Management of bacterial wilt disease of potato in coastal plains of Odisha

Bacterial wilt and brown rot caused by Ralstonia solanacearum is one of the most dreaded diseases causing 30 to 70% yield loss in India. The disease is both tuber and soil borne. A field trial was conducted following split plot design in the year 2008 to 09 and 2009 to 10 under All India Co-ordinated Potato Research Project in Central Farm, Orissa University of Agriculture and Technology, Bhubaneswar, Odisha, India with chemical soil amendments in main plots (M1 = application of bleaching powder 7 days prior to planting, M2 = application of bleaching powder at the time of planting, M3 = no bleaching powder application) and different physical, chemical and bio-agent treatments in the subplots (T1 = large sized tuber, T2 = tuber treatment with Bacillus subtilis (106 cfu/ml),T3 = tuber treatment with boric acid, T4 = tuber treatment with Bacillus subtilis + boric acid, T5 = tuber treatment with streptocycline (0.015%), and also 4 times basal drenching with streptocycline (0.015%), T6 = control). Observations on plant wilt at 75 days after planting and yield of healthy and rotten tubers at harvest were recorded. Soil application of bleaching powder at the rate of 12.5 kg/h irrespective of other treatments significantly reduced wilting of plants in comparison to control. Among the treatments, tuber treatments with streptocycline combined with basal application of the same antibiotics at 10 days interval for four times after planting resulted in minimum wilting (3.83%) of plant and significant increase in tuber yield (18.21t/h) followed by tuber treatment with B. subtilis along with 3% boric acid (17.31t/h) recoded to be the second best treatment in reducing the wilting (9.55%) and increase in yield over control.