INFLUENCE OF SOYBEAN SEED MOISTURE CONTENT IN THE RESPONSE TO SEED TREATMENT IN SOYBEAN

Abstract

Seed treatment (ST) is an important practice for soybean crop. This research had the objective to evaluate the influence of seed moisture content in the response to different spray volumes (SV) used for seed treatment in soybean, considering effects on seed physiological quality. Three seed lots with distinct moistures were used: 7.2%, 10.1% and 13.0%. Untreated seeds (control) and three SV were tested: 8, 13 and 18 mL kg-1. All lots received the same treatment combination, containing insecticide, fungicide, fertilizer and biostimulant. This combination represented 8 mL kg-1 of SV; the doses of 13 and 18 mL kg-1 were obtained by adding 5 and 10 mL kg-1 of water, respectively. Evaluations of seed physiological quality consisted of electrical conductivity, seed respiration, germination and vigor tests. Results of all tests demonstrates that low-moisture soybean seeds (7.2%) are negatively affected by seed treatment within an SV range of 8 to 18 mL kg-1, while untreated seeds with equal moisture are not affected. Oppositely, high-moisture seeds (13.0%) are not affected by the SV tested, while intermediate-moisture seeds (10.1%) are affected by the higher SV. This result highlights seed moisture as a key parameter to be managed before soybean ST, aiming to maintain a high physiological quality.