Plant Population Effects on the Seed Yield Components of Beans1

Abstract

Knowledge of the effect of plant populations on the seed yield components of beans (Phaseolus vulgaris L.) is needed to design management systems utilizing the genetic potential of different cultivars and to aid in the development of higher seed‐yielding cultivars. The objectives of this study were to evaluate (a) the effect different plant populations (area/plant) on the seed yield components as related to seed yield/plant, and (b) the relative differences between determinate (‘Canyon’, and ‘Blue Lakes 274’) and indeterminate (‘UI‐II4’, and ‘Big Bend’) bean cultivars. Seed yield/plant and the seed yield components were measured on plant populations from 107,600 to 968,700 plants/ha (100 to 930 cm2/plant) grown in a systematic design. Data were evaluated by path coefficient analysis based on correlations calculated from logarithmically transformed data. Pods/plants increased linearly as area/plant increased (decreasing plant population) for all cultivars studied, and had the largest effect on seed yield/plant. Seeds/pod and g/seed also increased as area/plant increased for the indeterminate cultivars, but remained relatively constant for the determinate cultivars. As a result, the seed yield/area is relatively constant over a wide range of plant populations for the indeterminate cultivars, but decreases at the smaller plant populations for the determinate cultivars. It also indicates that the determinate cultivar is subject to less competitive stress than the indeterminate one at the higher plant populations. The greatest potential for seed yield increases in high plant populations is with determinate cultivars.