Studies on sharp eyespot disease of cereals II. Viability of sclerotia: persistence of the causal fungus, <i>Rhizoctonia solani</i> Kühn

Abstract

SUMMARY Sclerotia of Rhizoctonia solani survived for long periods in the laboratory. When left undisturbed in the soil, 79% of buried sclerotia survived for a period of 6 months. Sclerotia retained their infectivity towards seedling wheat plants throughout all viability tests. Sclerotia germinated readily in response to various stimuli and were able to regerminate at least ten times: it is considered that this property enhances their survival value. Although wheat stem isolates decomposed cellulose in pure culture and competitively colonized certain types of cellulose in soil, they were ineffective in colonizing cereal straws in the soil. The pathogen quickly died out in artificially infested soil and showed only limited survival in naturally infected cereal straw buried in soil. In pot experiments the pathogen persisted parasitically under a number of crops.