Physiological Responses of Stress Tolerant Rice Varieties across Different Cropping Systems under Rainfed Stress

Abstract

Rice, sustaining half of the world's population, is traditionally cultivated through transplanting, particularly in Asia. However, challenges like excessive water use, labour demands, and environmental stresses like drought prompt the search for alternatives. Our study evaluates the impact of various crop establishment methods (CEs) – conventional puddled transplanting, direct drill seeding on flatbeds (DSR), and direct seeding on raised beds (FIRB) – on five stress-tolerant rice varieties (V): DRR 42, DRR 44, Sukha Dhan 5, Sukha Dhan 6, and Sarjoo 52. The key physiological parameters like Relative Water Content, Membrane Stability Index, and Chlorophyll content were analysed across different CE and V combinations. Notably, FIRB consistently surpasses other methods, suggesting its potential in bolstering stress tolerance and yield. Among the five varieties, Sukha Dhan 5 (V3) displays the highest RWC, Sarjoo 52 (V5) in MSI, and DRR 44 (V2) demonstrates superior chlorophyll content. These varieties underscore their pivotal role in maintaining plant water status, facilitating robust photosynthesis, and enhancing stress resilience, thereby ensuring stable yields. Our findings underscore FIRB's promise in curbing water waste and mitigating drawbacks associated with conventional transplanting practices.