GENOTYPE by ENVIRONMENT INTERACTION AND YIELD STABILITY OF MAIZE (Zea mays L.) GENOTYPES IN MAJOR MAIZE GROWING AREAS OF ETHIOPIA

Abstract

Conducting multi-location trials along with the commercial varieties and genotype by environment (G x E) data analysis are vital to breeders to develop superior genotypes and to meet the challenges posed by environmental factors. This research was undertaken to evaluate maize hybrids for yield and yield related traits, assess the effect of G x E on grain yield, and determine the yield stability of hybrids across major maize growing areas of Ethiopia. A total of 24 maize hybrids including standard checks(BH547,BH547,BH661and Limu) were evaluated at six locations (Bako, Jimma, Pawe, Ambo Wendogenet and Asosa) in randomized complete block design (RCBD) with three replications during the 2020 cropping season. The hybrids had significant differences for most of the traits at all locations. The mean squares for genotype, location and G x E were significant for all traits, except G x E for plant height. The mean grain yield of maize hybrids across the six environments ranged from 4.11 t/ha at Wendogenet to 9.11 at Bako. The analysis of variance from Additive Main Effects and Multiplicative Interaction (AMMI) model for grain yield showed significant (P<0.01) effect of environment, genotype, G x E, PC1 and PC2. Environment, genotype, and G x E interaction accounted for about 58.64, 11.78, and 22.03% of the total sum of squares, respectively. The two principal components axes (PC1 and PC2) contributed 62 % to the total sum square of G x E. The SXM1910007 hybrid had the highest yielding of all genotype with mean grain yield of 8.68 t/ha that had showed dynamic stability. The two hybrids, WE3106 and WE7131 had mean grain yield of 8.06 t/ha and 7.98t/ha, respectively, which was higher than best commercial checks. These hybrids along with other two hybrids (WE3105and 3XM1900476) were identified as most stable hybrids for yield by AMMI stability value, GGE bi plot, yield stability index and other stability parameters. In conclusion, the identified desirable maize hybrids could be used as candidate varieties for cultivation in major maize growing areas of Ethiopia. However, the identified hybrids need to be further evaluated under verification trial over many locations to be recommended as commercial varieties