Agronomists with the Texas AgriLife Extension Service are suggesting that farmers who use glyphosate-resistant crops start expanding weed control strategies.
“We have a critical issue arising, in that common water hemp in Central and Southeast Texas and Palmer amaranth pigweed in the High Plains have started showing signs of resistance to glyphosate herbicides,” said Paul Baumann, Texas AgriLife Extension Service state weed specialist, in an agency report.
Weeds developing resistance to common herbicides require new tactics, according to Baumann.
“If all else is killed out but that one plant is different, that is the start of the problem,” he said. “One common water hemp plant could shed 400,000 to 500,000 seeds. So if that one weed is not killed, then later that year or the following year, there may be a whole patch of this resistant biotype of the weed.”
His recommendation is for farmers to return to using soil-residual herbicides along with the glyphosate products. Trifluralin (Treflan) and pendamethalin (Prowl) are two of the available products that could be used in cotton programs. Some other approved products that also are soil-active herbicides are Staple, Cotoran, Dual and Warrant.