Effects of Different Watering Regimes on Growth, Yield and Photosynthetic Ability of Some Mungbean [<i>Vigna radiata</i> (L)] Cultivars

Global environmental challenges, particularly those driven by climate change, have disrupted precipitation patterns, causing irregular rainfall distribution and water stress in agricultural systems. This study investigates the effects of varying watering regimes on the growth, yield, and photosynthetic ability of two mungbean (Vigna radiata) cultivars, IC-39409 and SWETA. Conducted using a randomized complete block design (RCBD) in a split-plot layout, the experiment included five watering intervals: control (2-day interval), 4-day, 6-day, 8-day, and 10-day intervals. Growth parameters such as plant height, leaf area index, were measured alongside yield and photosynthetic efficiency. Data were analyzed using a two-way analysis of variance. The results revealed that both cultivars exhibited consistent responses across all watering regimes. Maximum growth and yield were observed at the 4- day interval (WR2), with significant improvements in plant height. Both cultivars demonstrated tolerance to water stress up to a threshold of 4 to 6 days without significant reductions in yield or growth. Photosynthetic ability remained unaffected even under drought conditions up to a 10-day interval, highlighting the resilience of mungbean to moderate water stress. However, extended watering intervals beyond six days led to a decline in yield stability and overall plant performance. This research addresses critical gaps in understanding how intermediate watering intervals affect mungbean growth parameters, including and photosynthesis, under water-limited conditions. Unlike prior studies that focused on extreme drought or well-watered regimes, this work uniquely explores the balance between water stress tolerance and optimal resource utilization. The novelty lies in its holistic approach to evaluating drought thresholds for mungbean cultivars while providing practical insights into irrigation strategies for sustainable productivity amidst changing climatic conditions.