Agronomic Performance and Adaptability of Advanced Highland Maize Hybrids
Maize is crucial a cereal, widely grown globally, and has significant potential to improve the livelihoods of millions of people in developing countries. High-yielder and well adapted maize hybrids are a valuable approach to improve productivity. The study was proposed with the objectives of (i) evaluating and selecting the high-performing hybrids in terms of yield and yield-related traits for the highland agroecology of Ethiopia and (ii) identifying representative and/or discriminative highland maize hybrids' testing locations and stable hybrids across environments. During the 2023 cropping season, twenty-seven genotypes and three hybrid checks were evaluated in a row-column design with three replications across six locations. Analysis of variance across locations revealed significant differences in genotype, environment, and genotype-by-environment interaction for all measured traits, except for silking date, plant height, and ear aspect. Hybrids such as 3XH2000090 (10.2 t ha-1) and 3XH2000110 (10.1 t ha-1) were high-yielding with a yield advantage of 16.5 % over the best hybrid checks. The GGE biplot analysis identified hybrids such as 3XH2000051, 3XH2000058, 3XH2000091, and 3XH2000097, which exhibited comparable yield performance across environments. The AMMI analysis also supported this finding, identifying 3XH2000051, 3XH2000091, 3XH2000090, 3XH2000035, and SXH1800174 hybrids with high yield and stability across environments. Considering mean grain yield and stability, these hybrids could be verified and released for wider environments. Adet, Jimma, and Holeta were the discriminating and representative testing environments used to identify hybrids that excel in particular locations. Ambo, Kulumsa, and Haramaya University were highly representative mega-environments. When resources are limited, these representative environments could be used interchangeably to evaluate maize hybrids for the highland agroecologies of the country.