Harvest index has increased over the last 50 years of maize breeding

• DOI: 10.1016/j.fcr.2023.108991
• Publication Date: 2023-06-07T22:01:18Z
• Authors: Alejo Ruiz; Slobodan Trifunovic; Douglas M. Eudy; Cintia S. Sciarresi; Mitchell Baum; Gerasimos J.N. Da...; Elvis F. Elli; Georgios Kalogero...; Kyle King; Caio dos Santos; August Thies; Lia Olmedo Pico; Michael J. Castel...; Patrick S. Schnable; Christopher Topp; Michael Graham; Kendall R. Lamkey; Tony J. Vyn; Sotirios V. Archo...
• Keywords: Stover; Genetic gain; Plant Breeding

Quantifying historical changes in maize harvest index (HI), the fraction of above-ground biomass allocated to grain yield, can enhance our ability explain yield trends and estimate stover carbon inputs for sustainability assessments. However, HI genetic gain has not been primary focus previous era studies. The aim this study is knowledge gain. Our first objective quantify Bayer Crop Science Legacy hybrids investigate contribution breeding agronomic management. second develop a general-use model describe temporal evolution HI. We studied 54 commercial (103-day 111-day relative maturities) released from 1983 2020 across 13 environments, including plant density (current increasing rate) N-fertilizer (low sufficient N rates) treatments. was estimated at physiological maturity by destructively sampling plants. Then we synthesize new experimental data with literature findings (n = 16) provide robust estimate. Results showed that increased over years 0.516 0.571 103-day 0.537 0.584 hybrids. gains were similar environments management treatments within range, indicating increase attributed breeding. affected magnitude HI, but did not. results, combined 16 datasets, revealed 0.26% year−1 since 1964. accounts ca. 15% US Corn Belt past 50 years. last years, breeding, will support estimations studies, inform crop models better capture increases.