​Evaluation of Bio-control Agents and Organic Amendments for Managing Root Rot (Rhizoctonia solani) of Clusterbean (Cyamopsis tetragonoloba)

Background: Root rot of clusterbean [Cyamopsis tetragonoloba (L.) Taub.] caused by Rhizoctonia solani is an important menace and causes significant economic losses in India and chemical pesticides are mostly used to overcome this problem. As per environment and health issues and demand of organic produce, the current study aimed to find the most effective control measure of this dreaded disease through eco-friendly approaches. Methods: The present field-laboratory investigations were conducted during 2018, to evaluate four bio-agents in vitro and in vivo (Trichoderma harzianum, T. viride, Bacillus subtilis and Pseudomonas fluorescens) and five organic amendments in vivo namely wool waste (@ 50 q/ ha), human hair (@ 50 q/ ha), mustard cake (@ 5 q/ ha), castor cake (@ 6 q/ ha) and neem cake (@ 5 q/ ha) were evaluated. Result: Our investigations in vitro with bio-agents depicted that T. harzianum was highly inhibitory (62.65 %) followed by T. viride (48.52%). Seed-cum-soil application (6g/kg seed + 6kg/ha) of T. harzianum was found most superior in reducing disease incidence (74.03%) followed by Trichoderma viride (69.83%) while in organic amendments, neem cake (5 q/ha) was found highly effective (70.07%) followed by castor cake (64.40%), mustard cake, wool waste and least effective was human hair. Though, wool waste and human hair least effective in disease management but preliminarily results indicated encouraging response with dual action, one in reducing disease and another in increasing plant biomass that open the future scope of further more sustainable experimentations. The findings of this study can be utilized to manage the disease effectively and eco-friendly.