough to kill the mites that hatch from the eggs). Doesn't control HRM or EHS well.
Talstar + Dimethoate -- BTA, BWA, SSM and knockdown of HRM and EHS.
Thionex. Use at full rate of 2/3rds of a quart (about 21 ounces) for BWA control. Wait until mid April through bud break to get BTA control as well. (It just seems that BTA control is more reliable with Thionex if you wait until all the aphids have hatched out). Add a miticide if mites are present. Has no activity against EHS.
Thionex + Dimethoate -- BTA, BWA control and EHS, SSM and HRM knockdown. Some folks have been using this mix without scouting first, thinking that it will control about every pest. But control of mites and scales will only be fair.
Envidor. Use at 18 oz/acre for HRM and 25 oz/acre for SSM control. Therefore, if you add Envidor to any of these products listed above, you will also control these mites. Will it keep the mites from developing later in the year or next year? Probably not. I would prefer seeing people keep on scouting and apply when needed -- not as a preventative.
Dimethoate + Asana -- Use dimethoate at rate of 16 oz/100 gallons and Asana at the highest rate of 10 oz/100 gallons. Will control BTA, BWA, EHS and knockdown SSM and HRM. Wait as close to bud break as possible to get the most out of EHS control.This mix would give better control of EHS in summer.
Dimethoate + Prev-Am Use Prev-Am at 0.4% solution (50 oz/100 gallons). Will control BTA, EHS and knock-down of SSM and HRM. Prev-Am has burned trees at higher rates, so be careful, but this mix sure smells better than straight dimethoate!
Lorsban -- will control BTA and knockdown SSM and HRM (?). Will also control BWA in March -- but not once woollies start laying eggs. Will control EHS??? We're still looking at this, but it did a great job last October. We've seen some issues with Lorsban burning foliage, so be careful.

So, what would I use if I had everything -- BWA, BTA, SSM, HRM, and EHS? I would probably either use Asana + Dimethoate and continue scouting for the mites to see it they rebound, treating with Envidor if they do, or go ahead and use Asana + Dimethoate + Envidor (which would be rather pricey). Or, I might wait to control my BWA and EHS in the summer with Dimethoate + Asana, and just use dimethoate in the spring -- and scout for mites later on. If you wait until August or September, you should pick up BTA control for the following year. Or I might use oil in March every year to control all these pests.

Beating Trees to Beat Bugs

2010-02-25T12:05:00.001-05:00

SUMMARY: To decide what insecticides to apply in the spring, it is important to scout in April to determine if twig aphids and mites are present in a field. Use foliage beats for twig aphids and examine shoots for rust mites and spider mites. Always use a hand lens. Though scouting takes time, it will end up saving both time and money by helping to determine exactly what pesticides, if any, are required.

I finally made it to Ashe County yesterday. It was good to at least make it into Christmas tree country again. I saw several blue birds which is always fun.

Bryan Davis and I chatted with some growers who had treated different blocks of trees with Dimethoate + Asana at different times -- anywhere from the end of June through mid September. They wanted to know if they had controlled the elongate hemlock scale and if they could skip twig aphid treatments in the spring. It will provide us a great opportunity to evaluate different timing of these materials for both scale and twig aphid control. After all, most of the fall treatments that have been followed over the last several years have been with Talstar, not Asana. It will be interesting to see under different conditions how well the Asana performed. But our conversation also made me realize what all growers will be facing this spring.

Of course it's so snowy, you can't even get out in the field now, even if you could tell anything about pest control. If you can make it to the field, there is a layer of ice on the snow that makes walking difficult. People are sitting around knowing they are already getting behind this growing season before it even gets started. In the spring, growers need to plant, fertilize, get herbicides out and insecticides. Some even have a bit of shearing that needs finishing. I'm afraid, scouting may be one of those things that doesn't end up getting done.

