Qualidade fisiológica e rendimento de sementes de soja submetida a diferentes épocas de dessecação

Abstract

The desiccation is a technique that aims hasten the harvest in order to prevent the seeds from suffering excessive damage, deterioration and loss in physiological quality as a function of the storage field. Therefore, this study aimed at assessing the most appropriate time for the application of Diquat desiccant at different growth stages of soybean, as well as their interference on final yield and physiological seed quality. For this, 5 treatments with 5 replicates in completely randomized design, with treatments were performed: desiccation in R 6, in R 7.1, in R 7.3 and in R 8.2, plus control - R9 (without desiccation). The samples were subjected to analysis by the germination test, by the parameters the vitality first count (%) and germination (%); tetrazolium test, considering feasibility (%), vitality (%) and damage caused by moisture (%) and the final yield, through the thousand seed weight (g) and yield (kg ha-¹). Conclude that if production of a crop a soybean for use as seed, the best time to desiccation with Diquat would be the R 6 stage, due to the higher germination and vigor; although it becomes unfeasible due to the damage caused at the time of harvest, mainly by high humidity. On the other hand, if the aim is grain, application should be made in later stages, preferably in R 8.2, in view of the uniformity of maturation and increased productivity.