AgFax Cotton - Louisiana

by AgFax Media LLC,


Pest pressure has picked up through much of the Midsouth.

Plant bug numbers are increasing in places. While this is still mostly considered a light to moderate plant bug season, the counts are building in more areas.

Bollworms also have increased through a wider part of the region. Enough are in the system to prompt treatments across most technologies, although the main focus is on some of the more susceptible varieties.

The prolonged and intense heat – coupled with lack of rain in places – has skewed insect patterns. Aphids are lingering and spider mite applications continue. See comments by Louisiana's David Kerns.

Irrigation systems are running nearly 24/7 on many farms, so it's a logistical challenge at times to make pest treatments.


Gary Wolfe, La-Ark Agricultural Consulting, Ida, Louisiana: "We're in a pretty big moth flight and are trying to get out ahead of any worms. So far, we're not finding worms but are seeing moths. Pyrethroids are going out for worms on most of the Phytogen and WideStrike. One grower opted to go with Besiege and Diamond to stretch out control a little longer.

"We're holding off on treating all the Stoneville and the WideStrike 3 and then will see what happens. Plant bugs were quiet for a while, although they are starting to pick up. In the Stoneville cotton we can't find enough plant bugs to amount to anything, so we don't have an immediate need to treat it."

Richard Griffing, Griffing Consulting, LLC, Monterey, Louisiana: "On average, our cotton is in mid bloom and moving along fairly rapidly. I expect to find my first open boll in 7 to 10 days (from 7/18) in cotton planted around April 2-3. Most of my cotton, though, isn't that far along.

"Spider mites are very persistent right now. The same goes for plant bugs. We're having more trouble, as well, with bollworms in Bt cotton, especially in the WideStrike. They're giving us fits, even where we've oversprayed with Prevathon. We're finding tremendous numbers of bollworms in general and are having varying degrees of trouble with them across all varieties. But it's been more intense in the WideStrike.

"We've come back with pyrethroids in some fields, but we just have overwhelming numbers of bollworms. All we've applied in the non-WideStrike varieties is a pyrethroid, with 3 sprays on the regular BollGard. It's holding pretty well."

David Kerns, Entomologist, Louisiana State University, Macon Ridge Research Station: "It's very hot and dry and has been that way for a while. Any dryland cotton out there doesn't exactly look happy right now. Even the irrigated cotton is stressed in places. We'll possibly move into triple digits this week for the high temperature, so things won't get any better. If we're lucky enough to catch some afternoon showers, that might at least help.

"Stressed cotton like this lends itself to more pest problems. The expression of the Bt toxin falls off, so you end up with more bollworms and fall armyworms than you'd have with cotton that's healthy, lush and actively growing. Bollworms are coming through more than might be expected, plus I'm hearing reports about fall armyworms (FAW) breaking through.

"Several consultants have reported picking up some larger FAW in their cotton. I haven't seen FAW come through Bt cotton since I've been in Louisiana, although it was somewhat common in Texas where they have more FAW pressure. We are dealing with heavier FAW numbers, in fact, than we've seen in at least a couple of years. But a lot of these breakthroughs still reflect the stress this cotton is under.

"These hot, dry conditions also favor spider mites, and I can go into just about any field right now (7/19) and find mites. Be very cognizant that mites are present and try to avoid using any materials that might aggravate them if you treat other pests.

"Even aphids seem to be hanging on this year, and that also might be attributed to this intense heat and lack of rain. We're not seeing much of the fungus that should be taking out aphids. Since plant bugs also are on the increase, consider materials with activity on both plant bugs and aphids.