Use of GGE biplot for targeting early maturing maize cultivars to mega-environments in West Africa

Maize (Zea mays L.) is an important staple food consumed by people with varying food preferences and socio-economic backgrounds in West Africa (WA). Genotype by environment interactions (G 7E) exist in WA implying the need for extensive testing of cultivars in multiple environments over years before cultivar realistic recommendations can be made. This study examined the effect of G 7E on the performance and stability of early cultivars and to identify core test locations in the mega-environments of WA. Across locations, 2004 TZE-W Pop STR C4 produced the highest grain yield and was the most stable cultivar. DMR-ESRW QPM produced the lowest yield. The test environments contributed about 83.4% of the total variation in grain yield, while genotypes accounted for 1.5% and G 7 E, 11%. Test environments were classified into four mega-environments, namely, Katibougou, Sotouboua, Ejura, and Bagou as the first group; the second group consisted of Manga, Nyankpala, Bagauda, Yendi, Angaredebou, Mokwa, Katibougou, and Zaria; while the third group comprise of Ativeme, and Ikenne; and the fourth, Ina. Test locations Ejura, Sotouboua and Bagou and Katibougou were highly correlated in their ranking of the genotypes in group 1, suggesting that a promising early maturing cultivar selected in one of these locations in one country will also be suitable for production in the other locations within the same mega-environments in different countries. Kita was identified as the ideal location, while Zaria was close to the ideal location.Le ma\uefs (Zea mays L.) est une nourriture principale consomm\ue9 par des personnes \ue0 pr\ue9f\ue9rence alimentaires et un pass\ue9 socio-\ue9conomique vari\ue9s en Afrique de l'Ouest. Une interaction G\ue9notype et Environnement (G 7E) \ue9tait trouv\ue9e, impliquant ainsi le besoin en test extensive des cultivars sur plusieurs ann\ue9es avant toute recommandation. Le but de cette \ue9tude \ue9tait d'examiner l'effet G 7E sur la performance et la stabilit\ue9 des cultivars pr\ue9coces, ainsi que d'identifier le test principal de milieu dans les m\ue9ga-environnements de l'Afrique de l'Ouest. A travers les milieux, 2004 TZE-W Pop STR C4 avait produit le rendement en grain le plus \ue9lev\ue9 et \ue9tait le cultivar le plus stable. DMR-ESRW QPM avait induit le rendement le moins \ue9lev\ue9. La contribution du test d'environnements \ue9tait d'environ 83.4% de la variation totale du rendement en grain, pendant que les g\ue9notypes et G 7 E pr\ue9sentaient 1.5% et 11%, respectivement. Les tests d'environnements \ue9taient classifi\ue9s en quatre m\ue9ga-environnements \ue0 savoir, Katibougou, Sotouboua, Ejura, and Bagou comme premier groupe; Manga, Nyankpala, Bagauda, Yendi, Angaredebou, Mokwa, Katibougou, and Zaria comme deuxi\ue8me groupe, alors que le troisi\ue8me groupe comprenait Ativeme, et Ikenne et le quatri\ue8me, Ina. Le test de milieux Ejura, Sotouboua, Bagou et Katibougou \ue9taitent hautement corr\ue9l\ue9 sur le plan ranking des g\ue9notypes au sein du groupe 1, sugg\ue9rant qu'un cultivar pr\ue9coce promettant s\ue9lectionn\ue9 dans un de ces milieux dans un pays sera appropri\ue9 pour la production dans d'autres milieux au sein des m\ueames m\ue9ga-envoronnements dans diff\ue9rents pays. Kita \ue9tait identifi\ue9 comme un milieu ideal, alors que Zaria \ue9tait proche du milieu ideal

Use of GGE biplot for targeting early maturing maize cultivars to mega environments in West Africa

Maize (Zea mays L.) is an important staple food consumed by people with varying food preferences and socioeconomic backgrounds in West Africa (WA). Genotype by environment interactions (G×E) exist in WA implying the need for extensive testing of cultivars in multiple environments over years before cultivar realistic recommendations can be made. This study examined the effect of G×E on the performance and stability of early cultivars and to identify core test locations in the mega-environments of WA. Across locations, 2004 TZE-W Pop STR C4 produced the highest grain yield and was the most stable cultivar. DMR-ESRW QPM produced the lowest yield. The test environments contributed about 83.4% of the total variation in grain yield, while genotypes accounted for 1.5% and G × E, 11%. Test environments were classified into four mega-environments, namely, Katibougou, Sotouboua, Ejura, and Bagou as the first group; the second group consisted of Manga, Nyankpala, Bagauda, Yendi, Angaredebou, Mokwa, Katibougou, and Zaria; while the third group comprise of Ativeme, and Ikenne; and the fourth, Ina. Test locations Ejura, Sotouboua and Bagou and Katibougou were highly correlated in their ranking of the genotypes in group 1, suggesting that a promising early maturing cultivar selected in one of these locations in one country will also be suitable for production in the other locations within the same mega-environments in different countries. Kita was identified as the ideal location, while Zaria was close to the ideal location