How do you get it all done when you don't have the time? Fortunately, scouting doesn't have to take a lot of time. The two most important pests a grower needs to evaluate in the spring are twig aphids and rust mites. Neither should take a lot of time to assess. As pictured with this post, taking beats of foliage on just a few random trees in each block will let you know if fall treatments with insecticides have controlled twig aphids. Start this in mid-April.

This photo shows a beat with a lady beetle larvae (the big bug) and four twig aphids (one fairly big and three small). Always use a hand lens when you look at what fell out. If you find more than a couple of trees with twig aphids, you will need to treat again in the spring. At the same time when you look for twig aphids, pull a few shoots and look with a handlens for rust mites. If there are only a few, make a mental note to check again in a few weeks to see if the numbers are increasing. Remember that rust mites are very small. If you are just looking at foliage beats, you'll miss finding all but the heaviest populations of rust mites. By taking both foliage beats and pulling shoots, you will also learn if spider mites are a problem.

The fields I mentioned earlier that had had Asana in the summer or fall are much more likely to have rust mites this spring -- but there's no reason to assume mites will cause enough damage to worry about. The earlier the Asana was applied, the more of a problem rust mites are likely to be, so we advised the growers to scout those fields first. But if this spring stays fairly cold and wet, rust mites might never become a problem. As I start getting out in the field in March, I'll let everyone know in this blog what this spring looks like as far as rust mite pressure in general.

Unfortunately, some growers seem to be skipping scouting, and just treating everything in the spring with Dimethoate + Thionex, thinking that these two materials will control everything. After all, Dimethoate will control spider mites, rust mites, twig aphids and some scale, and Thionex will control twig aphids and woollies, and neither is that expensive. But remember, Dimethoate's control of mites can be short lived, and Thionex gives no added help with scale control. Twig aphid control with Thionex has been variable, and we're not sure why. These are also the two most toxic insecticides that growers use, and they also smell really foul, making them an issue with neighbors. And why spray anything at all if you don't need to? If you treated last summer and fall, you might not need to treat again this spring. And even if you didn't, twig aphids and mites aren't always a problem every spring.

Scouting takes time, but it also saves time, money and pesticides. If you aren't confident about scouting, call Extension for help. There are also scouts working in the counties that can be hired to do your scouting for you. For their names, call the County Extension Agents in some of the bigger tree counties.

I hope to get out to the fields we talked about yesterday and some I treated last fall starting the second week in March. I'll let you know what I find. In my next post, I'll go over some of the pesticides and timing that can be used for pest control this spring. But remember in April, to take your beat sheets (white plastic plates work great --thanks for that tip Doug Hundley!) and hand lens with you.

If You're Missing Di-Syston...

2010-02-22T13:40:00.003-05:00

SUMMARY: If you are treating for twig aphids this spring, there are many choices available both in pesticides and spray equipment. It is not necessary to treat trees for twig aphids until two years from harvest. Larger growers are using tractor-driven airblast mistblowers. For smaller growers, a backpack mistblower is a great alternative.

Many folks have started spraying in the fall for Cinara aphids and balsam woolly adelgid, which frequently results in twig aphid control the following spring. If you aren't one of those people, you will probably need to treat for twig aphids this spring.

Twig aphid control is only important the year of sale and year before sale. There is no need to control twig aphids in younger trees, as the new growth will hide the needle curl. If there is damage and even reduced growth, the trees tend to set extra buds for the following year, and growth will not be slowed down at all. But if it takes 2-3 years to harvest all the trees out of a block, a grower may end up treating 4-5 years in a row for twig aphids.

Traditionally, people treated right before bud break. Since most were using the granular formulation of Di-Syston, this was the a good approach as it was important to wait until all the eggs had hatched. This product is no longer available for use and other products can be applied much earlier in the spring.

