Characterization of the physiological quality of soybean seeds produced in Santa Catarina State

Abstract

The soybean seeds produced in Santa Catarina have the potential for the application of new marketing strategies because they have superior quality over the minimum standards established by the Brazilian legislation. This potential was verified using time series analysis (TS). The main goal of this study was to characterize the physiological quality of soybean seeds produced in the State of Santa Catarina using data from the last five harvests in order to establish new commercialization strategies based on seed quality. Historical data for germination and vigor were obtained from the 2012/2013 to 2016/2017 harvests, with a total of 4606 lots studied. To validate the historical data, data from the 2016/2017 harvest were included. For this analysis, 100 lots of soybean seeds from the 2016/2017 harvest were collected, and laboratory tests for germination and vigor were performed. The results of the time series analysis showed that, on average, the germination rate ranged from 89 to 93%, with all values being higher than the minimum required for commercialization by the Brazilian legislation. Vigor ranged on average from 82 to 90%. Currently, there is no reference value for vigor in the Brazilian legislation for seed commercialization purposes. Of the total of lots evaluated, 1%, 2%, 21%, and 76% of seeds presented germination < 70%, 70–80%, 80–90%, and > 90%, respectively, whereas 4%, 3%, 7%, 17%, and 69% of the lots presented vigor < 70%, 70–75%, 75–80%, 80–85%, and > 85%, respectively. Considering that 76% of the lots presented germination > 90% and 69% of the lots had vigor > 85%, the lots that presented these percentages were ranked, and 64% were determined to meet high quality standards. Taking into account the 100 sampled lots from the 2016/2017 harvest, 55% presented germination > 90% and 58% had vigor > 85%. In this harvest, 41% of the lots met the standards of at least 90% germination and 85% vigor according to the ranking methodology. This study concludes that due to the stability of climatic conditions, the State of Santa Catarina produces soybean seeds with physiological quality above the minimum standards, which allow the establishment of a minimum vigor standard of 85% for the commercialization of soybean seeds.