By Clint Thompson
Scouting for plant bugs is an important practice all cotton growers need to be doing now, says Phillip Roberts, University of Georgia Cooperative Extension entomologist.
He estimates 35% to 40% of the cotton crop is squaring. Unfortunately, some farmers are already reporting high incidences of plant bugs.
“We have received a few reports of fields exceeding threshold for plant bugs. It does seem that these higher infestations are on our older cotton, cotton which is at least 10 or 12 nodes. In most years we only treat about 10% of our acres for plant bugs, and it’s the scout’s job to figure out which fields these are and need to be treated for plant bugs,” Roberts said. “Over the last several years, we have noticed a trend for early planted cotton to be at higher risk for plant bug infestations. It’s important you get out there and scout all fields that are squaring and treat bugs in a timely manner if thresholds are exceeded.
He added that fields should be treated if plants are retaining less than 80% of small squares where plant bugs are present.
Growers can utilize a sweep net to sample plant bugs. The threshold with a sweep net during the first two weeks of squaring is 8 plant bugs per 100 sweeps. The threshold is raised to 15 bugs during the third week of squaring.
“Our goal is to retain at least 80% of first position fruit when we enter bloom. Fields with 80% first position retention at first bloom still have maximum yield potential,” Roberts said.
Roberts emphasizes though that growers should not treat fields unless necessary.
“We need to maintain beneficial insects to suppress pests such as corn-ear worm, spider mites, aphids and whiteflies,” Roberts said.