What is in this article?:
- Controlling cotton insects early can pay dividends
- Adding pyrethroid boosts effectiveness
- No changes in insect susceptibility to Bt
Controlling cotton insects early, particularly plant bugs, can pay, says Angus Catchot, Mississippi State University associate Extension professor of entomology and plant pathology, who spoke at the annual Delta Ag Expo at Cleveland, Miss.
Adding pyrethroid boosts effectiveness
As cotton begins blooming, he says, adding a pyrethroid to organophosphates provides better control, plus offering a safety net for control of escaped worm eggs.
Planting date can also be a factor in insect control, Catchot says.
“Growers have long been told that managing for earliness can help avoid late-season buildups of resistant worms. Now, we’re seeing the same situation with plant bugs — that early planting results in higher yields and fewer insecticide applications for tarnished plant bug.
“If you can plant in the April 15-May 1 window, it may save applications on the back side. In our trials, we’ve reduced applications as much as 60 percent just by planting early.”
Growers should also consider applying ULV malathion plus a pyrethroid in the end of July/August period, he says. “Using this mix in rotation with other materials late season can, we feel, make a difference in plant bug control and offer another option not currently being utilized for control of the pest.”
Although 80 percent of insecticide applications on cotton are made by air, Catchot says, “we’ve seen some eye-opening differences in control for ground application, and in many cases probably could have made one less application. It will be important to focus on water volume and tip selection, particularly late in the season when cotton gets rank.