Biological control of chinese cabbage bottom rot and strawberry bud rot caused by Rhizoctonia solani

Abstract

Rhizoctonia isolates from strawberry were characterized for oprimum temperature of mycelial growth, nucleus number and anastomosis group. Biological control of chinese cabbage bottom rot and strawberry bud rot caused by Rhizoctonia solani AG2-1 were also tested using antagonistic microorganisms from soil. One multinucleate isolate (Stw001) was identified as R. solani AG4 by anastomosis analysis and nuclei staining. Three others binucleate isolates (Stw002, 3, 4) were identified as Rhizoctonia spp. Optimum temperature of mycelial growth of Stw-001, 002, 003, 004 and Rf1-0 was between 28-30°C, and AG2-1 was 23°C. Stw001 and AG2-1 were pathogenic to chinese cabbage and strawberry. Sixty two microorganisms (167 isolates) inhibited mycelial growth of R. solani AG2-1 and AG4, and two isolates (Kr013 and Kr020) of 68 antagonistic microorganisms had a suppressive effect on disease development of chinese cabbage bottom rot and strawberry bud rot caused by R. solani AG2-1 or AG4 when applied as a seed treatment or as a planting hole treatment with a charcoal carrier.