Farmers in the Midwest may be concerned about white mold (also called Sclerotinia stem rot) in soybean this year. The disease, caused by the fungus Sclerotinia sclerotiorum, is not common every year, but farmers who have battled the disease in the past will want to assess the risk of white mold development as soybeans approach flowering (growth stage R1 – plants have at least one open flower at any node).
Rust is a fungal disease caused by several species of Puccinia. All turfgrass species are susceptible to rust. However, it is most commonly seen on perennial ryegrass and Kentucky bluegrass.
From a distance, rust infected turf has a yellow-brown color. Close examination of rust-infected grass blades reveals numerous yellow-orange pustules. Rust can be easily diagnosed by walking across the lawn. As one walks across the lawn, bright orange spores of the rust fungus rub off onto one’s shoes.