The loss of Di-Syston will especially impact the smaller growers who may not have spray equipment. Most larger growers have switched more and more to using tractor-driven airblast mistblowers as the price of Di-Syston increased during recent years. This equipment gets good twig aphid control provided there are enough access roads. Adding a material to the pesticide to increase droplet size is helpful to both reduce drift and get better coverage. Be sure to scout in the middle of the block after April 15 where coverage may have been light to make sure control is adequate. But if you don't have a mistblower, you will need to decide how you will treat in the spring.

A high pressure sprayer is always the best choice for pesticide application as you will get the best coverage. For twig aphid and mite control, it is not necessary to crank up the pressure or use a straight-stream spray pattern as you would with balsam woolly adelgid control. Instead, reduce the pressure, broaden the pattern, and you will find you will get better foliage penetration. Don't try to treat more than 2-4 rows at a time, even in smaller trees. Unfortunately this application method is slow, and smaller growers often can't afford these sprayers. If they hire someone else to spray their trees, and the weather doesn't cooperate, they risk not getting their trees sprayed at all.

If you are a smaller grower, a backpack mistblower may be the answer. This equipment gives enough coverage to control all Fraser fir pests including woolly adelgid. It gives much better coverage than a regular backpack sprayer. There are several lower acreage growers that only use this to apply insecticides. The sprayer is not for the physically weak! It is heavy, but even I can handle it on steep ground. It sprays faster than I can walk, but you can change the settings to reduce spray output. And priced between $600-700, most growers can afford it. You will find you will apply around 50+ gallons of water per acre which means a lot of trips to fill up, so having a nurse tank is helpful.

Whatever equipment you use -- mistblower, backpack mistblower, high pressure sprayer -- be sure to treat trees from opposing directions. Try spraying some trees with plain water to make sure you are getting good coverage. And DON'T TRY TO SPRAY WHEN THE WIND IS MORE THAN 10 MPH or IF IT'S ABOUT TO RAIN. It's just a waste of pesticides, time and effort, and makes the entire industry look bad.

There are many choices in pesticides for spring pest control. I'll go over these in another post. But remember, for many of them you can spray beginning in March -- which is just next week! (Guess we'll have to get rid of the snow first!) Don't wait until the last minute as you never know if the weather will allow you to spray or not.

So You Treated in the Fall...

2010-02-16T11:02:00.005-05:00

SUMMARY: If trees were treated in the fall with Talstar or Asana, it may not be necessary to treat in the spring for twig aphids. However, it is important to scout to determine if twig aphids have been controlled, and if there are other pests that need controlling.

Spring will come. I know it doesn't seem like it now, but it will! And one thing that Christmas tree growers need to think about is what to do for insect and mite control in the spring.

What each grower has to do depends on two things: 1. what they treated with for insect control last year and 2. what pests you have in your trees.

What you did last year sets you up for this year. Many growers are treating their market trees in the fall to control Cinara aphids, woollies, and other pests. This is a good way to set up a more problem-free spring. If you did treat last fall, this post is for you! Unfortunately, that doesn't mean you get to be lazy this spring! You still need to scout.

Hopefully if you treated in the fall with either Talstar or Asana, you should have controlled your woollies and Cinaras, your twig aphids for this spring, and not created any problems with rust mites The key word though -- I use these kinds of qualifiers a lot! -- is "SHOULD." Control of none of these pests is guaranteed. Bugs don't read books after all. That's why you need scout come spring.

It doesn't have to be an extensive scout, just a quick look-see. Check on any old woolly trees and see if you can find any live woollies. Beat a few trees to see if any twig aphids are falling out (be use to use your hand lens to make sure you can find the littlest ones). Also pull some shoots and look for rust mites.

You should wait to do this first checking until the twig aphids are close to being fully hatched. Sometime the 1st or 2nd week in April, make your evaluations.

If you don't find anything -- GREAT! Come back again right before bud break and checkagain, just to make sure that twig aphids have been controlled. Remember that these aphids multiply rapidly, so their numbers can quickly build up.

