Biological control ofFusarium wilt of pigeonpea byPantoea dispersa, a field assessment

Abstract

Fusarium wilt is one of the major yield and growth-limiting factors of pigeonpea (Cajanus cajan). For an ecofriendly and sustainable management of such a disease, a novel mycolytic strainPantoea dispersa was evaluated against fungal pathogenFusarium udum that is known to be infecting the susceptible variety of pigeonpea (T-15-15), commonly prevalent in India. To study the efficacy ofP. dispersa as a biocontrol agent in comparison with chemical fungicide Bavistin and antifungal biocontrol agentTrichoderma Monitor WP was studied in both pot and field experiments.In vitro, P. dispersa inhibits the growth ofF. udum. In the pot experiment,P. dispersa the treated pigeon pea (T-15-15) seeds showed higher percentage of seed germination and decreased wilt incidence as compared to chemical fungicide; Bavistin and antifungal biocontrol agentTrichoderma Monitor WP treatments. Moreover, the root, shoot lengths and growth were also found to be higher. Due to high impact ofP. dispersa inin vitro condition on controlling theF. udum growth, further study was conducted in field in a wilt-stricken plot. These studies were repeated for three cropping seasons (2004/2007). The seed dressing byP. dispersa reduced wilt incidence (47%) during field trials, which is greater than Bavistin (41%) andTrichoderma Monitor WP (36%) treatments. HenceP. dispersa was proven superior toTrichoderma Monitor WP and Bavistin; which are used as commercialFusarium wilt control agents.