Bio-efficacy of Pseudomonas fluorescens (7% WP and 5% SC formulations) against bacterial wilt disease of chili

Abstract

Bacterial wilt caused by Ralstonia solanacearum is an important disease of chili crop in West Bengal. P. fluorescens was employed to manage R. solanecearum under field condition. The combined use of seed and soil treatment were most effective (0.83 to 10.82% PDI) than sole use of seed or soil treatment (3.33 to 24.98% PDI). Vegetative growth and yield of chili were also influenced through integration of seed and soil treatments with P. fluorescens 7% WP @ 10 g/kg seed + 2.5 kg/ha as well as with P. fluorescens 5% SC applied @ 10 ml/kg seed + 2.5 lit/ha . The seed treatment when followed by soil treatment showed best result in respect of fresh root weight (6.63-7.43 g), dry root weight (2.53-2.80 g), fresh shoot weight (55.45-60.23 g), dry shoot weight (24.25-26.33 g), plant height (44.83-47.53 cm) and yield (257.18-265.60 kg/ha) than control. There was no adverse effect of P. fluorescens 7% WP and P. fluorescens 5% SC on soil beneficial microbes. The products increased the root and shoot weight, dry weight of seedlings and seedling vigor index than control. The per cent root colonization in sterilized and non sterilized soil was in the range of 80-89%.It may be concluded that, the combined application of P. fluorescens 7% WP as seed treatment @ 10 g/kg seed + soil treatment @ 2.5 Kg/ha or P. fluorescens 5% SC as seed treatment @ 10 ml/kg seed + soil treatment @ 2.5 lit/ha is suggested for effective management of bacterial wilt of chili. Keywords— Chili, wilt, Ralstonia solanecearum , Pseudomonas flurorescens , biocontrol.