Gasura, EdmoreSetimela, PeterEdema, RichardGibson, Paul T.Okori, PatrickTarekegne, Amsal2022-05-262022-05-262013Gasura, E., Setimela, P., Edema, R., Gibson, P. T., Okori, P., & Tarekegne, A. (2013). Exploiting grain-filling rate and effective grain-filling duration to improve grain yield of early-maturing maize. Crop Science, 53, 2295-2303. doi: 10.2135/cropsci2013.01.003210.2135/cropsci2013.01.0032https://nru.uncst.go.ug/handle/123456789/3504Early-maturing maize (Zea mays L.) genotypes yield 15 to 30% less than late-maturing genotypes. One strategy for improving grain yield in the early-maturing group involves assessment of grain-filling traits as secondary traits for selection for high grain yield. In this study, we investigated the possibility of using grainfilling rate and duration for improving grain yield in early-maturing tropical maize. Forty-four hybrids generated using North Carolina design II were evaluated at CIMMYT-Zimbabwe during the 2011/2012 season under irrigated and nonirrigated environments. Although grain-filling rate and effective grain-filling duration were negatively correlated, several hybrids were distinctly above the trend line. The earliest-maturing hybrid took 127 d to reach physiological maturity and produced grain yields comparable to those of the medium-maturing genotypes (7 t ha-1). It had a high grain-filling rate of 2.40 g per plant d-1 (18% higher than those of the lowyielding hybrids) and a relatively longer effective grain-filling duration. Grain-filling rate and effective grain-filling duration had high coefficients of genetic determination, positive correlations with grain yield, low error terms, and low genotype × environment interactions, making them appropriate selection traits for improved grain yield. The study shows that it is possible to develop high-yielding early- to medium-maturing maize hybrids based on favorable combining ability values for grain-filling rate and duration.enGrain-Filling RateGrain-Filling DurationGrain YieldEarly-Maturing MaizeArticle