Plant spacing in French beans. I. Yield

Four cultivars of French beans (Phaseolus vulgaris L.) were grown at a range of plant population densities and rectangularities in two seasons in south-eastern Queensland. Plant population densities two to three times those used commercially increased yields by 25-30%. This increase resulted from a greater number of pods per unit area with only a small reduction in pod size. Rectangularity in the range 1-8 had no effect on yield. These responses are discussed in terms of time courses of leaf area index development, light interception by canopies, crop growth rates and dry matter distribution between vegetative and reproductive growth after flowering.