Qualidade de sementes de soja com diferentes teores de lignina obtidas de plantas submetidas à dessecação

Abstract

The dessication is a technique by which the goal is to anticipate the harvest soybean seeds in order to prevent them from being exposed to adverse conditions in the field and thus have the quality impaired. However, some herbicides used in this technique can reduce seed quality, and among the factors that may contribute to minimize this damage, the impermeability of the seedcoat, associated with the lignin content has shown in some studies related to the quality of seeds. Thus, the need for studies to elucidate the relationship between these factors and quality of soybean seeds, this study aimed to evaluate the influence of lignin content in the integument of different soybean cultivars, the physiological and sanitary quality of seeds obtained from dried plants with different herbicides at different stages of development. Plants of BRS Silvânia RR, BRS Valiosa RR, BRS 245 RR and BRS 247 RR were desiccated with herbicides, plus the control (water), applied between stages R7 and R8, when seeds had 30, 40 and 50 % of water content. After harvest, we determined the productivity and lignin content in the seed coat. For the evaluation of seed quality tests were conducted for germination, emergence, speed of emergence, accelerated aging, electrical conductivity, tetrazolium and sanity. Some of the seeds were stored at ambient conditions and after 180 days were subjected to the same test. We observed a link between the lignin content and quality of seeds. For most tests the seeds of cultivars with low lignin content in the seed coat showed superior when compared to high grade. The use of the herbicide Finale® negatively affect the physiological quality of seeds.