The researchers in Nigeria studied how planting maize with different legumes affected crop yields. They found that some legumes, like Popondo and Mucuna, reduced maize yields, while others, like calopo, cowpea, and greengram, had less impact on maize and were tolerant to shade. Maize yields were highest when interplanted with these legumes, even without fertilizer. Legumes did not affect maize yields much, but their own yields were lower due to maize shading. Overall, intercropping maize with certain legumes can help maintain high maize yields in Western Nigeria.