Effect of crop rotation and cultivar resistance on bacterial wilt of tomato in Nepal

The effect of crop rotation and cultivar resistance on bacterial wilt of tomato (Lycopersicon esculentum), caused by Ralstonia solanacearum (biovar 3 and race I), were studied from 1994 to 1996 in a field experiment in Chitwan, Nepal. Corn (Zea mays), lady's finger (Ahelomoschus esculentum), cowpea (Vigna unguiculata), and the partially resistant tomato line CL1131-0-0-43-4 (CL1131) were rotated with susceptible tomato in different combinations. The susceptible tomato cultivar Pusa Ruby was used as an indicator plant to assess wilt severity (percent leaves wilted) in each plot after rotation. Wilt severity was significantly (P < 0.05) reduced by rotation with corn, lady's finger, cowpea, or resistant tomato compared with continuous tomato. The onset of bacterial wilt was delayed by 1-3 weeks and wilt severity was reduced by 20-26% when susceptible tomato was grown after corn, lady's fingers, cowpea or resistant tomato. Lower area under the disease progress curve (AUDPC), based on wilt severity, and higher...