TY  - JOUR
N2  - 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.
N1  - NOTE: Currently Okori, Patrick is scientist at ICRISAT(Malawi)
AV  - restricted
A1  - Gasura, E
A1  - Setimela, P
A1  - Edema, R
A1  - Gibson, P T
A1  - Okori, P
A1  - Tarekegne, A
TI  - Exploiting Grain-Filling Rate and Effective Grain-Filling Duration to Improve Grain Yield of Early-Maturing Maize
UR  - http://dx.doi.org/10.2135/cropsci2013.01.0032
JF  - Crop Science
SP  - 2295
Y1  - 2013///
ID  - icrisat7421
EP  - 2303
SN  - 0011-183X
VL  - 53
PB  - Crop Science Society of America
ER  -