Premium
Exploiting Grain‐Filling Rate and Effective Grain‐Filling Duration to Improve Grain Yield of Early‐Maturing Maize
Author(s) -
Gasura Edmore,
Setimela Peter,
Edema Richard,
Gibson Paul T.,
Okori Patrick,
Tarekegne Amsal
Publication year - 2013
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2013.01.0032
Subject(s) - hybrid , agronomy , biology , yield (engineering) , grain yield , grain size , zoology , materials science , composite material
Early‐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 grain‐filling 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 low‐yielding 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.