How Managing Herbicide Resistance Is Not Futile for Crop Protection Companies
It has been 40 years since a new weed-killing chemical mechanism has been introduced into the crop protection marketplace, writes Douglas Guth at CropLife. The decades since have seen weeds become resistant to existing herbicides, resulting in these problematic plants escaping growers’ best efforts to neutralize them.
“We’ve been giving weeds a herbicide diet, and they keep finding ways to get around that diet,” says Ron Geis, a Market Development Specialist with Corteva Agriscience. “There’s been nothing waiting in the wings when one process fails, so herbicides should have multiple modes of action to keep weeds off balance.”
As weeds are staving off typical glyphosate herbicides, agricultural chemical companies like Corteva are developing new modes of action that target invasive plants before their tolerance can evolve. New herbicide combinations should sustain product life and limit the overuse of pesticides in the battle against resilient weeds, says Geis.
Companies are increasing their R&D efforts to create handy formulations, offering varied solutions that can tackle farmer pain points this year and down the road. Corteva’s Vorceed Enlist, for example, is a corn rootworm stopper with the added benefit of curtailing late-season emerged broadleaf weed pressures. Enlist’s corn trait overcomes weed tolerance to 2,4-D choline, glyphosate, glufosinate, and FOP herbicides.
When applied according to label instructions, Enlist solutions feature near-zero volatility as well as reduced potential for physical drift. A wide application window further enables the use of Enlist in the mitigation of late-season broadleaf weeds, says Geis.
“Our Resicore herbicide is good for corn as well,” says Geis. “It has three modes of action to manage weed resistance. Combining Resicore with other resistance products gives farmers a wide application window throughout the operating season.”
Ongoing U.S. drought conditions accentuated the importance of multiple applications and modes of action. Additives included in existing herbicides increased uptake in moisture-deprived weeds where closed stomata and thickened cuticles had reduced product effectiveness. Corteva also emphasizes attacking post-emergent weeds like water hemp when at small stature, or about one to three inches in height.
Riding a successful 2023 into a full launch next year is Kyro, a corn herbicide combining three modes of action effective against 65 different types of broadleaf and grass weeds.
Read more at CropLife.