The response of field beans (Vicia faba L.) to irrigation and sowing date:1. Yield and yield components

Abstract

summaryThe response of 4 crops of autumn- and spring-sown field beans cv. Maris Bead to irrigation applied during the vegetative, flowering and pod-filling phases was examined during 1981–2 and 1982–3. The crops, grown on a Templeton silt-loam, were irrigated weekly in amounts equal to the difference between the estimated evapotranspiration and rainfall of the previous week using trickle irrigation.Seed yield of fully irrigated autumn- and spring-sown crops (averaged over the two seasons), was 5·2 and 3·3 t/ha respectively, about 45% greater than the yield of unirrigated crops. The increase in yield due to irrigation was mainly associated with an increase in total dry matter (TDM) production as harvest index varied little within each sowing. The yield response to each mm of applied irrigation water ranged from 0 to 9 kg/ha and did not appear to be related in any way to the developmental phase of the crop when irrigation was applied.Seed yield within each sowing was closely correlated with the number of beans per unit area and the number of pods per plant. Autumn sowings yielded about 55% more than spring sowings mainly due to a higher harvest index which was associated with a much heavier mean weight per bean.