Tratamento fitossanitário e polímeros em sementes de soja afetando a qualidade no armazenamento e a retenção do ingrediente ativo

Abstract

The initial establishment of soybean seedlings is important for the success of the growing process. For this, the treatment of seeds contributes providing greater protection to them, the polymers can increase this efficiency and reduce losses of chemicals. Another important aspect in relation to treated seeds is the influence of seed size and its quality as a function of storage period. The present study was divided in two articles, the first one was to evaluate the efficiency of the different forms of application of phytosanitary treatment associated to polymers in the retention of losses of products by leaching and in the physiological quality of the seeds. For the first article, two lots with seeds of different sizes were used and two treatments were applied: polymer associated to the phytosanitary treatment simultaneously in the same syrup and application of the layered polymer after the treatment, the treatments being formed as follows : Control = no treatment, Trat + pol = Phytosanitary treatment + polymer applied simultaneously, Trat / pol = Phytosanitary treatment + polymer applied in layers, Trat = Phytosanitary treatment. To evaluate the retention of the treatment by the polymer, an extractor was used and the quantification of the active ingredient thiamethoxam lecified was performed. For the physiological evaluation, germination, first count, emergence, accelerated aging, seedling length, seedling dry mass and moisture content tests were performed. As results of this article, it can be observed that the application of polymer associated with the phytosanitary treatment of seeds was efficient in reducing leach losses and there was no difference in the retention capacity and the physiological quality between the different forms of polymer application. The second article had as objective to evaluate the physiological and sanitary quality of the seeds during the storage. Two seed lots were differentiated by the sieve diameter and two forms of application of the products were applied: polymer associated to the phytosanitary treatment in the same syrup and application of the layered polymer after the phytosanitary treatment, being the treatments formed as follows: T1 = Control , T5 = Phytosanitary treatment + Laborsan polymer applied simultaneously, T6 = Phytosanitary treatment + Likoseed polymer applied simultaneously, T7 = Phytosanitary treatment + Laborsan polymer applied in layers, T8 = Polymer Laborsan, T3 = Likoseed polymer, T4 = Phytosanitary treatment, T5 = = Phytosanitary treatment + Likoseed polymer applied in layers. The seeds were stored under uncontrolled conditions. The evaluations were performed at times zero, 45, 90, 135 and 180 days after treatment. For the physiological and sanitary evaluation of the seeds the tests of first count, germination, emergence, radicle and hypocotyl length, dry mass and sanity test were performed. Seeds treated with phytosanitary products and / or polymers have higher germination and first counts in laboratory tests. Smaller seeds had higher first-count values and tended to decrease the emergence more quickly during storage. Seed treatment associated or not with polymers is efficient in controlling fungi during storage.