SEED-BORNE AND SEED-TRANSMITTED FUNGI, ETIOLOGIC AGENTS OF DAMPING-OFF OF CASTOR BEAN

Castor bean (Ricinus communis L.) is susceptible to more than 150 diff erent microorganisms and is affected by several diseases some of which responsible for great economic harms. The purpose of this study was t o detect seed-transmitted fungi and to identify those pathogenics to t his crop. It was made seed health analysis and pathogenicity studies w ith the microorganisms detected under laboratory conditions, in Campin a Grande, PB, Brazil. Several fungi were detected in castor seed. Some are causal agents of serious plant diseases. Fusarium sp., Alternaria ricini, Aspergillus flavus and Chaetomium sp. caused seed rot and or lower germination. Fusarium sp., Rhizoctonia solani and Alternaria ric ini were transmitted by seed and caused severe seedling damping-off.