Detection of root-rot pathogens in seeds of cluster bean [Cyamopsis tetragonoloba (Linn.) Taub.]

Detection of the root-rot pathogens Fusarium solani and Rhizoctonia solani in cluster bean seeds, populanly known as guar seeds (Cyamopsis tetragonoloba (Linn.) Taub.), was attempted using standard blotter and agar plate methods. Blotter method seemed better, where 30 per cent seeds showed root rot pathogens, of these 17 per cent had colonies of F. solani and 13 per cent had R. solani. In agar plate method, 19 per cent seed showed root rot pathogens, and frequency of F. solani and R. solani was 10 and 9 per cent, respectively. The site of infection of both the pathogens was the seed coat. The sections of infected seeds of guar showed the presence of inter and intra-cellular mycelium of the two pathogens, and sclerotia of R. solani in seed coat and cotyledons.