The researchers studied how different combinations of red and blue light affect the growth and photosynthesis of tomato seedlings. They used LED lights to test seven treatments on tomato plants. Red light helped the plants grow taller and increased leaf size, while blue light inhibited growth but increased certain types of chlorophyll. The best results were seen with a combination of red and blue light, with the 3R1B treatment leading to the highest plant mass, chlorophyll content, and photosynthetic performance. Overall, the combination of red and blue light improved the growth and photosynthesis of tomato seedlings, especially with the 3R1B treatment.