GENOTYPE x ENVIRONMENT INTERACTION AND STABILITY OF RELEASED STRIGA RESISTANT SORGHUM [Sorghum bicolor (L.) Moench] GENOTYPES IN ETHIOPIA

The yield performance of sorghum cultivars is highly influenced by environmental factors and genotype x environment interaction; therefore interaction is the major concern to plant breeders to develop improved cultivars. Field experiment was conducted to evaluate striga resistant sorghum genotypes during the 2014 cropping season at Fedis,Meiso, Kobo,Pawi and Humera. The materials used in the study consisted of eight striga resistant sorghum genotypes representing the types widely grown in lowland areas. The treatments were laid out in a Randomized Complete Block Design (RCBD) and replicated three times. Data were collected on sorghum traits in accordance with the procedure outlined in the IBPGR/ICRISAT sorghum descriptor.The objectives of this study were to estimate the magnitude of genotype x environment interaction (G x E) for grain yield and yield attributes and determine yield stability of striga resistant sorghum varieties in low land areas of Ethiopia. The individual location analyses of variance showed that genotypic mean square were significant only at Meiso and highly significant at Kobo for grain yield. The combined analysis of variance test showed that environment, genotype, and genotype x environment sum squares contributed 5.96%, (41.47%) and (41.81%) for grain yield respectively. The combined analysis of variance revealed significant variation among entries for most of the traits considered. From twelve characters the environment effect was highly significant for days to flowering and stand count at harvest and significant for days to maturity and thousand seed weight. Grain yield was positively and significantly correlated with panicle weight and panicle exertion. Based on the mean performance Abishir,Gobye and Birhan gave higher mean grain yield of 2.85, 2.82 and 2.69 ton ha- 1 respectively and the lowest yield was obtained from N-13 and SRN-39 2.28 and 2.27 ton /ha respectively. Generally, this study showed the importance of testing striga resistant sorghum genotypes for their yield and stability across diverse lowland areas of Ethiopia