Soybean plants with higher yields have leaves that are thicker, contain more chlorophyll, and have a higher rate of photosynthesis compared to plants with lower yields. This means that the more productive soybean varieties are better at turning sunlight into energy for growth. Scientists found that the amount of yield is closely linked to how efficiently the plants can photosynthesize. By using advanced technology, researchers can quickly and accurately measure the photosynthetic rate of soybean plants, which can help breeders select for high-yield varieties in the future.