Seasonal and system wise variation in disease and insect pest incidence in plantation crops of Wayanad district

A study was undertaken in the plantation crop based cropping system plots of Wayanad district to assess disease and pest incidence during different seasons in major crops and the variations in incidence of disease and pests between various cropping systems. In coconut, grey blight was extremely high during all seasons. Eriophyid mite attack was highest during south west (SW) monsoon (80%). Arecanut palms were mainly infected by Colletotrichum leaf spot, grey blight, inflorescence blight& button shedding and leaf rot during all seasons. Spindle bug infestation was highest during north east (NE) monsoon season (46.6%). In pepper, foot rot, yellow mottle, fungal pollu and marginal thrips was noticed in all seasons. In coffee, severe incidence of Colletotrichum leaf spot was noticed during summer (65.1%). Cardamom plants were mainly affected by leaf rot, leaf blotch and shoot borer during all the three seasons. In tea, the incidence of grey blight and stem borer attack was highest during summer. Study of seasonal variation in disease/ insect pest incidence between cropping systems showed that in arecanut, spindle bug attack was relatively greater when intercropped with nutmeg and tea during summer, with banana and nutmeg during SW monsoon and with coconut during NE monsoon. Incidence of foot rot was more in pepper grown along with tea during all seasons. During the two monsoon seasons, blister blight of tea was more in tea with pepper as intercrop and sooty mould was higher in tea intercropped with arecanut.