Farmers must sometimes feel like they in a war with a weed. Palmer amaranth has now developed full-on resistance to glyphosate products and the weed can now hold its on in fields formerly protected by a product growers once relied on nearly exclusively, if not completely. Now those farmers realize they have a whole new set of challenges to contend with.
Weed resistance is a huge deal. N.C. State weed scientist Alan York once noted, for example, resistant Palmer had the potential to shut down the cotton industry in the Southeast. Hopefully, since then, growers have taken his oft-repeated advice and learned to respond to Palmer with a number of strategies.
York was one of the speakers, Aug. 9, at the Mount Olive, N.C., stop on Bayer CropScience's Respect the Rotation Tour. The tour has been making stops across a large part of the U.S., including Illinois, Minnesota, Nebraska and North Carolina. Joining York in Mt. Olive were Wesley Everman, a NCSU assistant professor with primary responsibilities that include weed management in corn, soybeans, small grains and bioenergy crops. Also on hand was Charlie Calhoon, a graduate student working under York, and doing work focusing on weed-resistance in cotton.
One reason Bayer mounted the tour is to point out the company's current and new technologies can help growers join the weed-resistance fight. This technology, company spokespersons say, will "preserve the utility of glyphosate" while boosting growers effectiveness in the glyphosate-resistance battle.
On a practical level, how should growers proceed? Bayer says they should rotate modes of action and use multiple modes of action to reduce selection pressure on various products. They should also rotate non-permanent crops Growers should also closely scout their fields and give particular attention to problematic areas, use tillage or a burn down herbicide program, make precise herbicide applications, reduce the seed bank by not allowing surviving weeds to set seed, control escapes and use clean equipment.
You can learn more about the recent Respect the Rotation tour by visiting the Bayer CropScience web space.