The researchers studied how to create better maize hybrids by combining different parent plants. They found that some hybrids showed a significant increase in plant height, cob size, and grain yield. One hybrid, DMR QPM 103 x CML 539, had the highest increase in yield. They also discovered that traits like cob diameter can predict grain yield. Most hybrids had genes that were more dominant than their parents, leading to better traits. Using inbred parent plants was more effective for improving the hybrids. Hybrids with parents that had high individual performance and medium genetic differences produced the best results.