Interactions of insect pests, diseases, and Sub1 rice varieties across agro-climatic zones in Assam: insights for strengthening resilient rice cultivation

This study investigates the prevalence and interaction of insect pests and diseases across the agro-climatic zones of Assam, which are deployed with submergence-tolerant (Sub1) rice varieties. Utilizing data collected from farmers’ fields over 2 years (2020 and 2022), the research provides novel insights into how host genotype and climatic zones influence insect pests and disease prevalence under real-world conditions. The results reveal significant variability in insect and disease incidence across different agro-climatic zones and among rice varieties. The Central Brahmaputra Valley (CBV) zone exhibited a higher prevalence of insect pests such as the L. acuta , S. incertulas , and C. medinalis , while the Lower Brahmaputra Valley (LBV) zone demonstrated increased disease incidence, particularly of M. oryzae and B. oryzae . Similarly, varietal responses varied across agro-climatic zones; Bahadur-Sub1 exhibited comparatively lower insect and disease incidence, whereas Bina dhan 11 showed higher L. acuta and C. medinalis incidence across zones. Principal component analysis underscored zone-specific associations between insect pests and diseases, emphasizing the complex interactions among host plants, agro-climatic conditions, and insect-pest population buildup. Temporal variation was also observed, with differences in insect pests and disease prevalence between the 2 years, highlighting the impact of macro and micro-climatic factors. These findings suggest continuous monitoring and development of adaptive, zone-specific insect and disease management strategies that can minimize insect-pest adaptation and enhance the resilience and productivity of rainfed rice ecosystems in Assam.