FOLIAR SPRAYING OF A SEAWEED-BASED BIOSTIMULANT IN SOYBEAN

Biostimulants currently available on the market include those containing seaweed extract. There is sufficient scientific evidence to conclude that applying biostimulants to agricultural crops can positively impact plant growth and yield. However, results differ between plants species and environmental conditions. As such, the present study aimed to assess the effects of doses and application times of a biostimulant based on seaweed (Ecklonia maxima) extract on the morphology and yield of soybean crops. The experiment was conducted in a field in the municipality of Uberaba, Minas Gerais state (MG), Brazil, in dystrophic red latosol. A randomized block design was used, with four repetitions, in a 3 x 5 factorial scheme consisting of three application times (phenological growth stages: V4, R1 and V4+R1) and five doses of foliar-applied biostimulant (0, 250, 500, 750 and 1000 mL ha(-1)). In general, biostimulant application influenced the number of branches, nodes, flowers, and pods on the soybean plants and, consequently, crop yield. A dose of 607 mL ha(-1) promoted a 6.1% greater grain yield (5379 kg ha(-1)) than that obtained without biostimulant spraying (5070 kg ha(-1)). Application in stage R1 resulted in plants with more flowers and pods.