AgFax Cotton - Louisiana

By AgFax Media LLC,


Bollworm activity and treatments are gaining momentum.

Plant bugs continue to press cotton near corn and other hosts. 

Aphid populations have picked up in places, as have spider mites.

Except where they're in areas caught by drought, most of our contacts continue to talk about the heavy fruit load their cotton is holding.

A minor amount of target spot is turning up in places.


Sebe Brown, Northeast Louisiana Region Extension Entomologist:

"Calls this week have primarily been about bollworms, and we're still in the midst of an egg lay. Depending on the area, eggs are very light or very thick, from 5% to as much as 80%. The heaviest are mainly in proximity to corn.

"The 2-gene technology does seem to be holding. I'm seeing that in my plots and hearing that from other people in the field. That's better than how things evolved last year, and I haven't heard of anyone going out with oversprays. Where they have light egg percentages, guys are waiting to see what happens. A lot of them say they may not have to go over the top with a diamide, at least not this week.

"They're finding live worms but also are finding 1- and 2-day-old dead worms in the bracts, on terminals and in flowers. Where they're finding live worms, consultants say the worms look sick and aren't making it through.

"That's not the case in every field, although it's more the norm than the exception. At least for right now (7/17), we don't have quite the pressure on the technology that might cause problems, although that can easily change. But compared to this time last year, pressure is much, much lighter. 

"Spider mites are still kicking up in a few places. We did receive at least 3 inches of rain last night and today over a lot of areas in northeast Louisiana, which should help with spider mites. In places that missed rain, mites could start showing up. Temperatures are hot and we're using harsher chemicals, so that would favor mites."

Gary Wolfe, La-Ark Agricultural Consulting, Ida, Louisiana:

"Any rain lately has been spotty and people have been irrigating. Plant bugs are out there but seem reasonably light. I've gone with Diamond on pretty much everything.

"We saw a little bleed-through with this moth flight on the 2-gene cotton, and that mainly happened in ranker spots. In our area, soils vary pretty distinctly across fields from sand to clay, so we see spots with more growth where you get into sand. Where I'm finding worms, it's mostly in those spots. 

"I checked more than 3 hours on 1,600 acres on one farm and only found 6 worms, and they were in parts of the field where the canopy had closed. A lot of little bolls had shed but I never found worms where I pulled the dried bloom tags. Worms were hitting a lot of terminal fruit but were dying, and that was in the 2-gene Bt varieties.

"Of all of my growers with the 3-gene cotton, only one so far didn't want to go with an over-spray for worms. That cotton is holding so far. You'll see low-level damage under a pivot where the worm hit a boll but then it backed out and water got into the boll. In dryland cotton, I'm not finding that."