Replanted soybeans and those near maturing cornfields may be especially at risk of invading pests, including loopers, bollworms and armyworms.
“Pests are starting to move out of corn that is drying down and into younger, healthier soybean fields,” says Robb Dedman, Arkansas crop consultant. “We are starting to see worm and looper populations increase, which is especially concerning for replanted soybeans that are younger and have not yet lapped.”
A combination of later-planted soybeans, due to June flooding conditions in many spots across the Delta, ample host materials and rapidly maturing cornfields, is resulting in an abundance of midsummer pests when much of the region’s crop remains susceptible to pest feeding.
I have seen a plethora of armyworms this year,” Dedman says. “With lots of dead grass and dead crop residue out there after flooding, there is plenty of food for armyworms right now, and they are thick in the fields I'm scouting.”
While many entomologists recommend defoliation thresholds of 40% pre-bloom and 20% post-bloom, Dedman says that may adjust based on economics of this year's soybean crop.
“You take a young soybean plant with 10 leaves on it and it doesn't take much insect feeding to reach 40% defoliation. There's a lot less vegetation for them to eat, so they can more quickly damage that plant's yield potential,” he says.
Dedman's thresholds also move lower the higher the commodity price.
“Where bean prices are right now, we have to protect every individual bean that we can and get them in the grain cart,” he says. “That's serious money in growers' pockets this year, and my growers have a low tolerance for pest damage.”
“You have to take armyworms out. They can absolutely devastate a crop within a day or so, because they can move across a field so quickly,” Dedman adds.
Relying on Intrepid Edge® insecticide for looper and worm control in soybeans also can help diversified growers rotate the modes of action they use on each acre, no matter their crop mix.
“Intrepid Edge breaks that pattern and helps us better maintain activity against these pests. The longer we can manage resistance, the better off we are going to be,” Dedman says. “When I make a recommendation, I'm using Intrepid Edge nine times out of ten. I want to get that really fast knockdown on loopers and worms, while taking it easy on our beneficial populations.”
Because most Mid-South growers rotate from soybeans to corn, rice or cotton, rotating modes of action is critical to resistance management. Intrepid Edge offers a distinct mode of action as the only Insecticide Resistance Action Committee (IRAC) Group 5 insecticide.
“Intrepid Edge is a good option to take pressure off the diamide chemistry, which is relied on heavily by cotton and corn producers,” says Kyle Colwell, Corteva Agriscience territory manager. “Intrepid Edge also provides two modes of action, providing growers with broad-spectrum control and extremely fast knockdown of Lepidoptera pests.”
Learn how Intrepid Edge® insecticide can help protect your profitability.
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