If you found many aphids, you will probably need to treat for twig aphids again -- that is, if they are go-to-market trees that you are concerned about needle curl. Why didn't the fall chemicals work? It might have been an issue with coverage, or not a full enough rate. In any case, it's time to haul out the spray equipment and get busy before bud break.

If you are't finding twig aphids, but you are other pests -- say a few rust mites or spider mites -- the question of treating because a bit harder. These pests have the potential to build in numbers and cause damage -- but the numbers can also crash, resulting in little to no damage. My suggestion would be to keep scouting to see if numbers are increasing or not. If they have reached treatment threshold, a good miticide such as Envidor should give season-long control. If you are seeing these early enough in April, you can also get good control using a 2% horticultural oil solution. Remember that coverage doesn't have to be as good to control rust mites, but it is more of an issue with spider mites.

If you are finding elongate hemlock scale, you can treat in the spring, or you can wait until summer. If all you have to control is scale, I would probably wait until summer. If you are spraying for other pests though, go ahead and add the materials to control scale as well. Control for scale is somewhat reduced in the spring, but some have gotten decent control. I would wait as close to bud break as possible to allow the scales to produce as many crawlers as possible.

Just one scouting trip wouldn't be enough to give me peace of mind. It's important to check again right before bud break. Now if only 1-3 aphids are found, you can feel a bit more safe that twig aphids won't cause much damage. However, if more than a couple of trees have aphids, and you can beat out several, you might need to treat quickly to avoid damage. Once bud break has started, Dimethoate is a good choice to get control.

Scouting takes time, but it's worth it to identify fields where you can avoid making another insecticide application.

Organic Christmas Tree Project

2010-02-01T14:18:00.008-05:00

Photo caption: The Extension organic site in June, 2009, a little more than a year after planting.

SUMMARY: In 2008, an extension organic Christmas tree project was started in Alleghany County. Growth has not been as good as normally produced trees at the same site, and costs are higher. It cost $1.50 per tree in materials and labor to put ground cloth around these trees at planting to reduce weed competition. It takes about 8 times as long each year for weed control (weed eater vs. applying low rates of Roundup). The tree terminals in the organic site are about 1/2 as long.

There has been interest in growing Fraser fir for Christmas trees organically for many years in western North Carolina. To my knowledge, there are 2 or 3 certified organic Christmas tree growers in NC that harvest a few hundred to a few thousand every year.

Back in the mid-1990's, several of us in extension did surveys of customers to determine if there was a market for organic Christmas trees. I went to a couple of choose and cut farms (Doug Hundley helped me at the one in Avery County), and Jeff Owen, the area extension specialist with Christmas trees went to an organic grocery store in the Asheville area.

What we found at that time didn't indicate a great demand for organic Christmas trees. Many of the people that Jeff interviewed that were buying organic food either didn't celebrate Christmas or they didn't use Christmas trees. People that I interviewed were interested in integrated pest management as a way of reducing pesticide use, but they were primarily wanted to have a pretty tree at a reasonable price. They didn't indicate that they would pay more for an organic Christmas tree.

However, in the past 15 years, this may have changed as more people are buying organic products. "Green" is definitely in and many people are convinced that organic production is the most environmentally friendly way of producing any crop. I myself prefer organic bananas, carrots and tomatoes because they haven't been loaded down with nitrogen, and therefore, in my opinion, they taste better.

Fraser fir, being a somewhat slow growing and finicky plant, doesn't lend itself to easy organic production. Pest control is really no problem. Even though there are several introduced pests that aren't easy to control (namely the balsam woolly adelgid and elongate hemlock scale) practically all pests can be kept at bay with horticultural oil. And now that there is Saf-T-Side oil without the issues of oil separating out and burning foliage, pest control shouldn't be a problem.

The big problem is weed control. Historically, this has always been the biggest issue with Christmas tree production. Weeds, and especially grasses, will always outgrow conifers. After all, that's why Fraser fir is found at the highest elevations -- because they can grow there and other plants don't. In fact, the top of Mount Mitchell was never logged -- not because Govenor Craig made it a state park and therefore saved it, but because the very top of the mountain was almost entirely Fraser fir. The economically important red spruce was found at slightly lower elevations.

