The Value of Christmas Trees

"...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 stop toward the will to plant and care for them (Arthur Sowder, US Forest Service, 1949)."

Monday, December 13, 2010

How Things Have Changed

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 (, 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

Thursday, December 9, 2010

Needle Drop in Scale Infested Trees

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.

Thursday, November 18, 2010

Updated Results on Scale Control

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.

Wednesday, November 10, 2010

Scales & Needle Drop

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.

Thursday, October 28, 2010

More Algae Control Results

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.

  1. Untreated check
  2. SA-20 disinfectant @ 1 teaspoon per gallon on May 5
  3. Daconil @ 3 pints per acre on May 5
  4. Dithane @ 1.5 pounds per acre on May 5
  5. Kocide @ 3.5 pints per acre on May 5
  6. Kocide applied twice on May 5 and May 19
  7. Kocide on May 19
  8. 3% bleach solution on September 25
  9. 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.

Wednesday, October 27, 2010

More Info on Fall Needle Shed

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.

Monday, October 25, 2010

Fall Needle Shed

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

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.

Tuesday, October 19, 2010

Movento Gets Relabeled

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.

Monday, October 4, 2010

Updates on Website

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:

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.

Friday, October 1, 2010

Time for Annual Bashing of Christmas Trees

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.

Monday, September 27, 2010

A Word About Spray Suits

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!)

Wednesday, September 1, 2010

Cryptomeria Scale Found in Ashe County

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.

Friday, August 27, 2010

Algae Control Results

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:

  1. Kocide 3000 at 3.5 pound per acre. This is a copper based material which is made up of 30% copper. Kocide label.
  2. 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.
  3. 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:
  1. Cosan, an organic disinfectant, at 2 teaspoons per gallon
  2. 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.
  3. Kocide applied twice -- on May 5 and again on May 19
  4. 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.

Thursday, August 26, 2010

Some HWA Pics

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.

Tuesday, August 24, 2010

2010 Growth in Organic Demonstration.

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.

Wednesday, August 11, 2010

NCTA Meeting

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:

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.

Wednesday, July 28, 2010

Some Scale Control Results

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.

Friday, July 23, 2010

Japanese Beetles

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.

Tuesday, July 13, 2010

Some Interesting Pictures

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.

Thursday, July 1, 2010

Doug's Color Wheel

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.

Wednesday, June 30, 2010

A Good Day for Scales to Die!

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. 

Monday, June 28, 2010

Some Success with Safari

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

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!