Rasgo no tegumento: repercussão na qualidade fisiológica em sementes de soja

Abstract

Soybean production has grown steadily over the last few years. In order to guarantee these high levels of production, major investments have been made in the development of new cultivars, as well as an increase in the level of technology used by producers. Despite all these advances, a determining factor in guaranteeing productivity is a good initial plant stand in the fields, which is easier to achieve using seeds with guaranteed genetic, physical, health and physiological qualities. The seed coat plays an important role in maintaining quality, but in some varieties there is a rupture or tear in the seed coat which can compromise the maintenance of the seed's attributes. The aim of this study was to compare the behaviour of seeds with and without tears in the process of gaining and losing moisture, and the ability to homogenize the distribution of chemical products around the seed. For this purpose, the seed soaking/hydration test was used, subjecting the seeds directly to water or to humid environments such as duly moistened paper simulating a germination test and gerboxes with the humid environment saturated according to the indications of the accelerated ageing test, assessing the absorbed water content. Another analysis carried out was electrical conductivity, which assesses the release of ions leached into the environment as the seed absorbs water, and the more it releases, the faster its physiological quality will be lost during storage. Lastly, the seeds were subjected to seed treatment, following the industry standards for commercialization and evaluating the responses to twinning and vigor at the end of this process. It can be concluded that seeds with tears tend to absorb water more quickly and consequently leach their reserves more quickly, tending to lose quality more quickly. The use of chemical products on seeds with tears can compromise their physiological quality.