Controlling Nematodes: Microscopic Worms a Focus of Cotton Producers

Clint Thompson Cotton, Georgia

UGA photo/Shows a cotton plant damaged by nematodes.

Cotton planting season is still a month or two away for producers in the Southeast. But it is never too early to start planning for nematode control. After all, once producers close the furrow during planting, they have done all they can do to protect their crop, says Bob Kemerait, University of Georgia Cooperative Extension plant pathologist.

“Once you close the furrow, basically you’ve got to sit on the sidelines and watch the game from the sidelines, the nematode sidelines after that,” Kemerait said.

Nematodes are microscopic worms that can be devastating to cotton and other row crops. Root-knot nematodes cause the most problems because of their wide host range. Cotton roots can swell if infected by the southern root-knot nematodes. The knots serve as feeding sites where the nematodes grow, produce more eggs and stunt the plant’s growth.

The best management strategy that growers can implement is to use resistant varieties, though some growers might be hesitant.

“If they’re not going to use resistant varieties, make sure they look at the nematicides that are out there and see which one is appropriate for the level of threat that they have and what they’re prepared to do,” Kemerait said. “I’d love for them to consider resistant varieties. That’s the cheapest way for them to get nematode control, but not every grower wants to grow those varieties. If they’re not going to, it’s important they make sure to choose the right nematicide. Or they can do nothing and sit on the sideline and watch the game get away from them.”

Nematodes Are Active

Kemerait said he took a soil sample in Colquitt County (two weeks ago) and the nematode population was over threshold and still active in the soil.

“The nematodes have not gone anywhere. They are there. The only ones that have gone away are if you are rotating away from cotton this year and going into something like peanuts, then it’s going to help you,” Kemerait said. “Otherwise, those nematodes are going to be there. They’re waiting.”

About the Author

Clint Thompson

Multimedia Journalist for AgNet Media Inc.