By Clint Thompson
Vegetable producers and cotton growers are anxiously playing the waiting game with regards to the cotton jassid.
If and when the new insect threat arrives this spring could have a ripple effect on growers’ management plans.
Producers controlled the jassid last fall with sprays they were already applying for whiteflies. Growers usually do not apply insecticides for whiteflies during the spring and summer. If growers have to manage the jassid year-round, it could lead to resistance development in whiteflies.
“If we’ve got to spray for jassid in the spring when whiteflies are really low and we’re selecting for resistance, that could end up being a problem as well,” Stormy Sparks, University of Georgia (UGA) Cooperative Extension vegetable entomologist. “If you go from only spraying in the fall to spraying most of the year, you’ve got greater potential for resistance.
“It’s going to depend on how well they overwinter and how early they get into the crop; how quickly they reproduce. They have pretty good reproductive capacity. A lot is going to depend on how well they overwinter. We’re hoping this year was a worst-case scenario. They overwintered last year, weren’t a problem in the spring and they became a summer/fall program, kind of like whitefly. If they show up in the spring in large numbers, it’s not going to be good for vegetables, and it will be disastrous for cotton.”
Immediate Impact
The cotton jassid made its presence known this past year, impacting the region’s cotton crop and certain vegetables like okra and eggplant. If it is not observed in the spring, then growers won’t have to worry about the jassid until they start worrying about whiteflies.
“In the fall, we’re already spraying for whiteflies because we have whiteflies every fall. A lot of the products we use for whiteflies are controlling jassid,” Sparks said. “In the fall, it’s probably not a huge thing in vegetables. If it shows up in the spring when we’re not spraying for whiteflies, then we’re going to have to spray for jassid.”