Armazenamento seguro (“seed safety”) de sementes de milho tratadas com inseticidas em função da temperatura

Abstract

Sanitary treatment is a consolidated technique to preserve the quality of seeds against damage caused by pests and diseases, favoring the establishment of the stand in the field. However, seed treatment prior to sowing followed by storage, a necessary practice in industrial seed treatment (TSI), can affect seed quality. That is why knowledge of the active ingredient, storage and maintenance of quality (“seed safety”) relationship is necessary. The objective was to evaluate the effect of industrial treatment of corn seeds with insecticidal molecules on the physiological quality during storage at different temperatures. Seeds of the hybrids BM950 PRO3 and BM709 PRO2 were subjected to industrial treatment with insecticides based on Chlorantraniliprole, Cyantraniliprole, Clothianidin and Control, stored at different temperatures (10, 20 and 30 °C) for different periods (0, 90, 180, 270 and 360 days), composing a 4x3x5 factorial scheme, for each hybrid, in a completely randomized design. To assess the physiological quality of the seeds the following tests were performed: moisture content, germination, first germination count, germination with vermiculite, first germination count with vermiculite, seedling emergence under controlled conditions, seedling emergence speed index, accelerated aging with germination in paper, accelerated aging with seeding in substrate and cold test. Seed treatments do not affect the germination potential during storage, even after 360 days in different environments. At low temperatures, insecticides are not harmful to vigor during storage, however, at 30 °C the deterioration is significant, especially after 180 days. After 180 days at 30 °C, there is a greater phytotoxic effect on vigor when using the treatment based on Clothianidin compared to the others. Higher temperatures favor the seed degradation process and enhance the phytotoxic effect by insecticidal molecules.