Responses of faba bean (Vicia faba L. cv Maris Bead) to different levels of plant available water. II. Yield, water use and water use efficiency

Seed yield and biomass of faba bean were highly dependent on the amount of water availability and its use efficiency. One glasshouse experiment was carried out to examine the water use, water use efficiency (WUE) and seed yield of faba bean cv Maris Bead under different levels of plant available water (PAW), i.e. 20, 40, 60, 80 and 100% (control). The higher values of seed yield was obtained from 100% PAW i.e. 40% to 76% higher than other treatments. Reduction in seed yield was mainly due to reduction in pod and seed number particularly at 20% and 40% PAW. Both of these yield components were strongly correlated with seed yield (r2 = 0.92 and 0.94). Generally, seed yield increased as total water use increased, but WUE tended to increase as PAW decreased i.e. ranged from 0.8 to 1.5 g/plant/kg water use. The lowest PAW (20%) had significantly high WUE than higher PAW (100%) by approximately 46%.