EFFECT OF Senna occidentalis DRY BIOMASS AND Penicillium oxalicum ON GROWTH OF MASH BEAN UNDER Macrophomina phaseolina STRESS
Charcoal rot disease caused by Macrophomina phaseolina (Tassi) Goid. is a highly destructive disease of mash bean [Vigna mungo (L.) Hepper] that causes significant yield losses annually. In this study, leaf dry biomass of Senna occidentalis [1, 2 and 3% (w/w of leaf biomass/soil)] and a biological control agent Penicillium oxalicum Currie and Thom were examined in a pot trial for their potential to improve growth of mash bean under biotic stress of M. phaseolina. M. phaseolina inoculation alone reduced shoot and root dry biomass by 19% and 67%, respectively. Soil amendments variably increased both shoot and root growth under biotic stress of M. phaseolina. There was 33–43% and 25–75%; 29% and 150%; and 38–43% and 34–125% increase in shoot and root biomass of mash bean due to different doses of S. occidentalis, P. oxalicum, and S. occidentalis + P. oxalicum, respectively, over positive control. Soil amendment with 3% leaf dry biomass of S. occidentalis combined with P. oxalicum significantly improved plant biomass as compared to rest of the treatments. This study concludes that soil amendment with 3% leaves of S. occidentalis either alone or in combination with P. oxalicum can be used for better crop growth of mash bean in M. phaseolina contaminated soil.