Marcha de absorção de nutrientes e uso de propiconazol associado a doses de nitrogênio no feijoeiro comum

Abstract

To define an efficient fertilization program it is important to understand the nutritional demand of modern common bean cultivars (Phaseolus vulgaris L.). The nutrient must be available for absorption at the time of greatest demand for the crop, so that fertilization is efficient, obtaining greater gain, economy and producer and lower nutrient losses in the environment. The present study was divided into two articles. The first article aimed to create an absorption curve and quantify a nutrient export by four bean cultivars (BRS FC 104, TAA Gol, TAA Dama and IPR Tuíiú). The experimental design was in randomized blocks with four replications. Was evaluate the nutrient accumulation and export by plant collect at V4 (4, 6 and 8 trifolium) and reproductive (R5, R7, R8 and R9) stages. Were determined total dry mass and nutrients accumulation in each phenological stage, an increase yield and export of nutrients. At stage V4, with six and eight trifoliums, TAA Gol cultivar exhibits faster initial development and greater increase in dry mass and nutrients. In R7, one cultivar that accumulated more dry mass and nutrients was a TAA Dama, and from R8 no differences were found between cultivars. Nutrient exportation was similar between cultivars. In the second article has been investigated the use of propiconazole as a growth reducer in common bean, associated with different doses of N in coverage. The experiment was carried in two crops, randomized blocks, with three replications in the split plot scheme. In the plots were applied 4 doses of N (0, 45, 90 and 135 kg ha-1) and subplots, or propiconazole in stage V4, with four trifolium. Were evaluate height, first pod insertion, number of pods, number of grains, number of nodes, number of branches per plant and grain yield. The use of propiconazole does not reduce plant height, pod insertion, pod number and grain. The cultivar TAA Gol was more productive in two crops. There was an increase in grain yield with increased doses of N in coverage.