Desempenho produtivo da soja originada de lotes de sementes com diferentes níveis de vigor

Abstract

High vigor seeds provide rapid and uniform seedling emergence in the field, resulting in plants that have a higher yield potential. The research has been able to elucidate the relationship between seed germination and establishment of crops, but the same emphasis is not being given to studies to evaluate the behavior of the plants during the phenological cycle and production. This study aimed to verify the effect of varying the force level of seed lots on the growth of plants on yield components and soybean yield. Two soybean cultivars, NK 7059 RR and SYN 1059 RR, had their batch ranked levels of force 65%, 70%, 75%, 80%, 85%, 90% and 95% by accelerated aging test and sown in the field. The experiment was conducted at Fazenda Iruna located in Paraguay, during the harvest of 2014/15. The experimental design was a randomized block in a factorial 2x7 consists of cultivars and levels of force, respectively, with five repetitions. The results were submitted to variance analysis and when significant, the effects of cultivars were evaluated by the Tukey test, whereas the effects of the levels of force evaluated by polynomial regression. The increase in seed force causes linear increases in plant growth, number of pods per plant, number of seeds per plant, mass of thousand seeds and soybean yield. Soybean cultivars show different behaviors to the variation in the force level of the seeds to the mass of a thousand seeds and productivity, and, depending on the cultivar, every percentage point increase in seed force level is able to increase productivity up to 28.0 kg ha-1. Lots with low vigor reduce productivity by 26.5% .The use of seeds with force levels of 95% can increase soybean yield at 842 kg ha-1.