PREJUÍZOS DA MANCHA PÚRPURA PARA O DESEMPENHO DE SEMENTES DE SOJA

Abstract

In recent years, Brazil has stood out in soybean production, emphasizing the importance of understanding phytosanitary challenges to ensure seed quality. Purple seed stain, caused by the fungus Cercospora kikuchii, affects the pods, leading to spots that may impact the seeds. While some studies suggest that these spots do not reduce seed vigor, others report detrimental effects on seed quality. An adequate plant stand is essential to maintain high productivity in this crop. This study aims to quantify the impact of purple spot on seedling performance. It was conducted with a batch of soybean seeds that were initially divided into five sub-samples with different levels of purple spots on the seed coat. The sub-samples consisted of seeds with 0, 1 to 15, 16 to 30, 31 to 45, and 46 to 60% of seeds with spots on the coat. Subsequently, the moisture content, germination test, first count, and electrical conductivity were determined. The experimental design adopted was completely randomized. For the germination tests and first count, there was no significant effect of the percentage of seeds with spots. However, for the electrical conductivity test, it was observed that higher levels of spots resulted in seeds with a greater amount of electrolytes released into the soaking solution of the test. There is no reduction in the final germination of seeds with spots, but there is a reduction in the vigor of seeds with high levels of purple spots.