Epiphytotics of early blight of tomatoes in Northeastern Nigeria

Abstract Epiphytotics of early blight caused by Alternaria solani were observed in tomato fields at Maiduguri (Sudan Savannah) and Mubi (Northern Guinea Savannah) in Northern Nigeria between July and September of 1994 and 1995. This is the first time the status of the disease has been evaluated in the region outside the wetter zones of Zaria-Kaduna and Southern Nigeria. Of the ten tomato cultivars used in the study of this disease, four, Raci, T1-244, T1-468 and T1-530, were tolerant to early blight, producing relatively higher yields. The disease was found to be more severe in the Northern Guinea Savannah than in the Sudan Savannah and was strongly influenced by rainfall and relative humidity. The pathogen caused leaf defoliation and fruit infection. Flowering and fruiting were impaired. Levels of fruit infection were highest on Raci, T1-244 and Dandino. The overall effects of A. solani infection in both ecological zones were reduced yield and reduced fruit quality.