Variability in yield of four grain legume species in a subhumid temperate environment. II. Yield components

The effects of plant population (one-tenth of the optimum to four times the optimum populations in 1998/99 and 10-400 plants/m(2) in 1999/2000) and sowing depth (2, 5 and 10 cm) on yield and yield components of four grain-legumes (Cicer arietinum, Lens culinaris, Lupinus angustifolius and Pisum sativum) were studied. Seed yields were strongly positively correlated with the number of pods and seeds/m(2) in both years in all species. The mean seed weight and number of branches/plant were inversely related to plant population. There was a nearly six-fold reduction in the number of branches/plant as plant population increased, which was due to restricted branching, and not to branch senescence. Generally, the variation in yield components was species dependent. However, for all species the number of pods/m(2) and seeds/m(2) could be used as primary criteria for selection in a breeding programme.