Interactions between and within inflorescences in relation to the storage capacity of field beans (Vicia faba)

Abstract

SummaryTwo field experiments and one pot experiment were carried out to test the hypothesis that competition and dominance relations between and within inflorescences control seed yield. The experiments compared untreated field bean (Vicia faba L.) plants with others in which the numbers of inflorescences and flowers had been surgically reduced to 18 defined positions at lower or at upper nodes. Growth conditions were varied by sowing date and plant density. Seed yields, yield components and 14C-labelled assimilate distribution were determined.Most untreated plants set no more than 18 pods while treated ones set 4–7 pods fewer. As variation in seed set per pod was small, the resulting number of seeds remained about 30% less in treated compared with untreated plants. In plants with pods set only at upper nodes, 14C-assimilate distribution shifted in favour of leaf and root production, presumably supporting seed production later on. Concerning seed yield per plant, full compensation was reached as mean weights per seed increased up to 40%. In interactions with growth conditions, small overcompensation effects on seed yield per plant were indicated. Results are discussed in relation to storage capacity and yield stability.