Bioregulator application, agronomic efficiency, and quality of soybean seeds

Abstract

The application of vegetal bioregulators has shown promising results, mainly in cultures that have already reached a high level of technology. Based on this context an experiment was carried out with the objective of evaluating agronomic traits of plants, such as yield and quality of seeds, produced by applying bioregulators to a soybean crop. For this purpose, the following treatments were carried out: before sowing - seed treatment (25, 50 and 75 mL for 100 kg-1 seeds); during sowing time - spraying on the sowing lines (pulverization onto the sowing lines) (50, 100 and 150 mL ha-1); between stages V5 and V6 (25, 50 and 75 mL ha-1); and the control - no treatment. Emergence speed, final seedling emergence, number of pods and seeds per plant, average height of plants, first pod insertion height, duration of the cycle, final stand, degree of plant layering, and the yield and weight of one thousand seeds were evaluated. The quality of seeds was evaluated based on germination, classification of seedling vigor, tetrazolium, health test and the quantity of oil and protein tests. The highest yield of grains, an increase of 92% as compared to the control, was obtained when using the product at a dose of 75 mL ha-1. The best quality seeds and the highest oil and protein content were obtained from seeds produced by plants whose seeds were treated before sowing time using the bioregulator (75 mL for 100 kg-1 seeds).