Clemson grain specialist studies new sorghum technology for weed control

Weed control is a problem for grain sorghum growers and a Clemson researcher is determining if a new technology can help South Carolina growers knock out weeds and give growers a new variety.

Alex Coleman, Clemson University Cooperative Extension Service Small Grains and Sorghum specialist, is testing a new sorghum, Double Team (DT), from Sorghum Partners.

"I was getting questions from growers about what this new sorghum was and if it worked," Coleman said. "I'm testing it so that I can answer those questions."

According to developers, Double Team sorghum contains a trait added by conventional breeding practices that works with FirstAct herbicide to control grass weeds. FirstAct contains the active ingredient Quizalofop.

"There are other herbicides with the same active ingredient," Coleman said. "But, according to the technology-use agreement, growers can only use FirstAct."

Non-GMO crops and weed control

Sorghum is a water-efficient, non-GMO, gluten-free crop commonly used as livestock feed in the United States. Coleman is looking at how DT technology controls stubborn grass weeds like Texas panicum. Other objectives of Coleman's study include determining yield potentials of varieties containing the DT trait and how these varieties handle southeastern United States disease pressures.

"Weed control is a main problem that farmers contend with in non-GMO crops," said Coleman, who graduated from Clemson with a master's degree in plant and environmental sciences and a bachelor's degree in agricultural mechanization and business. "With sorghum being a grass, it can be difficult to use herbicides to control grass weeds without injuring the sorghum crop."

According to the FirstAct label, growers can make two applications during the growing season in South Carolina. So far, the herbicide appears to be doing its job.

"We've just had to apply the herbicide one time to the crop," Coleman said. "We're waiting to see if we will need a second application."

Yield drag, or yield reduction, is another factor Coleman is looking at.

"My concern with yield drag is often when a new trait is introduced, it is at the cost of another trait, which is sometimes yield or disease tolerance," Coleman said. "This year, I'm able to compare a Double Team variety to a traditional variety, side by side in the same growing conditions."

Most of the United States grain sorghum is grown in Kansas, Texas and Colorado. Current varieties are targeted for environments in these states. Southeastern states have higher moisture and humidity, as well as higher disease pressure.

Coleman's study will help determine if sorghum containing the Double Team trait can be profitably grown in the southeastern region. Coleman estimates 15,000 to 20,000 acres of grain sorghum are grown in South Carolina.

"What we're looking for in this study is to make a challenging crop easier to grow and give South Carolina farmers a new crop for their portfolios," Coleman said.

This is the first year of the study, which is taking place at several South Carolina locations. Information about this study will be posted at https://bit.ly/CU_GSVT.

Effects on livestock

Sorghum is a major feed grain for livestock. Herbicides must receive approval by the Environmental Protection Agency before they can be registered for use by the public.

All pesticides used on feed grains and forage crops must go through a strict approval process.

"The FirstAct product label has a 45-day harvest and a 45-day grazing restriction," said Brian Beer, a Clemson Extension Livestock and Forages agent. "This means the required testing and screening to establish a harvest restriction interval was conducted, and interval was approved by the Environmental Protection Agency."

Commercial animal feed products manufactured or distributed in South Carolina are vetted by the South Carolina Department of Agriculture's Feed Safety Program.

-END-