Two Mid-South soybean producers have found a way to knock out glyphosate-resistant Palmer amaranth. Steve North and Charlie Yancey both broadcast a postemergence treatment of ET herbicide tankmixed with glyphosate.
Steve North mainly farms in Dyer County, Tenn. Last year, he used a postemergence application of ET herbicide tankmixed with Roundup on some of his pivot-irrigated beans. He was going after glyphosate-resistant Palmer pigweed when they were less than two inches tall.
“The tankmix worked really well, probably getting 95 percent plus control,” he says. “It also controlled morningglories, and Roundup took care of all the grasses. It worked well, and we didn’t have any lack of moisture due to the fact that we irrigate; my soybeans weren’t drought stressed and were actively growing.”
In addition to activity on small Palmer amaranth and morningglory, ET also controls small teaweed.
Quick control reported
“We saw pigweed and morningglory control within five to seven days,” says North, who, in addition to farming, works for Crop Production Services at the Bells and Wynnburg locations. “It sped up the activity.”
ET is effective against ALS, triazine and glyphosate-resistant species. The herbicide also allows for application flexibility, is rainfast within one hour and is tankmix compatible with many herbicides. It is effective in cool and wet conditions and is economical.
The postemergence ET/glyphosate tankmix is part of North’s comprehensive weed control program. He starts with a burndown with Roundup/Rifle and comes back with Authority MTZ plus Roundup or Gramoxone – usually Gramoxone.
“Then I go over the top with ET/Roundup on some of the acres,” he says. “Plus, I spiked the Authority with two ounces of metribuzin.”
Most of North’s conventional soybeans are farmed no-till. He drills on 10-inch spacings. “Our beans generally run from a maturity group 3.9 to a 4.9,” he says.
Charlie Yancey made a postemergence application of ET herbicide tankmixed with glyphosate to smoke glyphosate-resistant pigweed on one of his Mississippi farms.
“The tankmix did a real good job,” he says. “The pigweeds were anywhere from three to six inches tall. ET, which is a contact herbicide, pretty much got all the pigweed, but I probably should’ve used a residual like Sequence in combination with ET because some came back.”
Nichino recommends that ET be applied to weeds that are less than four inches in height for best results.
In addition to farming in the Mississippi Delta, Yancey farms in West Tennessee. He says the ET/glyphosate tankmix showed control within three days.
“The pigweed started dying real quickly,” he says. “It’s comforting to see quick control of a problem weed.
“We furrow-irrigate our full season beans, which helped out last year when it was hot and dry,” Yancey says. “ET still performed well during the hot season.”
Although Yancey’s soybean weed control program normally be-gins with a burndown, his first herbicide spraying on his soybeans last season was the ET and Roundup postemergence application.
“On that field, we didn’t use a burndown last year because we had to break the ground to smooth out the ruts resulting from the wet fall in 2009,” he explains. “After we applied ET/Roundup, I came back with only Roundup. The field right next to it where I didn’t apply ET, I also had to come back with Flexstar.”
Whether farming pivot-irrigated beans like North grows, or furrow-irrigated beans that Yancey grows, a postemergence application of ET plus glyphosate is an economical and effective tool for controlling some of this season’s toughest weeds.
Nichino America contributed information for this article.