Pathogenicity of Rhizoctonia Isolates to Papaya in Hawaii. D. T. Yamamoto, Research Assistant, Department of Plant Pathology, University of Hawaii, Honolulu 96822. M. Aragaki, Plant Pathologist, Department of Plant Pathology, University of Hawaii, Honolulu 96822. Plant Dis. 66:1136-1137. Accepted for publication 3 March 1982. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-1136.

Based on morphological characteristics of vegetative hyphae, nuclear numbers, and hyphal anastomoses, 15 isolated obtained from papaya roots were in anastomosis group 4 of Rhizoctonia solani. Twelve of these isolates were pathogenic to papaya, killing 24.4–98.8% of inoculated seedlings. Fourteen binucleate isolates of Rhizoctonia were not pathogenic to papaya seedlings.

Keyword(s): Carica papaya, Ceratobasidium, Thanatephorus cucumeris.