Effect of safe chemicals and bleaching powder on bacterial wilt incidence in Tomato caused by Ralstonia solanacearum race 1 bv. 3

In vitro, calcium chloride, sodium carbonate, sodium bicarbonate and bleaching powder at 0.25, 0.50, 0.75 and 1.0% concentrations were added separately in CPG medium. Minimum population of Ralstonia solanacearum 5.89 log₁₀ cfu/ml was found in 1.0% bleaching powder containing CPG medium followed by 5.91 log₁₀ cfu/ml of calcium chloride (1.0%). In vivo study, calcium chloride @ 0. 1 and 0.25% and bleaching powder @ 0.025 and 0.050% were mixed in soil containing vermiculite, peat moss and sand in ratio of 2:1:1, subsequently inoculated 50 ml 48 hrs old culture of R. solanacearum in each pot and transplanted 5 plants of 21 days seedling of tomato under glass house conditions. Minimum disease incidence (47.5%) was found in calcium chloride (0.1%) followed by bleaching powder (0.025%) after 9 ^th day of inoculation. The bacterial wilt disease was reduced by 50–52.5% by applying these chemicals. Population of R. solanacearum was drastically reduced 45.9% in rhizosphere of tomato in bleaching powder treated soil as compared to control.