Genetic gains in grain yield and harvest index over a decade in maize hybrids in India

Abstract

Maize (Zea mays L.) is a major cereal crop globally, and its productivity has significantly improved over the decades due to the adoption of single-cross hybrids and targeted breeding strategies. This study is the first in India to quantify genetic gains in maize over time by evaluating hybrids released between 2005 and 2014 from both public and private sectors. Thirty maize hybrids were tested for grain yield (GY) and harvest index (HI) across multiple seasons. The results showed significantly modest genetic improvements for GY and HI, with newer/modern hybrids outperforming older ones. Annual genetic gains were estimated at 1.3% for GY (56.34 kg ha⁻¹ year⁻¹) and 1.02% for HI (0.004 units year⁻¹). GY was closely correlated with HI, indicating simultaneous improvement and correlated response in yield and HI gains. While private-sector hybrids performed slightly better, public-sector hybrids remained competitive. Overall, the findings highlight the success of India's maize breeding efforts and point to the importance of selecting for GY and HI to achieve further progress. This work lays a strong foundation for developing the next generation of high-yielding maize hybrids.