The researchers aimed to understand how different maize plants combine their genetic traits when crossed with each other under varying irrigation intervals. They used five inbred maize lines in a breeding program and found significant differences in the combining abilities of the parent plants and their hybrids for traits like flowering and grain yield. One inbred line, ZM4, showed the highest negative combining ability for female flowering, while another, MH121, had the highest positive combining ability for grain yield. Specific hybrids also showed varying combining abilities, with one hybrid, AG116 × AGM20, having the highest positive combining ability. Overall, the study highlights the importance of genetic interactions in maize breeding and how irrigation intervals can affect these combinations.