Updated February 9, 2021:
Over 500 breeding lines were evaluated in 2020 for test weight. Testing included multiple planting dates, multiple harvest dates and multi-state collaborations. Multiple planting and harvest dates were evaluated because seed quality, which may have an impact on test weight, is normally a concern based on how long mature plants remain in the field and when the plants matures. Often times unfavorable harvest conditions, i.e. increased rainfall, shorter day lengths and milder temperatures, occur later in the season. Planting and harvest dates were approximately two weeks apart. Harvesting occurred approximately 1 week after maturity when the center row was harvested, then approximately 2 and 4 weeks later the right and left outside rows were harvested, respectively. All plots have been harvested and are currently being processed for test weight, moisture, seed size, seed quality, fatty acid content, protein, oil and amino acid content. These tests include genotypes with high protein or high oil and there is a significant range of seed protein and oil (35-42% protein and 18-21% oil on 13% moisture basis) and substantial differences in seed sizes (7-20g per 100-seed). As these seed traits can potentially impact test weight, the results from the study should be valuable for making improvements to test weight in soybean. In addition, test weight is being collected all Southern Uniform Tests and USB Diversity Tests grown by collaborators for test weight. We hope to have data collection complete by the end of the year and data analysis complete by the end of February. This study will be repeated in 2021.