Origin of yield gains in maize hybrids

Abstract Increasing grain yields in maize ( Zea mays L.) have been widely witnessed over the lifespan of many aging farmers. This paper aims to capture and summarize the overlapping explanations for the significant increases in maize yields. Changes in management practices have resulted in higher planting densities; however, genetic alterations allowed for maize varieties to tolerate increased stress levels. Increased stress levels, such as light availability, prompted genetic changes to leaf area index, radiation use efficiency, and leaf angles. The narrowing of the anthesis–silking interval is more significant in maize planted in higher densities. Stress factors affecting maize grain yields can be managed by both management changes such as water or pesticide application, and breeding modifications, such as genetic resistance to abiotic, temperature, or moisture, and biotic, pest, disease, and insect stressors. The increase in maize grain yields over the past century can be attributed to a combination of achievements in crop breeding and alternations of management practices.