Phytophthora infestans, a pathogen of class Phycomycetes attacks a number of members of family-Solanaceae, the being potato and tomato. It causes blight over leaflets, tubers and the disease is known as late blight of potato since, its destruction is seen in the later stages (under cool and moist conditions) of the plant not only destroying the whole field but the infection continues to advance inside the tubers under storage conditions. Ustilago (class-Basidiomycetes) is a parasite growing on several plants (mostly Graminae family) and causes smut disease (loose or covered smuts) by producting spores termed as teliospores, or chlamydospores, eg, Ustilago nude van tritici causes loose smut of wheat. Colletotrichum falcatum is incitant of red rot of sugarcane.