Grain yield of Phaseolus vulgaris in a function of application of boron in soil

Abstract

The objective of this study is to evaluate the effects of sources and doses of boron on the physiological quality and production yield of Phaseolus vulgaris grown using a central pivot irrigated system on a tropical climate region. The experiment was a 4x5 factorial design representing four sources of boron (boric acid, borax, borogran and FTE BR 12) and five boron doses (0, 1, 2, 3 and 4 kg ha-1), with four replications. The following parameters were measured: relative chlorophyll index, transpiration, CO2 internal concentration, stomatal conductance, net photosynthesis, B content, grain yield and economic analysis. The relative chlorophyll index (RCI) of plants showed no significant effects at both 28 and 46 days after emergence (DAE). The extraction order of boron was boric acid > borax > FTE BR12 > Borogran. The application of boron did not affect the physiological quality (stomatal conductance, transpiration and internal concentration of CO2). However, the net photosynthetic rate was lower when boric acid was applied in relation to other sources. The maximum production (4,446 kg ha-1) was obtained using 1.35 kg ha-1 of B with the use of boric acid. However, according to an evaluation of economic viability, it is observed that there are economic differences among sources of boron and evaluated doses. The application of 4 kg ha-1 of borax provides the highest economic return.