Yield determinants of Guar ( Cyamopsis tetragonoloba): 1. Grain yield and pod number

Abstract

Yields of crops of two selections of guar ( Cyamopsis tetragonoloba) with contrasting branching patterns, each selection grown at three plant densities both in rows and as isometric stands, were primarily determined by the number of pods set. Whereas the yields of both selections were similar to isometric stands when grown at high plant densities (ca. 4.3 t ha −1), when grown as row-crops the yield of the less-branching selection was 25% higher and that of the more-branching selection 25% lower. With all crops the number of viable pods present at any harvest was linearly related to the rate of new, above-ground dry-matter production by the crop at the time of harvest. The data accord with the simple thesis that the rate of supply of carbon assimilate to the generative organs is the main determinant of their number.