An analysis of the growth of mung beans at a range of plant densities in tropical Australia. II. Seed production

Abstract

An analysis of seed production by crops of Vigna radiata cvv. Berken and CES-ID-21 and V. mungo cv. Regur, grown at a range of plant densities, indicated that the proportion of carbon assimilated during pod-filling and partitioned to the seed varied in such a way that seed yield at maturity was relatively unaffected by plant density. Seed yield of Regur was much higher than that of either Berken or CES-ID-21, and this could be attributed primarily to the longer duration of pod-filling in Regur rather than to any differences in potential pod growth rates. The data support the hypothesis that during the period of pod initiation, each viable pod requires a critical rate of supply of assimilate, and suggest that this critical rate of supply is less for V. mungo than for V. uadiata. Whilst pod number, and hence seed yield, was determined by the rate of assimilate supply during the period of pod initiation, not all the dry matter accumulated during pod-filling was partitioned to the pods. Hence seed yield in these mung bean cultivars does not appear to be determined solely by assimilate supply during pod-filling.