Frogeye leaf spot in soybean.

LANDISVILLE, Pa. — Researchers from the Pennsylvania On-Farm Network discussed soybean diseases Sept. 21 at Penn State Extension’s Field Crop Clinic.

Extension educator Del Voight and plant epidemiologist Paul Esker run the On-Farm Network, which conducts research on commercial farms.

While much of Penn State’s work is done on small plots at its research farms, the On-Farm Network, funded by the Pennsylvania Soybean Board, allows for farm-scale research across the state.

For seven years, Voight, Esker and the network have focused on foliar diseases such as white mold and frogeye leaf spot. They also have been researching sudden death syndrome and brown spot. Voight and Esker have studied the combination of insecticide and fungicide treatments in fields.

Growers need to catch white mold early.

“It’s a disease we know that can knock back yield if everything comes together,” Esker said.

Fields with a history of white mold are at heightened risk of new outbreaks, so farmers should begin scouting these fields between the R1 and R3 stages.

One of the earliest signs of white mold is round globules that look like rabbit droppings and, despite the disease name, are black.

“If we are seeing black fruiting bodies, that’s probably going to be a tell-tale sign of white mold,” Esker said.

Farmers who find white mold should consult an Extension educator or crop adviser to develop a plan. Late-season sprays only sometimes provide an economic return.

“There’s going to be field sites where we only see a couple bushels’ difference, and depending on the compound you put out, the cost is going to change dramatically on that,” Esker said.

While white mold can be a thorny challenge, Esker is less concerned about brown spot.

Summer infestations were small and were confined to the bottom side of the plant.

“I don’t get worked up on brown spots if it’s staying in the lower canopy,” Esker said.

In addition to its disease work, the On-Farm Network has been working to get seed companies and farmers interested in soybean seed saving.

Widely used in Iowa, this practice allows for genetic testing in the offseason, Voight said.

Farmers can only save seed if the variety is off its patent and they have not signed a contract with their local seed dealer.

Pennsylvania farmers have been making similar yield gains to farmers in other parts of the country. Farmers’ willingness to spend on additional inputs will depend on the soybean price, the researchers said.

Special Sections Editor

Courtney Love is Special Sections Editor at Lancaster Farming. She can be reached at 717-721-4426 or clove@lancasterfarming.com


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