Genotype–genotype × environment (GGE) biplot analysis of extra-early maturing quality protein maize hybrids for grain yield

Extra-early-quality protein maize with short maturity period has potential of alleviating protein deficiency and fostering food security among vulnerable people in sub-Saharan Africa. GGE biplot analysis was used to assess forty-five extra-early-quality protein maize hybrids to identify high-yielding and most stable hybrid across environments. The forty-five extra-early-quality protein maize hybrids and two commercial checks were evaluated at three locations (Ibadan, Ile-Ife and Kishi) for two years under rain-fed conditions, making six environments in humid agro-ecologies of Nigeria. Data were collected on grain yield and other agronomic traits, and were subjected to analysis of variance. The results obtained showed that that coefficient of variation ranged from 3.1% (days to anthesis) to 45.6% (grain yield) across locations. The grain yield (kg ha−1) ranged from 1064.72 (Ibadan) to 2175.03 (Kishi), while days to anthesis and days to silking varied from 49.38 and 52.99 (Kishi) to 52.15 and 56.83 (Ibadan), respectively. Genotype, environment and genotype × environment interaction had significant effect on grain yield, where genotype, environment and genotype × environment accounted for 67.0%, 32.6%, 0.12%, respectively of the total variation. This suggests that grain yield of the extra-early-quality protein maize hybrids evaluated was mainly under genetic effect than environmental influence. GGE biplot analysis revealed that hybrid TZEEQI 9 × TZEEQI 16 was adjudged as the most stable and high yielding across locations (ideal genotype), while Ibadan was regarded as ideal environment to discriminate stable hybrids. Therefore, hybrid TZEEQI 9 × TZEEQI 16 can further be tested in multi-locations before recommendation to the farmers in southwestern Nigeria. © 2022, The Author(s), under exclusive licence to Korean Society of Crop Science (KSCS).