Effect of carbon dioxide, temperature and storage on soybean seeds and associated mycoflora

The vegetative and reproductive development of the soybean is related to the production technology of good quality seeds which are vigorous and free of pathogens. Thus, this study aimed to evaluate the effect of carbon dioxide (CO2) associated with temperature on mycoflora and seed quality for different periods of storage. The design used was a completely randomized factorial (2 x 3 x 4), at two temperatures (25 and 31 °C), three CO2 concentrations (0.0, 2.5 and 5.0 g CO2 kg-1of seed), and four storage periods (30, 60, 90 and 120 days). According with results, it was observed that carbon dioxide was extremely toxic to the fungi Aspergillus sp., Fuzarium sp., Coletrochium sp. and Penicillium sp., with 100% inhibition at a concentration of 5 g CO2 kg-1 of seed, and at temperatures of 25 and 31 °C. Seed germination and vigor were preserved by the carbon dioxide, with 92% germination after 120 days of storage, while for seeds stored without CO2 at a temperature of 31 °C, germination was 44.66%. The preservation of vigor and germination was dependent on the concentrations of CO2 and on temperature. CO2 may be a viable technology for the preservation of the quality of soybean seeds for seed-processing units in the state of Tocantins.