Growth, development and yield of pigeon pea (Cajanus cajan (L.) Millsp.) in the lowland tropics:2. Effect of reduced assimilatory capacity

Abstract

SUMMARYIn two field trials in 1980, 33, 67 or 100% of the leaves on pigeon pea (cv. Cita-1) plants were removed either at the vegetative stage, the onset of flowering, or at the rapid pod-filling stage, in order to evaluate the effect of reduced assimilatory capacity on the growth and yield characteristics of the crop.Reduction in the assimilatory capacity of the plant led to significant reduction in the vegetative growth, dry-matter accumulation and seed yield of the defoliated plants compared with the undefoliated control such that 33, 67 or 100% defoliation led to 15–55, 40–60 and 75–80% reduction in seed yield respectively, at both trials. Also, defoliation was more damaging to crop performance if carried out from the onset of flowering than at the vegetative stage. Thus, the seed yields of plants defoliated at the onset of flowering and the rapid pod-filling stage were 30–80 and 40–45 % lower than the yield from plants defoliated at the vegetative stage in both trials.