Yield and Yield Components Affected by Leaf Water Status in Field-grown Common Bean Genotypes under Two Contrasting Irrigation Regimes

ABSTRACT: physiological response of common bean yield to leaf water status plays a key role to understanding the yield loss in limiting conditions. to investigate the responses of common bean genotypes (akhtar, mcd-4011, wa-4531-17, cos16, d81083, and-1007, wa-4502-1 and ks21486) and moisture regimes (i1 and i2: irrigation after 55 to 60 and 100 to 110 mm evaporation from class a pan, respectively), a split-plot experiment using randomized complete block (rcb) design with four replications was conducted. significant changes in leaf relative water content (rwc) and water potential (?w) of genotypes induced by water deficit were 52.12% (ks21486) to 49.86% (akhtar), and -1.58 mpa (ks21486) to -2.46 mpa (d81083). during the growing season, rwc and ?w values of i2 were significantly lower than those of i1. the interrelationship of ?w and rwc revealed that wa-4531-17 and d81083 in non-stressed, and wa-4502-1, and-1007 and d81083 in water deficit stressed conditions had the lowest rwc reductions per unit decrease of leaf ?w. increased grain yields of wa-4502-1, wa-4531-17 and and-1007 were due to increased 1000 grains weight. the results of this experiment showed that the genotypes with suitable water content in their leaf tissues, wa-4502-1, wa-4531-17 and and-1007 produce relatively high grain yield under water limited conditions. d81083 produced low grain yield because of its minimum levels of grains and pods per plant (in spite of suitable leaf moisture content).