At Planting Insecticide Decisions

— Written By

 Early Season Insect Control in Peanut in 2012: Making Sense of Your At-Plant Insecticide Options R. L. Brandenburg, D. Ames Herbert, Jr., and D. L. Jordan

NC State University and Virginia Tech

The beginning of the growing season in 2011 had a number of the proverbial “monkey wrenches” thrown into the spokes when it came to thrips control. First came the news that Bayer CropScience was dropping the peanut and cotton portion of the Temik (aldicarb) label on a phased out schedule. Then the schedule suddenly became accelerated when production was abruptly halted. What at first, was an opportunity to begin phasing out of the use of Temik at-plant and looking for other options, suddenly became a desperate scramble to find available product replacements reminiscent of folks in the battery section of Wal-Mart on Christmas Eve. Some people got what they needed, but most did not and had to quickly look for additional options. Other products also were hard to obtain in some areas.

Fortunately there are some good options like phorate (historically sold as Thimet for many years) and acephate (historically sold as Othene). Both of these name brands have been off patent for quite some time now and there are a number of available generic products with the same active ingredients. Phorate has typically performed well for us and gained a bit more popularity when tomato spotted wilt virus became an issue since phorate has an added benefit of giving the peanut plant a little more protection against the virus. When it comes to thrips control, phorate ranks a little bit behind Temik, but it is still a good product. In lighter, sandy soil, we often get a little bit of phytotoxicity, but rarely do we see any yield loss.

We have investigated various formulations of Orthene (acephate) for many years ranging from the in-furrow liquid sprays to hopper box treatments, to the in-furrow granular formulations. Over the years we have seen a few problems with stand loss, but never with the in-furrow sprays. A number of farmers have used it successfully for many years and the three of us have tested it a lot including tank mixed with several other products. We observed rapid uptake of the product under less than optimal growing conditions and on some occasions it would out perform Temik when conditions were unusually cool.

So as the 2011 growing season began to unfold, the typical phorate injury was noted, but reasonably good thrips control resulted. In the case of acephate use in furrow, there appeared to be a number of problems with delayed emergence and stand loss. In some case, it was fairly severe, but in most cases the crop did recover. This was our first experience with delayed seedling emergence being associated with the use of a liquid in-furrow spray of acephate, but our past testing always used Valent’s product. Valent is no longer the manufacturer and distributor of this product.

Just before Christmas we received news that a “generic” formulation of aldicarb called Meymik 15G received approval from the EPA for use in 2012. The availability of this product potentially changes things considerably for the 2012 growing season. However, we think it is important to review a few important points before you make your final choice.

First, we do not know if the slow emergence and stand loss associated with Orthene in 2011 was due to specific weather conditions we experienced in 2011, the seed quality (seed quality can be less-than-normal following a dry season like 2010), or if it actually had something to do with the product itself. We have received no input from the manufacturer as to their thoughts on the topic. Therefore our experience with acephate in 2011 is still a bit of a mystery to us. We had not seen such a problem with in-furrow liquid applications in any of our trials over many years. In contrast, Jay Chapin at Clemson University, a well-respected entomologist and peanut agronomist has always been cautious on use of Orthene in the seed furrow because of possible stand loss. His view on this carries a lot of weight with us. Will we see widespread stand loss in 2012 with Orthene in the seed furrow? We simply do not know.

Secondly, is our view of the new option, the Meymik, alidcarb product. Everything on the label is consistent with the label for Temik as far as the formulation, application techniques, and rates. There is one big question mark with the use of this product and that is that none of us have had an opportunity to field test it in Virginia or the Carolinas. The product will be manufactured outside of the US and shipped in. This is very different from the manufacture of Temik. That means this product could be as good as advertised or there may be some issues related to the many factors that can affect any new granular product (flowability, storage, purity, rate of seedling uptake, etc.). We simply do not know. We have no reason to doubt that it will perform well, but obviously we like to have data before we make recommendations and all of you go out and invest money in a product. There is one additional thrips control option that deserves mention and that is Admire Pro. Admire is a liquid formulation of the active ingredient, imidacloprid, the same ingredient that is used in the Aeris cotton seed treatment. Admire Pro is labeled for use in peanut as a liquid in-furrow application at 7 to 10.5 oz per acre. It performed very well in some 2011 field trials at 8.5 oz per acre providing excellent thrips control, good virus suppression, and yields that were competitive with the best treatments. We are still somewhat cautionary about sharing this information, as we have very limited data and experience with Admire Pro, but, it looks like it may be another good option to consider.

Our thoughts on planting in 2012 are that we are indeed concerned about what we saw with acephate and the delayed emergence. We observed the typical good performance that we always see with phorate products and prior to the possibility of an aldicarb product for 2012, our general consensus was to recommend applying phorate in the seed furrow at planting (with careful calibration, especially on sandy soils) and being ready for early postemergence applications of Orthene if additional thrips control is needed. The new Meymik product is an unknown. If you choose to use it, perhaps a good approach is to plant a portion of your acreage with this new product and make your own observations on how well it works for you. The same approach would be recommended if you consider using Admire Pro. Remember the old saying of not putting all of your eggs in one basket? We will work hard to develop a lot of data this year, but that is not going to help you make your decisions prior to planting. If we receive any updates between now and planting time, we will do our best to make them available

Article first appeared as North Carolina Peanut Note (PNNC-2012-001)