Seed Treatment with Bacterial Antagonists - A Simple Technology to Manage Groundnut Root Rot under Residual Moisture Conditions

Abstract

Seed treatment with talc based formulations of 11 bacterial antagonists was carried out to study their biocontrol activity against the root rot pathogen Macrophomina phaseolina and growth promotion in groundnut under residual moisture conditions during 2007 and 2008. Various growth parameters and incidence of root rot in different antagonist's treatment were recorded. Difference in the plant stand, increase in growth parameters at 60 days after treatment was insignificant. High rhizosphere colonization was reflected from the high population of RP6, IISR-6 and consortium of EB69+RP7, EB69+RBh42a, RP7+RBh42a obtained 60 days after treatment. Seed treatment with RP2, EB69 during 2007 and EB69+RBh42a, RSh5 during 2008 recorded the highest plant stand at the time of harvest. Least incidence of root rot was recorded in EB150 (9.26%) and in RSh5 (19.40%) during 2007 and 2008, respectively. EB150 reduced the incidence of root rot by 70% and increased the yield by 46% during 2007. RBh42a reduced the incidence of disease by 40% and increased the yield by 137% during 2008. Other bacterial antagonists also reduced root rot incidence and increased pod yield considerably. Based on this study it is concluded that a simple seed treatment with potential antagonistic bacteria during sowing would reduce the incidence of root rot and improve the yield in groundnut under rainfed conditions.