METHODS OF APPLICATION AND DOSES OF PHOSPHORUS ON COMMON BEAN GROWTH

Abstract

Increasing doses of phosphorus (0, 50, 100, 200, 400 and 800 kg ha-1) as KH2PO4 were applied in a Ultisol to study the effect of levels and manners of fertilizer application, on common bean growth (Phaseolus vulgaris L.), cv. Mexican, in an experiment at green house conditions. Brisbane city is located at 27 25 S latitude, 152 54 E longitude and 154 m over the sea. The air temperatures from october to november of 1990 varied from 40º C maximum and 21º C minimum. The phosphorus was applied in covering and incorporate before planting; in strip after the planting and in furrow at the planting. The highest values of plant height and production of dry matter were obtained with application of the mean doses of 535 and 380 kg of phosphorus ha-1, respectively. The best common bean plant growth was observed when the phosphorus was applied in covering and incorporated to the soil but the largest production of dry matter happened when the phosphorus was applied in strip. The maximum concentrations of nitrogen and phosphorus in the leaf tissue reached 20.8 and 2.96 g kg-1, respectively. The concentration of magnesium in the leaf varied between 2 and 4 g kg-1 and the maximum concentration of calcium in the leaf was 30 g kg-1. According to the analyses of plant parameters used to evaluate the development of the common bean, the best results were obtained when the phosphorus fertilizer was applied in strip; the largest plant height didn’t correspond to the largest production of dry matter.

KEY-WORDS: Phaseolus vulgaris; fertilizer management; growing doses; mineral nutrition.