Evaluation of genetic gains, grain yield potential, and agronomic performance of ultra-early maize hybrids under drought stress

Author

Hondo, N.

Title

Evaluation of genetic gains, grain yield potential, and agronomic performance of ultra-early maize hybrids under drought stress

Abstract

Maize (Zea mays L.) is a crucial staple crop globally. Its production has been severely constrained by drought, which has been worsened by climate variability. Drought occurrence is expected to become more frequent; hence, the implementation of adaptive measures such as developing drought-tolerant maize hybrids is of paramount importance. In such a way, assessing genetic gains in the maize breeding programs will allow monitoring of breeding efficacy and genetic progress. The present study was conducted to evaluate the performance of newly developed ultra-early maturing maize hybrids for grain yield potential, agronomic performance, and genetic gains. Twenty-five genotypes consisting of 10 experimental hybrids and 15 commercial check hybrids were evaluated across six sites laid out in a 5 x 5 alpha lattice block, replicated three times per site. The results showed a significant variation in grain yield and most measured agronomic traits across sites (p<0.05). The hybrid named EXP5 had the highest yield, 2.14t/h. Positive realised genetic gains of selected genotypes over the population's mean, the best commercial check, and the mean of all checks were obtained for grain yield and most measured traits. The selected hybrids had a 28.8% gain on grain yield over the mean of the population, and 38.5% over the mean of all commercial checks. This showed a great improvement in grain yield performance in newly developed ultra-early maize hybrids.EXP5, EXP7, EXP2, and EXP9 were recommended for advancement to the next stage for further testing due to their high performance. The study's findings demonstrated the progress in breeding drought-tolerant varieties with desired agronomic traits in Seed Co's maize breeding programs. They also reflected the need for continuous investment in maize breeding programs to achieve higher realised genetic gains. Results from the study will add to the existing knowledge on ultra-early maize hybrids as an important step towards climate change adaptation.

Date

OCTOBER 2025

Publisher

BUSE

Keywords

Drought

Ultra-early maize hybrids

Genetic gains

Grain yield potential

agronomic traits

Supervisor

Mr. K. Mutsengi