A fie ld study was undertaken to evaluate the effect o f potassium fertilizer, when applied in different ratios, as a basal or top dressing on vegetative growth, immature pod and seed yield of French bean as well as seed quality for planting purpose determined by germination before and after controlled deterioration. The ratios o f fertilizer application at a given rate o f 100:0, 50: or 0:100, were added at planting (basal) or at flowering (R1 stage – top dressing). Establishment o f French bean was not affected by potassium. In contrast, vegetative growth and most yield components increased significantly with up to 100 kg K 20 per ha. Application o f a given rate only at planting (100:0) enhanced vegetative growth compared with a split rate. Application at flowering alone (0:100) reduced all measured parameters, confirming the requirement o f potassium at planting. Yields o f immature pods harvested for vegetable purposes were not significantly increased by the two applications in the ratio o f 50:50 (basal: top dressing). Seed quality determined by germination before and after controlled deterioration was also affected and split applications o f 100 kg K 20 in the ratio o f 50:50 increased germinability.