Using low rates of Roundup not only stunts weeds to allow trees to grow, it shifts the ground covers away from grasses to clovers and other low-growing perennials. These living ground covers then become weed control, so that harder to control weeds like poke and ragweed can't get a foothold. That is impossible to reproduce organically without disturbing the soil.

In 2008, several of us started an extension organic project at the farm of one of our county agents, Della Deal. She had a small farm that had just been set in Fraser fir, that she was willing to donate for the project. Also involved were myself, Jeff Owen, Bryan Davis, and Richard Boylan, the alternative agriculture agent in Ashe and Watauga Counties. My goal was to see how much it would cost us to grow a pretty organic Fraser fir Christmas tree. I wasn't interested in an experiment looking at different options for fertility and ground cover management. I wanted to use our best guess as to what would work.

To control weeds, we used an 18 inch square piece of ground cloth that was placed around each tree and secured to the soil with staples, keeping the weeds from growing right up against the tree. Della's field was about 1 acre in size, and we initially had every intention of doing the whole acre organically. But 89 man-hours later, when we were only 1/2 through, we realized that we wouldn't be able to complete the whole project. Necessity being the mother of invention, we decided that the lower half of the field we would call "late organic."

To get organic certification, you can't use unlabeled products for three years. Fraser fir is more than a three year crop. So we decided to handle the trees like a commercial Christmas tree grower would for the first three years, and then switch to organic production for the last three years. We figured between the time in cutting the fabric (it's cheaper to buy it in rolls), putting it around the seedlings, the cost of the fabric and staples, and our labor (we "paid" ourselves $10 per hour), it cost $1.50 per seedling to use the fabric.

Of course we had set up the whole field all wrong. If we had known we were going to be doing this, we would have blocked the field off with a plot of "organic" next to a plot of "late organic" replicated through the entire acre. That isn't what happened. The organic section is at the top of the hill where it is rockier, and has no doubt lead to more issues with seedling mortality.

Our second stumbling block was the weather in 2008. It was DRY. In fact, I'm surprised we lost as few seedlings as we did. There were 6.4% mortality in the organic trees and 3.3% in the "late organic" trees from May to October, 2008. These numbers are not outrageous for newly set trees. Really considering how little water fell that season, the survival was remarkable. I was really worried that the ground cloth would make the soil too hot and cook the little seedlings, but that didn't happen. And if you look at the pattern of mortality in the field, you can see that most of the seedlings died in the organic section where it was rockiest. In the upper-most area where it isn't rocky, we lost almost no seedlings.

Of course, the lack of rain helped with weed control. I was surprised how little it took to control the weeds in the organic section. Bryan used a weed-eater twice in 2008. We have some problem weeds in this field including lots of fescue, spotted knapweed, and poison ivy. Because of the PI, Bryan won't let me help him weed-eat as I am quite allergic to it. (He is probably more worried about me cutting down little trees). .

Spring of 2009, we fertilized the trees with organic fertilizer which we scattered on top of the ground cloth. We were kind of late knocking down all the weeds that spring. Bryan went through with a weed-eater in May, but the trees had already started to grow and they were shaded too much, causing the growth to be stunted and off color. By the way, it typically takes Bryan 4 hours to weed-eat the entire organic plot which is about 1/2 acre. He applies the Roundup (8 ounces per acre) on the "late organic" which is also about 1/2 acre in about 1/2 hour.

On July 21st after the trees had hardened off, Byran and I went through and measured the terminal growth of a random selection of seedlings in both parts of the field. There was tremendous variation, as you always see with Fraser fir. But the seedlings in the "organic" section grew an average of 4.1 inches and the "late organic" an average of 7.4 inches. That's a big difference.

