EVALUATION OF NATIVE ANTAGONISTS FOR THE MANAGEMENT OF STEM ROTS OF CLUSTER BEAN CAUSED BY SCLEROTIUM ROLFSII SACC.

Abstract

Cluster bean, Cyamopsis tetragonoloba (L.) Taub is an important annual legume crop of kharif season in arid and semi-arid regions of the Indian subcontinent. Six fungal antagonists and four bacterial antagonists were evaluated against Sclerotium rolfsii in vitro and in vivo condition to develop an effective management strategy for stem rot of cluster bean. During in vitro studies, native fungal and bacterial antagonists were inhibited the mycelial growth of pathogen. Among the fungal antagonists tested, the isolate-I4 (THM) showed the maximum growth inhibition of S. rolfsii up to 68.10 per cent. The bacterial antagonist Isolate-I3 (PFV) recorded the maximum inhibition zone of 13.33 mm and a minimum of 23.00 mm mycelial growth of S. rolfsii. Pot culture studies revealed that the combined application of T9-T. harzianum (THM) + P. fluorescens (PFV) (ST+ SA) through seed treatment and soil application recorded the minimum incidence of stem rot (4.66 per cent) and maximum plant height, number of pods/plant and pod length.The findings reported in the present study supported the applicability of isolate-I4 (THM) Isolate-I3 (PFV) as a possible alternative to fungicides for the control of root rot in black gram.