Prevalence and management of tomato bacterial wilt using selected resistant varieties in Morogoro Region, Tanzania

Dissertation in Crop Science 2019Bacterial wilt disease is a very serious problem to Tomato growers of Morogoro region. The objective of this study was to identify the status and pathogenicity of Ralstonia solanacearum causing Tomato bacterial wilt disease in Morogoro region. Most of the farmers 71.7% had a farm of less than 1 ha. Majority of the farmers 32% were growing both hybrid and OPV while the reasons for variety preference differed across the villages. Most of respondents 79% were knowledgeable with the disease and considered uprooting affected plants as the only major control measure on the disease. Most of the farmers 35.5% neither burn nor bury the remains of uprooted infected plants and the remained 32.6% bury while 31.9% burn the crop remains. The results showed the highest disease incidence and severity were 42.32% and 3.1 recorded in Kiberengeni and the lowest were 13.76% and 1.75 Nyandira respectively. Majority of the farmers are using seedbed and furrow irrigation system contrary to seedling trays and drip irrigation system. Assila F1 recorded the lowest disease scores, then Rio safari variety while Cal J recorded the highest. Root drenching+wounding inoculation technique recorded significantly highest disease scores and was fatal compared to the other inoculation techniques. Most of Tomato growing farmers84.8% don’t manage the disease properly in Morogoro. Equipping farmers with knowledge of good agronomic practices will enhance proper management techniques of the disease. The use of certified and disease free seeds, resistant or tolerant varieties, good agronomic practices can help in proper management of the disease across Morogoro region. The bacterial inoculum isolated from Morogoro was confirmed as R. solanacearum using biochemical tests, Serological test and pathogenicity test. From above such results it was observed that Assila F1 tomato variety was significantly resistant compared to Rio safari and the susceptible Cal J. The use of Asilla F1, followed by Rio safari variety with proper agronomic methods can help farmers to minimize the disease new infections and ultimately spread