Tratamento químico de sementes de soja: processos de aplicação e qualidade das sementes

Abstract

Chemical seed treatment is a widely used technique in soybean production, but the relationship between this technology and the physiological quality of seeds must be considered, especially when seed storage after treatment is necessary. Some molecules used in seed treatment can impair the physiological quality due to the anticipation of the treatment, assertiveness of the treatment dose, constitution and formulation of the final volumes of the syrup used in the soybean crop. Thus, three studies were carried out with the objectives of identifying and quantifying the effects on the physiological quality of stored seeds as a function of the assertiveness of the insecticide dose, constitution and final volumes of the treatment mixture; evaluate the effect of phytosanitary and functional products used in the treatment on the quality of stored soybean seeds; and to evaluate methodologies and parameters for validating the use of high-resolution computerized image analysis in the evaluation of coating of treated soybean seeds, as well as to characterize the profiles of coating quality and dose assertiveness in seeds treated “On-Farm” and via IST in Brazilian agribusiness. The effects of the association between insecticide dose error, high aqueous spray volume and prolonged storage period are additive and detrimental to the physiological quality of treated seeds. The addition of Co-Mo + Inoculant + Graphite components, in addition to the quality of phytosanitary products, interfere with the physiological quality of the seeds after 30 days of storage. The excessive number of products via seed treatment can negatively affect their quality, even with a short storage period, 15 days, evidenced mainly by vigor. The composition of the treatment directly affects the detachment of dust (Dust-off) of the seeds. Image analysis is efficient for quantifying the coverage of treated soybean seeds, regardless of color dominance. Seed coating is directly related to dose assertiveness. There is heterogeneity between “On-Farm” samples, with failures in coverage and dose assertiveness, while TSI samples have a greater tendency towards high coverages and dose assertiveness, with a predominance of homogeneous results close to those recommended, but with some exceptions of samples “On-Farm”.