What I've learned so far is the following. First of all, we really didn't set up the field correctly for organic. It probably isn't even the best field to grow organic trees. It faces southwest, which will mean it will be hotter and there will be more problems with spider mites. There was a lot of fescue in the field prior to planting. We didn't put down any organic matter prior to planting. If I had my druthers, I would have incorporated as much organic matter as possible, and tried to kill out the grasses before the trees were ever set. It would have been best to start a year before setting the trees to get the site ready. But when we started, the seedlings were newly planted. You don't look a gift horse in the mouth, so we went with what we had available.

Secondly, we need to be quicker knocking down the weeds in the spring so the young seedlings can grow better. Thirdly, we need to find a better source of fertilizer and think of other ways of putting it out.

I am speaking at the Organic School in Asheville on March 6 & 7. I don't know if anyone will come or not, but I certainly enjoyed pulling together the talk and all the information. I keep posting on this site how things are looking with this project.

Elongate Hemlock Scale Trials 2009

2010-01-27T12:40:00.010-05:00

Photo captions from left to right: Female scale flipped over to show small area, outlined in yellow, through which the scale feeds. Male elonagate hemlock scales produce a white, fluffy covering which can bee seen on the needles and may affect sales. Field shot where scale spread has been monitored over a 12-month period

SUMMARY: In 2009, a series of pesticide trials were conducted to determine timing and materials for scale control. Results indicate that the best scale control is achieved in the summer. Scales can be controlled in the spring, but there will be 5-15% less kill. Treatments made after mid-September also do not result in good control. The best materials for control continue to be Dimethoate plus either Asana or Prev-Am. However, in a fall applied trial, Lorsban gave excellent results. Safari has given variable results, as has the new insecticide, Movento. Horticultural oil continues to give control at about 65-75% kill. At one field site, scale spread to as many as 1/3 more trees from the summer of 2008 to 2009. However, tree growth appeared to be hardly affected. Current control recommendations are found at: http://www.ces.ncsu.edu/fletcher/programs/xmas/ctnotes/ctn037.html

Elongate hemlock scale (EHS) has continued to spread in Christmas tree farms in western North Carolina. I had hoped that a cold winter last year would reduce scale numbers, but that was not the case. I have been conducting EHS control trials since 2003. This past year, I had 4 field trials looking at different materials for scale control as well as assessing scale spread in a 5th field.

Past work has indicated that a mixture of Dimethoate (@ 16 ounces per 100 gallons -- a pretty hot mix) + Asana (@ 10 oz/100 gallons) or the Dimethoate + Prev-Am (@0.4% solution) gives good control in the summer. Last years trials really confirmed that the Dimethoate by itself does not work as well, nor gives as long lasting controls. Past work also indicated that the best control would be achieved in the summer (July through early September). Treatments made in 2008 in the spring did result in good control (92% of scales killed in one test), but slightly better results were achieved in the summer.

Most Christmas tree growers are well acquainted with Dimethoate and Asana. Some may not know as much about Prev-Am.

Prev-Am is an insecticide, miticide and fungicide. It is produced by Oro Agri and is made by a mixture of "Borax, cold-pressed orange oil, and various biodegradable surfactants." According to company reps, Prev-Am will disrupt the exoskelton of the insect. It also will increase translaminar movement of products across the surface of the needles, and reduce surface tension, thereby improving penetration. More information about this product is available at the Oro Agri site at: www.oroagri.com. The Prev-Am is not considered an organic product because of the amount of borax. However, it certainly smells good. It can help mask the smell of Dimethoate. It probably aids Dimethoate by increasing the penetration of chemical into the scale. However, we have seen needle burn a few times when it is used at the full labeled rate of 0.8%. I have not seen burn at lower rates, and so have recommended the 0.4% solution to mix with Dimethoate.

The first picture aboves shows why it is so hard to kill these scales. They are armored scales, but they are covered both on top and underneath. There is only a small area (outlined in yellow) through which the feeding tube fits, and the scale is not protected. The Prev-Am may help in getting materials through to the scale to kill it.

