Pathological studies on tomato early blight [electronic resource].

Includes reference.

Tomato (Lycopersicon esculentum Mill.) is one of the most important and economic vegetable crops in Egypt. It is Subjected to infect by numerous fungi that causing considerable losses in yield and quality. Early blight disease caused by Alternaria solani was wide spread in EI-Sharkia governorate during 2004-2005 and 2005-2006 growing seasons. The highest percentage of disease incidence was recorded in EI-Ebrahimia district while the lowest one was recorded in Abo- Hammad district during two growing seasons. The causal organism was isolated from infected leaf and fruit samples (exhibited typical symptoms of early blight) collected from different localities mentioned before, and identified as A. solani. Growth of A. solani on leaves and fruits of tomato agar media, then exposed to Ultra-Violet irradiation (UV) was the best method to obtain A. solani spores. All tested isolates of A. solani were found to be pathogenic at different degrees against tomato plants Gs cv. Hynez tomato cv. was the most resistant tested cvs., while, Gs cv. was the most susceptible one. On tbe other hand, the other tested cultivars were moderately susceptible to be infect with A. solani. Old tomato leaves were more susceptible to be infect by A. solani than young one. Also, direct seed cultivation method enhanced tomato plants to be infect with A. solani than the transplanting method.

Summary in Arabic.

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