Researchers from Ohio State University’s College of Food, Agricultural and Environmental Sciences are looking to collect samples of several weed varieties that are herbicide-resistant and could potentially pose problems for growers in the region, said Mark Loux, an Ohio State Extension weed specialist.
Loux is collecting the samples as part of an effort to track herbicide-resistant weeds that are beginning to show up in Ohio fields that have caused problems for growers in other states. The goal is to try to prevent the weeds’ further spread in Ohio.
At the top of the wanted list is Palmer amaranth, which is also known to many cotton and soybean farmers in the South as a “pigweed on steroids.”
Palmer amaranth, which is a glyphosate-resistant weed that has wreaked havoc for Southern U.S. growers, has now been found at several sites in Ohio.
“We are ideally looking for seeds from plants that survived a herbicide program that has typically provided effective control in the past, or repeated application of glyphosate or other herbicides,” he said.
Other weeds from crop fields the team is looking for include seeds from populations of johnsongrass, and pigweeds, such as redroot pigweed, waterhemp, and Powell amaranth.
A benefit of tracking these weeds is that the data can be used to track where problems are developing and try to stay ahead of them, Loux said.
“We can also use the data to raise awareness of the next problems growers could be facing,” he said. “Palmer amaranth is a huge problem in the South, and we want to let people know that it has been found here in Ohio.
“Waterhemp is increasing and spreading through the state as well,” he said. “And we’ve gotten some reports from growers that johnsongrass, which has previously been reasonably controlled, this year has become a problem for some Ohio growers.”
In addition to raising awareness, the researchers can use the data to develop management and control recommendations for Ohio growers, Loux said.
Signs that a resistance problem may be developing include patches of surviving weeds in a field that is otherwise free of weeds or an atypical appearance of plants due to regrowth following treatment with herbicide, he said.
The weed samples will be accepted until Oct. 30, Loux said, with a goal of emailing results to growers in February or March 2014.
The sample submission form can be found at http://go.osu.edu/W5z.
Source: Ohio State University.