Chemical Control of Tomato Early Blight Disease

Alternaria solani (Ellis and Martin) Jones and Grout, the causal of tomato early blight, attacks all tomato hybrids and varieties, either in open field or in greenhouse, causing a serious damage that led to decrease in tomato yield. The fungus A. solani was isolated from tomato leaves and fruits, showing typical symptoms of early blight, collected from different locations distributed in six Egyptian Governorates. Pathological studies cleared that A. solani isolate taken from Menufiya was the most aggressive one; meanwhile, Ismailiya isolate was the lowest one in this concern. Disease control experiments revealed that all the tested fungicides inhibited, to different degrees, the in vitro growth of A. solani and decreased early blight severity under greenhouse conditions. The contact fungicides were more effective than the systematic ones, in controlling tomato early blight. Moreover, mancozeb 64% + metalaxyl 4% and copper hydroxide were the most effective ones, followed by systematic fungicides shirlan and dolphin Alfa.