Impact of Rice Cultivation Methods on Insect Pest Incidence and Their Management

Abstract

Under the influence of fluctuating global climate scenario and limited resources of water availability, different methods of rice cultivation like System of rice intensification (SRI), Direct seeded rice (DSR), Alternate wetting and drying (AWD) and Aerobic rice have become popular as alternatives to conventional transplanting method. Due to these shifting cultivation situations, insect pest profiles have also undergone changes with associated influence on beneficial insects and other natural enemies. Multi-location studies carried out under All India Coordinated Rice Improvement Project (AICRIP) have revealed significantly less incidence of major pests like stem borers, planthoppers in SRI compared to normal rice transplanting method. Overall, the SRI method leads to more robust plant health with enhanced capacity to resist pest attacks. In case of DSR, AICRIP studies have consistently revealed higher incidence of all the insect pests in the normal transplanted method compared to DSR. However, few reports have indicated association of insect pest outbreaks with higher seed rate and plant densities. Limited studies have shown that AWD also has the potential to minimize the incidence of insect pests and diseases compared to irrigated rice. However, soil borne pests, particularly root-knot nematode can be more damaging under aerobic conditions. Field cum laboratory studies carried out at ICAR IIRR on impact of cultivation systems on the rich insect biodiversity in rice have revealed association of higher total abundance and greater richness of beneficial insect species with SRI management.