Ready Or Not!

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

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

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

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

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:

1. Sanmite which like Envidor controls all stages of both spruce spider mite and hemlock rust mite
2. Savey which controls the eggs and immatures of spider mites -- no activity against rust mites
3. Apollo which has the same type control as Savey
4. 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

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!