Adubação borratada residual na cultura do girassol

Abstract

The objective of this work was to analyze the effects of residual borate adduction in the sunflower crop. The experimental design used was randomized blocks, arranged in a 5 x 6 factorial scheme, with 4 replications. The factors refer to the phenological stages of the soybean crop (predecessor) (V0, V3, V6, V9 and R1) and boron doses (0, 1, 2, 3, 4 and 5 kg ha-1), in predecessor crop (soybean) respectively. The application of boron was carried out in the 2017/2018 harvest in the soybean crop, and the sunflower sowing was carried out on the sowing line of the soybean crop. Leaf boron concentration, relative chlorophyll index, plant height, stem diameter, head diameter, number of achenes per head, mass of 1000 achenes and productivity were evaluated. The application of boron in the phenological stages in the soybean crop positively influenced the parameters evaluated in the sunflower crop. The use of doses between 1.82 and 2.20 kg ha-1 of B influenced the stem diameter and number of achenes per head. The productivity of the sunflower crop submitted to boronated residual fertilization, showed positive results in function of the times and doses of boron application in the soybean crop.