Abstract

This study aimed to investigate the effect of the foliar application of phosphite and phosphate on growth, phosphorus (P) status, and nutritional aspect of common bean (Phaseolus vulgaris cv. Radiante) plants grown under different soil phosphate levels. Experiment was organized in factorial scheme completely randomized using 2 soil phosphate levels (Pi-starved and Pi-sufficient plants), combined with 3 nutrient sources supplied via foliar application (KH₂PO₃, KH₂PO₄, and KCl used as control), and 2 foliar application numbers (single and two applications). In this study were measured root dry weight, shoot dry weight, and root to shoot ratio, as well as shoot P concentration, root P concentration, accumulated P in shoot, accumulated P in root, P uptake efficiency, P utilization efficiency, P translocation, and macro and micronutrients in shoot. Common bean growth under limiting phosphate availability in soil exhibited lower biomass yield and higher concentration of nutrients in shoot tissues. The results exhibit foliar-applied KH₂PO₃ causes harmful effects in phosphate-starved common bean. Either one or two foliar sprays of KH₂PO₄ were not sufficient to affect the growth and nutrition of the common bean plants, regardless of soil P status.

Key words: Phaseolus vulgaris, phosphorus, phosphate and phosphite anions, foliar application.