The fungal pathogen has dark brown mycelium with simple erect conidiophores bearing chains of conidia. Large conidia are dark pear shaped and multicellular, and are detached easily by air currents. The A. solani Sorauer can survive on tomato debris or in seeds during winter period (Agrios, 1997; Rotem, 1994). The early blight *Corresponding author. E-mail: ozer.calis@gop.edu.tr. Tel: ++903562521616/2260. Fax: ++903562521488. pathogen produces several toxins to infect tomato plants. Among these toxins alternatic acid and solanapyrone induce necrotic symptoms with encircled chlorosis and these toxins enhance the pathogen infection and the development of necrotic symptoms of A. solani (Langsdorf et al., 1990).