Abstract

Sorghum is one of the most important cereal crops in Ethiopia. However, the productivity of this important crop is low owing to different factors, of which Striga is most detrimental. Multi-environment performance evaluation was carried out consisting of 11 sorghum genotypes. The objective was to select better performing, Striga-resistant and stable sorghum lines. The trial was conducted at three Striga prone areas of North-east Ethiopia for two years. The result of combined analysis of variance across locations over the years showed that genotype × location × year of interaction significantly affected all traits except days to heading, which indicate the inconsistency of the genotypes in different locations and cropping seasons. All the genotypes supported significantly lower number of Striga than the susceptible and local checks. Log transformed value of Striga count ranged from 1.41 for G5 to 2.71 for G10. The performance of the genotypes on individual locations showed that G7 was the highest yielding genotype, followed by G9 on environment Kobo 03. The additive main effect and multiplicative interaction (AMMI) analysis of variance showed that the total G×E variance was explained by three significant interactions principal component axes (IPCAs), which contributed 95.8% in total, while the genotype and genotype by environment (GGE) explained 90.18% of the G×E variance. Based on Striga resistance, agronomic performance and yield stability of genotypes, G7, G8 and G9 were found to be better sorghum genotypes for the area under consideration. Genotype G9 is a brown seeded and short-stalked released variety; whereas G8 (Gambella1107 × P-9403), as it was preferred by farmers, has been released by the name Gedo for production in the Striga prone areas of North-eastern part of Ethiopia. The three genotypes could be used as sources of Striga-resistance in future crossing programs.

Key words: Additive main-effect and multiplicative interaction (AMMI), desirable genotype, genotype and genotype by environment (GGE), interaction principal component axes (IPCAs),  Striga hermonthica.