The researchers studied different types of corn to see how their genetic traits affect grain yield. They grew 20 varieties in a specific design and found that factors like cob weight and plant height had significant differences among the varieties. Some traits, like grain yield and cob weight, showed high variability, while others like moisture content and days to maturity had moderate variability. They also found that traits like grain yield and plant height are strongly influenced by genetics rather than the environment. Overall, the study suggests that genetic factors play a big role in determining the productivity of corn plants.