EVALUATION OF THE GROWTH, PHYSIOLOGICAL AND YIELD PERFORMANCE OF COMMON BEAN (Phaseolus vulgaris L.) VARIETIES UNDER SOIL MOISTURE STRESS CONDTITIONS

Abstract

Common bean is one of the most important food crops, with significant economic importance and it is suitable for food security due to its short growing cycle and adaptability to different cropping systems. However, its average yield reported at the national levels remains far below the potential due to various biotic and abiotic constraints among which is moisture stress. The study was conducted to evaluate the effects of moisture stress on growth, physiological and yield and yield components of common bean varieties. A pot experiment was conducted under lath house from June to September 2020, at Hawassa University College of agriculture. Seven common bean varieties viz. Gofta, Fedis, Awash-2, Tinike, Awash-1, Dursitu and Nasir were grown under three irrigation intervals/moisture level viz. watered every day (waterlogging stress), watered every four days (control) and watered every eight days (moisture deficit), in factorial combination using Completely Randomized Design with three replications. The main and interaction effects were significant on Days to flowering, physiological maturity, plant height, leaf number, Shoot fresh weight, Shoot dry weight, root length, Transpiration rate, photosynthesis rate, stomata conductance, water use efficiency, stomata number, stomata width and length, chlorophyll concentration, Proline content, Length of pod, pods plant-1 , seeds pod-1 and yield gram-1 plant-1 . However, branch number and Internode length, leaf relative water content, hundred seed weight, total biomass (biological yield), straw yield and harvest index were significantly affected by main effects of moisture levels and varieties but chlorophyll fluorescence was affected by only moisture levels. Moisture stress significantly reduced growth, stomata conductance, photosynthesis, yield and yield components. Varieties performed differently in response to moisture stress. The highest hundred seed weight, biological yield, and straw yield were recorded for Awash-1 and Tinike varieties, respectively in control moisture stress. The highest yield was recorded from the variety Awash-1 and Gofta irrigated every 4 days of interval ( control); whereas the lowest yield was recorded from Fedis variety treated with daily irrigation ( water logging). Also Awash - 2 varieties is relatively better compared to the Tinike, Fedis, Dursitu and Nasir on yield and yield parameters at all moisture levels. Varieties Gofta, Awash-2 and Awash-1 appeared to be moisture stress-tolerant duo to maximum proline accumulation mechanism, high water use efficiency, low transpiration rate and better photosynthesis and yield performance by using different mechanisms.