Changes in seed vigour of faba bean (Vicia faba L.) cultivars during development and maturity

Abstract

A split plot experiment (using RCB design) with 3 replications was conducted in 2007, in order to determine the best developmental stage of three faba bean (Vicia faba L.) cultivars (Aquodolce, Barakat and Zohreh) at which maximum seed vigour is attained under different irrigation regimes (I1, I2 and I3: irrigation after 70, 100 and 130 mm evaporation from class A pan, respectively). Seeds were harvested at five day intervals in eight stages. Seed quality of all cultivars under different irrigation regimes was enhanced with improving seed development on mother plants. Maximum seed vigour as measured by germination rate and electrical conductivity of seed leachates, was obtained at about mass maturity or slightly after this stage. At earlier harvests, because of immaturity, and at later harvests, due to ageing, seed vigour was low. Maximum seed weight under the well-irrigation treatment was significantly higher than that under limited irrigations, but maximum percentage and rate of germination and minimum electrical conductivity were not significantly affected by water supply. Significant differences in maximum seed weight and quality among cultivars were attributed to the differences in genetic constitution. In general, it was concluded that high vigour seeds of faba bean cultivars can be produced under both well and limited irrigation conditions, providing that the seeds are harvested at about 20% moisture content.