A set for Rhizoctonia solani isolates and another set for binucleate Rhizoctonia solani -like fungi are also available. This pathogen survives in soil within diseased host material or as sclerotia. It can persist in soil for years, especially since so many plants are hosts. When bean seeds are planted into infested soil, the fungus attacks the young radicle or hypocotyl of the emerging seedling. In moist environments, seedlings are rotted and killed while surviving seedlings have root or collar rots.
Rots develop on pods formed close to the ground.
Inoculum splashes on these pods and circular rots are caused by the pathogen. Sclerotia form in diseased host tissue and remain viable in soil. The pathogen is transported in infested soil or through movement of diseased plants or bean pods. Potential for seed-borne inoculum also exists. Obtain high quality seeds and avoid seeds that may be contaminated with the pathogen.