Impact of soil amendments and weather factors on bacterial wilt and yield of two tomato cultivars in Abeokuta, Nigeria

Abstract

Tomato bacterial wilt, caused by Ralstonia solanacearum, leads to tomato yield losses of up to 80% in south-western Nigeria. Soil amendments and weather conditions are important in the management of the disease. Field experiments were conducted at the Research Farm of the Federal University of Agriculture, Abeokuta, Nigeria in the late and early rainy seasons of 2006 and 2007, respectively, to evaluate the effects of soil amended with three bactericidal plant materials and prevailing weather conditions on severity of tomato bacterial wilt and yield of two tomato cultivars. The experiment was designed in a split-plot with cultivars as main plot and composts as subplots. Soil amendment with bactericidal plant material reduced mean soil population of Ralstonia solanacearum by 4.78 × 10⁷ cfu g^-1 soil, mean wilt incidence by 31.35%, percent severity index by 22.90, and increased tomato yield by 50%. Relationships between disease severity index (Y) and cumulative number of rainy days (X) in 2006 and 2007 were described, respectively, by linear models Y = 4.093X – 78.2 and Y = 2.593X – 10.81. Growing tomato on soil amended with bactericidal plant materials under fewer rainy days reduced bacterial wilt and increased yield of tomato.