Efeito do extrato de alga (Ascophyllum nodosum) em diferentes densidades de soja (Glycine max) no Oeste de Santa Catarina

Abstract

In Brazil, soy cultivation is the agricultural activity that has grown the most in recent years. Crop productivity has been increasing in recent harvests, but new technologies are needed to further increase the productive potential, such as the use of biostimulants based on algae extracts. Therefore, this research intended to verify the influence of brown algae extract (Ascophyllum nodosum) in foliar applications on the performance of soybean (Glycine max) at different population densities. The experiment was carried out in a commercial soybean area, in the municipality of Chapecó, in the 2019/2020 harvest. For the assay, the soybean cultivar NA5909RG® was used, in a randomized block design, with four replications. The treatments consisted of a 2x4 factorial, with the first factor being the foliar application or not of the algae-based biostimulant (Carboplex®) at a dose of 0.5 ml/ha; the second factor was composed of soy plant densities (160,000, 190,000, 220,000 and 250,000 plants/ha). The biostimulant applications occurred in three distinct phenological stages (V4, R1 and R5). The evaluations used were: plant height; number of branches; number of pods; number of grains per pod; productivity (kg/ha) and germination. Significant interactions were found for the variables in the amount with three and four grains per plant, in the number of grains per plant and number of pods per plant. According to the data obtained, it was concluded that the lower population density (160,000 plants/ha) tends to present better values of the components of soybean yield with the foliar applications of the algae-based biostimulant Ascophyllum nodosum (Carboplex®), and there was also a significant increase in some variables that constitute the components of productivity, with greater formation in the number of larger pods.