On the ordered development of plants 3. Branching by the grain legume Cyamopsis tetragonoloba(Guar)

Abstract

Two selections of guar (Cyamopsis tetragonoloba (L.) Taub.) with contrasting branching patterns were grown at three plant densities at two times of the year. The numbers of growing vegetative meristems (branches and main stems) per unit ground area at the start of reproductive growth were linearly related to the amount of the incident light energy intercepted by the different crops of each selection. The data were consistent with the hypothesis that each vegetative meristem required a minimum assimilate flux to continue growth and, further, that meristems on the highly branching selection required approximately one-quarter of the assimilate flux required by vegetative meristems on the relatively non-branching selection. The effect of increasing plant density in reducing branching by individual plants of a particular selection was also consistent with this hypothesis.The hypothesis accounted quantitatively for the observed three-dimensional distribution of vegetative meristems through the volumes of crop canopies at each of the three plant densities. The implications of this analysis to the field performance of crops comprising plants with different branching patterns are discussed. © 1984 Annals of Botany Company.