Common vetch Vicia sativa L. response to gibberellic acid application (GA3), supplementary irrigation and its water stress critical stages

Physiological responses to gibberellic acid, irrigation and water stress were investigated in common vetch. It was observed that supplementary irrigation (75 % of soil available capacity) resulted in significant reductions in plant height (20.5%), plant length (15.3%), number of node on main stem (11%), leaflet/leaf (8.5%), weight of 1000 seeds (28%), biomass (65.9%) and seed yield (43.6%), as compared to 25% level of watering. Regression analysis manifested that Vetch yield linearly responded to irrigation levels. Vetch plants treated with 200mg/L GA3 resulted in significant increases in biomass (37.2%), pod number per plant (43%) and seed yield (32%), as compared to untreated. Moreover, 100 mg/l GA3 highly exceeded in node number on main stem (8.2%), biomass (7.1%) and seed yield (11.6%). Regression analysis revealed that vetch yield was linearly related to irrigation levels. Vetch plant treated with 200 mg/l GA3 grown under 25% level gave the highest plant height (49.33 cm), first fruiting node (12.33), biomass yield (672.67 g.m-2),and seed yield (142.33 g.m-2). However the lowest values were confined to untreated with 75% level watering in seed yield (79.33g.m-2). It was also found that withholding complementary watering during the pod swelling and seed fillings resulted in profound reductions in weight of 1000 seeds (5.2%), biomass yield.m-2 (26.8 g) and seed yield per m-2 (23%). However, first fruiting node (33.3%) and pod number per plant (25.7%) were significantly increased, as compared to continuous watering.