Getting the Most Bang From Your Pesticide Buck

At the North Carolina Christmas Tree Association meeting in Boone on Thursday, March 1, Doug Hundley, Brad Edwards, Brian Davis and I talked about getting the most out of the pesticides you use to control pests in Fraser fir. The following is an outline of what we talked about.

First some updates:

1. The uses of endosulfan (Thionex) are cancelled as of July 31, 2012, so if you have any of this product, use it this spring or dispose of it properly. I blogged about this on June 11, 2010. 
2. Sniper (active ingredient bifenthrin) has a new Christmas tree label. Click here for the Sniper label.
3. Safari (active ingredient dinotefuran) has additional labeling for Christmas trees. Click here for the supplemental Safari label. You need to have this in your possession if you use this product on Christmas trees.  I blogged about this on January 5, 2012. 
4. A combination of Safari and Sniper controls multiple pests. With the Safari, you get elongate hemlock scale (EHS) and balsam woolly adelgid (BWA). From the Sniper you get BWA, spruce spider mite (SSM), balsam twig aphids (BTA), and Cinara aphids. Using this in August to early September provides the best control of most Fraser fir pests without creating more problems with rust mites (HRM) and having the least impact on predators. About the only pest that these will control control are HRM and rosette bud mites (RBM).

Next, what will always be important: 

1. Cultural practices. Using proper cultural practices prevents a lot of pest problems. That's the biggest wheel of the pest control machine. There are many cultural practices that help us with pest control. We mentioned a couple of them at this meeting.
1. Chainsaws. Brad talked about this one. The hardest to control pests like BWA, EHS, and RBM can be partially controlled by cutting out heavily infested trees. Some growers have even harvested a field just using this method of pest control without ever using a pesticide. And even if you do spray, it will help the control last longer because you've gotten rid of a big source of reinfestation. After all, nothing kills 100% of the bugs.
2. Nitrogen. Brian talked about the fields of young trees where they are first seeing EHS were fertilized with 18-46-0. That's because when you're feeding your trees, you are also feeding the pests! With good clover groundcovers, consider skipping nitrogen applications until the trees near harvest.
2. Scouting. Scouting is the steering wheel for the pest control machine. Identify the major pests -- RBM, EHS, and BWA. Then as trees near harvest, keep an eye on aphids and mites. Brian told the story of watching SSM populations crash in trees last summer because it was wet and humid and he was seeing the predatory mites. He ended up not treating thousands of trees because he knew through scouting that natural controls were working.
3. Coverage. The smallest wheel of the pest control machine are pesticides. But if you're going to use them, be sure you don't waste them. Safari is a good systemic. But even with this product, we're finding that the best controls of pests like EHS happen when the grower gets really good coverage.
4. Natural predators. Protect them so they can protect you. We are finding a lot of the EHS parasitic wasp, Encarsia citrina. Lady bugs, lacewings, hover fly larvae, predatory mites -- they are all important. So how do you protect them? 



A great home for predators!

1. Don't use a pesticide unless you have to. Scout first, only treat for what you have. And don't try to overprotect young trees. A few aphids and mites in them won't hurt one bit.
2. Keep your groundcovers going. That provides food for predators and greater biodiversity.
3. Switch to treating in the fall when predators aren't as active.

What are your pest control priorities?

If you have to treat for RBM, you have to treat in a very narrow window. The second priority would be EHS control. If you don't have these but have BWA, then treating in the fall is a great option. And don't worry about aphids and mites until you are nearing harvest. How do you know what your priority is? You scout of course! 

In the next few weeks, I plan on launching a new website that goes over all the treatment options -- pesticides, times of year -- to control all Fraser fir pests. I'll blog about it when it goes public.