Anyway, that's where things stood at the start of 2009. There were still a lot of questions about scale control. When does the treatment window "close" in the fall? How much will EHS spread in a year? Can the rate of Dimethoate be reduced when using Prev-Am? What other materials can be used for control? And could a grower get as good control with a back pack sprayer as a high pressure sprayer? Jerry Moody wanted this question answered especially as he had several folks with localized scale, and they just wanted spot control.

What were some of these other materials? In 2009 we looked at Movento, Safari, Mavrik, Talstar, Lorsban, and Vintre as an adjuvant to Dimethoate.

Movento (spirotetramat) is an insecticide labeled last year by Bayer. This product is supposed to be an excellent systemic, but it requires the use of a surfactant. Also, they were recommending it be applied twice, with applications made 2 weeks apart. (Some of you may know that Movento labeling issues have arisen. A judge stopped the sale of Movento, because there was not proper public comment posting by EPA. This has been stayed until mid-February, and the company hopes that all labeling issues will be resolved. In the media, there were reports the stop-sale occurred because Movento kills bees. Well, practically everything kills bees. Even spinosad, an organic product, is highly toxic to bees. However, most materials applied in the evening after bees have stopped their activity do not end up harming them).

Safari (dinotefuran) is a neonicotinoid similar to Merit (imidacloprid), the product most often used for hemlock woolly adelgid control. Jerry Moody and I tried it against balsam woolly adelgid, and it worked very well. Research from other states indicated that it was controlling EHS in hemlocks.

Mavrik is another synthetic pyrethroid that Jerry Moody was interested in. Talstar is also a synthetic pyrethroid similar to Asana. I didn't think it would work as well as Asana, but I didn't know for sure.

Lorsban is an organophosphate which I didn't think had that much activity against scales, but which Bryan Davis said folks in Michigan were recommending for scale control. Also, the folks at Oro Agri wanted us to look at another product of theirs called Vintre which doesn't contain Borax and is labeled for organic production instead of the Prev-Am.

I ended up with 4 pesticide trials for EHS control. One was applied in the spring, one in the summer, and 2 in the fall. The spring applied trial (April 28) was mostly to look at Movento. In the summer (July 7 and boy howdy was it hot!), Bryan Davis and I put out 7 different products. At the end of August (the 26th), Jerry Moody and I put out different products with either the back pack sprayer or a high pressure sprayer. Then in early October (the 8th), Bryan Davis and I tried a few products to determine if the treatment window really was closed.

I'm not going to list all the treatments, rates, treatment dates and results as it gets confusing. But I will summarize the results. The best controls (96%+ kill) were with Dimethoate plus either Asana or Vintre in the summer. Dimethoate worked well at both rates -- either 8 or 16 oz/100 gallons when mixed with the Vintre. In the past, lower rates of Dimethoate haven't worked so well with Asana. The Vintre, used at 0.5% solution did cause burn, so I'm going back to the Prev-Am.

Safari and Movento gave variable results. Movento applied in the spring with 2 appliecations made about 14 days apart, gave good control. But when applied just one time in the summer, it didn't. I think we still need to play around with the adjuvants used with Movento until we find the right one. Maybe Prev-Am would work.

Safari when applied in the summer with the Vintre gave good control, but when applied in either August or October -- and without the surfactant -- didn't. Safari's control may take longer than I give it, however. Last year, Jerry Moody had a grower that treated his farm with Safari, and when I went out about 6 weeks later, his EHS control was poor. However, when we went the following spring to pick out a site to spray in, the scales were all gone. So I plan on rechecking these results this coming spring. Also I plan on looking more at both of these materials in 2010.

What didn't work at all? Mavrik didn't, and Talstar + Dimethoate wasn't as good as Asana + Dimethoate. A new encapsulated oil called Saf-T-Side didn't control the scale any better than oil normally does, but it also didn't cause needle burn when applied on a very hot day. Because of these results, I plan on looking closely at Saf-T-Side for twig aphid control ithis spring.

