Japanese Beetles In Fields Are Decreasing
LAMAR, MO.
Jill Scheidt, agronomy specialist with University of Missouri Extension, scouted corn and soybeans east of Carthage, near Highway 96 on July 20.
She observed corn in the hard dough and dent stages. Black layer, or maturity, occurs about 20 days after the dent stage. Data from Mississippi and Louisiana show the field drying rate from maturity, or black layer, occurs at about 0.6 percent per day until the grain reaches 15 percent moisture.
“No earworm or Japanese beetle feeding on kernels was seen,” said Scheidt.
Scheidt observed soybeans in the 4-5 trifoliate and beginning bloom stages.
“Less than 5 percent defoliation was seen on leaves for Japanese beetle, grasshopper and bean leaf beetle,” said Schedt.
The threshold level for any foliage feeding insect in soybean is 30 percent defoliation before bloom and 20 percent defoliation during or after bloom. Scheidt recommends scouting soybeans for podworms if they are in the bloom stage.
Threshold level for podworm in soybeans are one podworm per foot or when 5 percent or more pods are damaged.
“A little bacterial blight was seen on soybean leaves, most likely due to the recent warm, wet weather. New leaves are healthy and green so the disease has stopped spreading and fungicide treatment is not necessary. The hot, dry weather likely slowed the disease,” said Scheidt. ∆