A novel perspective on seed yield of broad bean (Vicia faba L.): differences resulting from pod characteristics

Broad bean (Vicia faba L.) is an important crop worldwide. An increase in seed yield would increase both the grain reserve and the profit for farmers. Previous studies on increasing broad bean seed yield have focused mainly on increases at the whole population level. Few studies have focused on the differences in plant type within populations. In this study, we classified broad bean plants into four categories based on pod type, and then evaluated the ratio of each category in field-grown broad bean populations. We analysed the seed and pod characteristics of each category, and their contributions to total seed yield. The number of seeds per pod, and the number of pods or seeds per plant differed among the four plant categories, but the seed weight was relatively uniform. There were significant differences in seed yield per plant among the four plant categories. We calculated the effects of increasing the proportion of each plant category by 10% or to 100% on seed yield, and found that seed yield could be improved by increasing the ratio of plants with the highest seed production rate. This study provides a novel perspective on estimating the seed yield of broad bean.