Implementing a Management Program for Sclerotinia sclerotiorum in Snap Beans

Abstract

Sclerotinia sclerotiorum white mold can potentially infect 100 percent of the snap bean acreage in New York State. The black seedlike sclerotia residing in the soil are the overwintering and survival structures of Sclerotinia sclerotiorum, the causal agent of white mold in snap beans and many other important commercial crops such as dry beans, cabbage, potatoes, alfalfa, and soybeans. If the soil conditions in a sclerotia-infected field are wet for approximately one to two weeks, the sclerotia can germinate to produce mushroom like structures which eject spores. If the spores land on susceptible tissue (bean blossoms in a snap bean field), and the weather remains wet or the field is irrigated, the bean tissue and pods can get infected with white mold. Reducing the number of sclerotia in the field can reduce the amount of inoculum available to infect susceptible crops and ideally reduce disease incidence and severity.