Produtividade da soja em condições de sequeiro e irrigação suplementar

Abstract

The region of the grande Dourados presents records of seasonal water deficits in the summer that compromise the soybean yield, with this the irrigation becomes an alternative to enrure the hydric demand of the crop. Therefore, the objective of this work was to evaluate the effect of supplementary irrigation on the agronomic performance of four soybean varieties. The experiment was carried out in the summer crop 2016/2017 in the experimental area of Irrigation, Faculty of Agrarian Sciences, Federal University of Grande Dourados. The experimental design was a randomized complete block design in a 4x2 two - tailed scheme with five replications, totaling 40 plots. The four tested varieties (BRS 7410 IPRÓ, BMX RR Power, MSOY 6410 and BRS 1003 IPRÓ) refer to factor one (cultivars), and the growing condition (irrigated and dry) corresponds to factor two. Irrigation management was carried out based on the climatic water balance. During the harvest due to the precipitation irregularity, seven irrigation events were required, totaling an applied liquid blade of 106.04 mm. In the experiment the evaluated parameters were: plant height, height of insertion of the first pod; Number of pods per plant; Stem diameter; Mass of 100 grains and productivity. There was no statistically significant difference between the varieties for the productivity variable. It was noted that the MSOY 6410 variety was numerically more productive than the others, with a mean productivity of 3009.52 kg ha-1 . In irrigated growing, the highest averages of the evaluated parameters were observed, where irrigation provided an increment of at least 28% in productivity. The varieties BRS 1074, MSOY 6410 and BRS 1003 were the most productive under growing with supplementary irrigation, standing out the BRS 1074 variety which produced 4021.14 kg ha-1 .