A global analysis of dry matter accumulation and allocation for maize yield breakthrough from 1.0 to 25.0 Mg ha−1

Feeding a growing population requires improving crop yield without compromising the environment. Maize (Zea mays L.) is the largest food crop in the world. Identifying underlying drivers that increase maize yield is not only important for food security but also high resources use efficiency and environmental sustainability. Dry matter (DM) accumulation and its allocation to kernels are key factors that determine the final maize grain yield. To clarify the characteristics of DM accumulation, and allocation for maize yield breakthrough, data from previous publications from the 1970s to 2020s were collected and analyzed in combination with data from five years’ field experiment conducted with six maize cultivars once yielding the highest in China and in all previous publications globally. As grain yield increased from 1.0 to 25.0 Mg ha−1, a longer growth duration was essential, especially post-silking duration. A large but not excessive maximum leaf area index (LAI, 6.74) at silking was needed for crowded populations, and a relatively large LAI (3.35) at maturity was necessary. The pre-silking DM plateaued at 13.49 Mg ha−1 when grain yield exceeded 17.0 Mg ha−1. The proportion of post-silking DM to total DM increased with yield and was about 70% when the yield level was 25.0 Mg ha−1. By contrast, the DM transfer rate decreased with increasing yield. In addition, the harvest index (HI) could be further increased from a steady 0.52 to 0.55 when grain yield exceeded 10.1 Mg ha−1. These innovative findings are of great significance for yield breakthrough and high resources use efficiency.