Bacillus spp. mediated management of soil borne diseases in Gloriosa superba L.

Abstract

Gloriosa superba crop was found to be affected by two soil borne diseases viz., stem rot/root rot/tuber rot caused by Macrophomina phaseolina and tuber rot caused by Sclerotium rolfsii. Among the seven Bacillus spp. tested against M. phaseolina revealed that B. amyloliquifaciens recorded significantly higher per cent of mycelial inhibition (53.33) followed by B. endophyticus (48.89) inhibition over control. Among the different dipping concentrations tested, dipping the tubers in talc based formulation of B. amyloliquifaciens @ 1% was found to be effective in reducing the Macrophomina incidence to 16% and Sclerotium disease incidence to 36% as compared to control (72%). Pot culture studies on the management of tuber rot revealed that dipping tubers in talc based formulation of B. amyloliquifaciens @ 1% for 20 min. + soil application of talc based formulation of B. amyloliquifaciens in FYM @ 100g/plant on 30 and 60 days after planting was found to be effective in reducing the disease incidence to 40% with dry seed yield of 45.6 g/plant as compared to control (100% and 14.6 g/plant, respectively). The same treatment was effective under field condition and recorded the lowest incidence of Sclerotium (16%) and Macrophomina (14%) with the seed yield of 420 kg/ha as compared to untreated control (60% disease incidence and seed yield of 360 kg/ha). The population of Bacillus was maximum (10x 10−8 cfu/g) in treated plot soil after harvest as compared to untreated control (3 x10−8 cfu/g).