One to two foliar applications of NPKS solutions enhanced yields from 10–40% when applied to pot grown bean plants (Phaseolus vulgaris, var. Bulgarian) during the seed filling period. Further spray applications had progressively more negative effects on yields. Addition of calcium ions or cytokinin to the spray treatments did not give further yield increases. Addition of an organo‐silicone surfactant (L77) to the spray solution gave higher yield increases than those obtained by adding a carbohydrate based surfactant (Tween 80). Percent N P and K contents of the bean seeds were inversely related to yields suggesting that the rate of supply of these minerals to the seeds was not limiting production; the results support the idea that leaf integrity was one of the main factors affected by late season N P K S sprays, and that this in turn affected yields.