There were a couple of surprises. The real surprise for me was the Lorsban. When applied in early October, it cooked them. I definitely want to work some more with this product in 2010. Another surprise was at the field trial applied in August, control was actually better using the back sprayer than the high pressure sprayer. But then, I was really soaking those handful of trees down. That just proves again the coverage is everything.

The real questions remains, how big of a problem is EHS really? It is definitely spreading, both in Fraser fir and in hemlocks throughout the mountains of North Carolina, and I think in Tennessee and Pennsylvania as well. At one farm (pictured above), Bryan Davis and I flagged trees the summer of 2008 that had scale on them. Then I went back this summer with Meghan Baker, the County Extension Agent in Watauga, and looked at which new trees had scale. In 2008, 26% of the trees had scale and in 2009, 54% did. But several of the trees flagged in 2008 didn't appear to have scale in 2009, and so the real increase was 33%! But even though scale was spreading, the trees actually looked better the summer of 2009 than they did the summer of 2008 -- just because they finally had some rain on them. The trees hadn't been sheared yet, and so I measured the terminals of all the trees. The average terminal growth for trees with scale in 2008 and 2009 was 16.9 inches. For trees with scale only in 2009, terminal length average more -- 19.1 inches. Trees with no scale at all (maybe they are growing so poorly they make bad hosts) had an average length of 15.6 inches. So perhaps scales are reducing growth somewhat, but not that much.

That begs the question -- why control scale then? I think the biggest reason is the unsightly white fuzz that gets on trees in the summer (pictured above) when the males are mostly produced. Christmas trees have to be pretty, and this fuzz is not. Also, trees with scales can't be shipped out of the country.

So what are my current control recommendations? I have them all written out in a new Christmas tree note on the Elongate Hemlock Scale found at: http://www.ces.ncsu.edu/fletcher/programs/xmas/ctnotes/ctn037.htm

Of course there are still unanswered question. I guess I be looking at a lot more scales in 2010!

Interesting Results with Safari for Woolly Adelgid

2010-01-25T14:32:00.009-05:00

Picture caption: Field site where Safari was applied in July, 2009 was heavily infested.

SUMMARY: Safari controls balsam woolly adelgid well, and may work well even with incomplete coverage. However, more research is needed.

Safari (dinotefuran) is one of the neonicotinoid insecticides. Their mode of action is similar to the natural insecticide, nicotine. The most commonly used neonicotinoid is Merit (imidacloprid) which many people have used for hemlock woolly adelgid (HWA). Safari, however, is far more water insoluble than Merit, and control of HWA has proven to take weeks instead of months as it does with Merit.

In fact, researchers are now applying Safari in a spray form just to the trunk of the hemlock and getting good control. Now that's quite a systemic if the chemical is moving through the bark and up to the needles.

Jerry Moody, the CEA in Avery County and I tried Safari against balsam woolly adelgid (BWA) 2 years ago, with very good results. Oddly, this material will not control twig aphids. How something is so good against adelgids and won't control aphids, I don't understand. It is also labeled for scale control, though control of elongate hemlock scale has been variable. (I will talk about that more in a future post).

In any case, Jeff VAnce, the CEA in Mitchell County and I decided to try Safari against BWA in a field trial this summer. We mixed Safari at 8 oz/100 gallons and then applied it one of three ways -- with a thorough spray, only hitting the trunks (and using about 1/2 the water and moving twice as fast), or not spraying the tree at all but just hitting the ground. The treatments were made July 1 with a high pressure sprayer.

I never thought it would work. After all, systemics don't work as well against BWA as they do against HWA because BWA is feeding in the bark and not the needles. However, it did work well.

Before anyone gets too excited, remember that we had an awful lot of rain last summer. This may have allowed the chemical to get into the tree better than it would in a normal year. The results are exciting, and we will try it again this year.