Phosphorus Use Efficiency By Bean Cultivars Grown in Savannah Soil.

Deficiency of phosphorus is the most common plant nutritional stress in many regions of the world, especially in the developing countries. The soils of Brazilian Savannah (Cerrado) are naturally poor in P, requiring application of large amounts of phosphate fertilizer. With the increasing global demand for food and shortage of phosphate rocks, it has becomes need the intensification of study on increase nutrient use efficiency by crops for reducing fertilizer inputs. Common bean (Phaseolus vulgaris L.) is considered a major source of protein and minerals in the diets of many developing countries. However, the yield of this crop is often limited due to deficiency of phosphorus in soils. This study aimed to evaluate the P use efficiency (PUE) by common bean cultivars grown in Brazilian Savannah soil. Nineteen common bean cultivars recommended for savannah region were compared in two P levels: 20 mg kg^-1 (low level) and 200 mg kg^-1 (high level). The experiment was conducted in greenhouse in a completely randomized factorial design 2 X 19 with four replications. Seedlings were harvested 40 days after seeding and, the shoot dry weight, shoot P-concentration, P-uptake and PUE were determined. Differences among the cultivars were compared using the T test at α = 0.05, and screening methods were used to evaluate common bean cultivars for PUE. Shoot P-concentration, P-uptake and were significantly different among the cultivars. Significant differences were found among the common bean cultivars for PUE. Cultivars BRS Pontal, BRS Requinte, BRS Campeiro, BRS Marfim, BRS Esplendor and BRS Agreste were classified as efficient and responsive, while the cultivars BRS Executivo, Jalo Precoce and Roxo 90 were classified as efficient and not responsive. The discovering of new cultivars with higher PUE, coupled with best management practices will contribute to sustainable agricultural systems and encourages expanding agriculture on low-P soils.