The researchers studied how different planting dates and densities affected the growth and yield of two types of black soybeans. They planted the soybeans on May 21 and June 19, 1993, at various densities. They found that one variety had similar yields for both planting dates, while the other had lower yields when planted later. The planting date and density had significant effects on stem length, number of branches, seeds per plant, seed weight, and overall yield. The best planting date and density for high yield varied between the two varieties. The researchers also observed interactions between planting date and variety, as well as planting date and density. Overall, the study showed that planting date and density can greatly impact the growth and yield of black soybeans.