PRODUCTION OF COMMON BEAN UNDER SATURATED SOIL CULTURE

Saturated soil culture (SSC), where crops are grown in soil continuous ly irrigated to maintain a high moisture content, has resulted in larg e increases in soybean seed yield. Common bean (Phaseolus vulgaris L.) is considered sensitive to flooding and has a shorter growth cycle th an soybean. Thus, it was anticipated that an evaluation of response of common bean to SSC might provide an instructive contrast. Four field trials were conducted at Palmira, Colombia to evaluate the response of different bean lines to SSC which resulted in up to 20% yield increas e. However, effectiveness of SSC varied with trial and bean line. In a comparison of ten lines previously characterized for adaptation to wa ter deficit, nine lines suggested a strong negative association betwee n relative yields under SSC and yield under water deficit (r = -0.84, P < 0.01) and relative yield under SSC and root length density under w ater deficit (r = -0.79, P < 0.01). The tenth showed high yields under both SSC and water deficit. Physiological maturity was delayed by SSC , and canopy dry weight increased while seed yield was improved. Effec ts on harvest index were variable with trial and line. Mean leaf condu ctance was higher and leaf temperature lower in SSC, suggesting that S SC improves crop water status. Although positive effects on seed yield were detected, response to SSC was less favorable than reported for s oybean.