Late Blight of Potato (Phytophthora infestans) Biology, Economic Importance and its Management Approaches

Abstract

Late blight is the most destructive of all potato disease and responsible for the Irish Famine in the middle of the 19^th century. It affects both potato foliage in the field and tuber in the storage which can absolutely destroy a crop, producing a 100% crop loss. The pathogen (Phyhtophthora infestans) have different mechanisms of survival and two infection phases in its life cycle. It requires two mating types, A1 and A2 to produce a sexual spore known as oospore. The spores are carried by wind and rain splash to healthy plants. A number of management techniques of late blight have been developed and used though out the world. Effective control of this disease requires implementing an integrated disease management approach. The most important measures are cultural control, use of resistant varieties, chemical control and integrated disease management. Integration of late blight management has often been thought as one of the better disease management options in tropical regions where fungal inocula are abundant in most months of the year.

Keywords: Irish Famine; Pathogen; Integrated Disease Management (IDM); Life cycle