Evaluation of bio-control agents for management of dry root rot of chickpea caused by Macrophomina phaseolina

Dry root rot of chickpea caused by Macrophomina phaseolina is an important disease affecting chickpea production areas in India, the largest producer of this crop in the world. The disease is primarily controlled through the use of fungicidal seed treatments. In this study, several isolates of two bio-control agents, Trichoderma viride and Pseudomonas fluorescens, were assessed for their ability to reduce the growth of M. phaseolina under laboratory conditions and subsequently used for field studies. The most effective isolate of each bio-control agent and the commonly used chemical seed-treatments, carbendazim and hexaconazole were evaluated. In addition to the use of the fungicides and bio-control agents individually as seed treatments, the study also included a trial combining soil application through bio-agent enriched farm-yard manure, along with seed treated with the bio-control agent. It was found that this combination showed maximum germination, least root rot incidence and highest yields as compared to the other biological or chemical seed treatments included in this study. This paper reports the identification of native isolates of T vi ride and P. fluorescens that can be used under field conditions to control dry root rot of chickpea in tropical regions and demonstrates the use of a method of application that could significantly improve the efficacy of disease control while using bio-control agents. (C) 2012 Published by Elsevier Ltd.