Yield and physiological quality of common bean grains as a function of boron application in the soil

We carried out a field experiment to evaluate the effects of soil application of sources and doses of boron (B) on production yield and quality of grains of Phaseolus vulgaris (BRS Estilo) grown in an irrigated system. The factorial design was 4x5, being four sources of boron (boric acid, borax, borogran, and FTE BR12) and five doses (0, 1, 2, 3, and 4 kg ha-1) (three replications). We evaluated relative chlorophyll index (RCI), leaf B content, yield, seed viability, and economic value. The data were subjected to analysis of variance, and when significant, evaluated by Tukey test (qualitative) and regression (quantitative). Boron sources affected the RCI 28 days after emergence (DAE). The results for boric acid, borogran, and FTE BR12 were significantly higher (3%, p-value<0.05) than the results for borax. At 46 DAE, boric acid resulted in a RCI 5% higher than the other sources. Borax and boric acid promoted high leaf B contents (126.11 and 105.63 mg dm-3, respectively). The maximum yield (2,224.03 kg ha-1) was obtained by using 2.21 kg ha-1 of B, regardless of the source. Seed viability showed a linear behavior by using borax and boric acid and a quadratic behavior by using borogran and FTE BR12. The dose that resulted in the highest differential profit return (US$ 398.00) was 3.00 kg ha-1. Based on the productive, physiological, and economic results, the dose of 3.00 kg ha-1 provides the highest profit margin for common bean producers