Cashew (Anacardium occidentale L.) is an important tropical tree crops. It belongs to the Anacardiaceae family, which includes about 60 genera and 400 species, among them mango (Mangifera indica L.) and pistachio (Pistacia vera L.) are also included. Cashew affected some diseases such as die back of cashew (Corticium salmonicolor), dumping of seedling (Pusarium sp, Pyihium sp, Phyiophtora palmivora and Cylindrocladium scoparium), grey leaf blight (pestalotia anacardii), leaf spot (Cryptosporiopsis sp.), angular leaf spot (Septoria anacardii), anthrecnoce (Colletotrichum gloeosporoides), Powdery mildew (Oidium anacardii Noack).Among them various fungal diseases, grey leaf blight is an important disease and commonly observed during monsoon season. grey blight disease first appeared in the field as minute yellow spots encircled by a grayish band on the leaflets. These spots later on coalesce into irregular necrotic patches. Gradually, the center turns grayish white and the brown band darken. In severe infection, complete blight drying and shriveling of the leaf blade occurred.