Performance of extra-early maize cultivars based on GGE biplot and AMMI analysis

2011

English

Multi-environment trials (METs) in West Africa have demonstrated the existence of genotype× environmentinteractions (G×E), which complicate the selection of superior cultivars and the best testing sites for identifyingsuperior and stable genotypes. Two powerful statistical tools available for MET analysis are the additive maineffects and multiplicative interaction (AMMI) and the genotype main effect+G×E (known as GGE) biplot. Theobjective of the present study was to compare their effectiveness in identifying maize mega-environments andstable and superior maize cultivars with good adaptation to West Africa. Twelve extra-early maturing maizecultivars were evaluated at 17 locations in four countries in West Africa from 2006 to 2009. The effects of genotype(G), environments (E) and G × E were significant (P<0·01) for grain yield. Differences between E accounted for0·75 of the total variation in the sum of squares for grain yield, whereas the G effects accounted for 0·03 and G× Efor 0·22. The GGE biplot explained 0·74 of total variations in the sum of squares for grain yield and revealed threemega-environments and seven cultivar groups. The AMMI graph explained 0·13 and revealed four groups each ofenvironments and cultivars. The two procedures provided similar results in terms of stability and performance ofthe cultivars. Both methods identified the cultivars 2004 TZEE-W Pop STR C4 and TZEE-W Pop STR C4 as superioracross environments. Cultivar 2004 TZEE-W Pop STR C4 was the most stable. The GGE biplot was more versatileand flexible, and provided a better understanding of G × E than the AMMI graph. It identified Zaria, Ilorin, Ikenne,Ejura, Kita, Babile, Ina and Angaredebou as the core testing sites of the three mega-environments for testing theRegional Uniform Variety Trials-extra-early.

Badu-Apraku, B.; Oyekunle, M.; Obeng-Antwi, K.; Osuman, A. S.; Ado, S. G.; Coulibay, N.; Yallou, C. G.; Abdulai, M.; Boakyewaa, G. A.; Didjeira, A.