XVI International Botanical Congess

Pigeonpea (Cajanus cajan L) Millsp is an important leguminous crop for food, fodder, fuel and enrichment of nutrient deficient soil. Although pigeonpea thrive best in Manipur hills with its diversity in host varieties and habits, yet the crop hosts the diversity of fungal pathogens and diseases: foliar rusts, powdery mildew, Cercospora leafspots, Alteraria, Phytophythora leaf blight and Fusarium wilt were found associated with the pigeonpea causing heavy yield loss to the crop. An aerobiological survey of the incident of these disease showed three peaks in spore accumulation. Disease calendar denoting periodicity of these diseases has been prepared for different host varieties based on data of three consecutive years periodic surveillance of the crop. Periodicity of these disease occurrence was almost the same for different varieties. However, the degree of disease incidence and severity on different varieties for different disease were significantly different. A forecasting and management of these diseases can be made on the basis of the results and discussed in the full length of the paper.