EFFECTS OF SOIL AMENDMENT ON BACTERIAL WILT CAUSED BY RALSTONIA SOLANACERUM AND TOMATO YIELDS IN ETHIOPIA

摘要

Field experiments were conducted in Ethiopia to evaluate the effect of silicon fertilizer and sugarcane bagasse on tomato bacterial wilt (Ralstonia solanacearum). Silicon fertilizer significantly reduced the bacterial population, mean wilt incidence, percent severity index, and corresponding areas of disease incidence, and severity progress curves in the moderately resistant tomato cultivar (King Kong 2). Similarly, sugarcane bagasse resulted in a significant reduction of mean wilt and percent severity index, the corresponding areas under disease incidence and severity progress curves and the bacterial population at 5 days post inoculation, compared to the control, in cultivar King Kong 2. However, neither silicon fertilizer nor sugarcane bagasse resulted in any significant reduction of all disease parameters in the moderately susceptible cultivar Marglobe. Silicon fertilizer and sugarcane bagasse amendments also increased fruit yield for cultivar King Kong 2, but not for cultivar Marglobe. The total silicon content was also significantly increased in silicon fertilizer amendment, followed by sugarcane bagasse amended plants. The study recommends use of silicon fertilizer as a soil amendment under field conditions to augment resistance in moderately resistant cultivars where bacterial wilt disease problems prevail. However, a silicon fertilizer or silicon source was not found to substantiate or improve a susceptible cultivar. Sugar-cane bagasse was demonstrated to possess a potential as an alternative soil amendment material and as an alternative silicon source.