Soybean cultivars differ in grain yield based on how much sunlight they capture. Researchers studied four cultivars at different growth stages to see how well they intercepted solar radiation. They found that cultivars with better sunlight interception in the plant canopy had higher grain yields. Plants with lower sunlight interception in the lower part had more infertile nodes, affecting yield. The maximum sunlight interception observed was 5.2% in the lower part of the plants.