Newly developed alfalfa varieties with resistance can provide fairly good protection from potato leafhoppers. But large numbers of the pest in a stand can still cause problems, warns Robin Wright, entomologist with University of Nebraska-Lincoln (UNL) Extension.
“All fields, including resistant variety fields, should still be scouted,” he says.
Potato leafhoppers are about 1/8” long, bright green and wedge-shaped. The insects can cause severe damage to alfalfa by injecting toxin into plants as they feed. The feeding results in a distinctive yellow or purple triangle shape at the leaf tip.
“First-year, spring-planted alfalfa fields are particularly attractive to and vulnerable to potato leafhoppers, as are fields planted last year,” says Wright. “In older fields, these insects are usually a problem on second and third cuttings.”
Using a sweep net is the only way to reliably scout for potato leafhoppers. For help in making treatment decisions, he recommends UNL’s Potato Leafhopper Management In Alfalfa.
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