Effect of Temperature on Virulence ofRhizoctonia solaniand OtherRhizoctoniaon Potato

Pathogenicity of 47 isolates from various geographical locations and host plants representing 11 of the 12 known anastomosis groups of Rhizoctonia solani and 12 isolates representing other multinucleate and binucleate species of Rhizoctonia was determined on sprouts and roots of emrging potato plants at 10, 15.5, and 21.1 C. Isolates of R. solani AG-3 killed significantly more sprouts than any other group. Isolates of most groups killed no sprouts. Whereas isolates of R. solani AG-3 and AG-5 damaged sprouts significantly more than other groups, most damage to roots was caused by isolates of R. solani AG-8 and AG-3 (...)