Abstract:
Tef is the most important staple cereal crop in Ethiopia. However, its productivity is low due to
several biotic and abiotic constraints. The diverse and dynamic environmental condition of
Ethiopia needs detailed and sustainable study of genotype by environment interaction (GEI)
for developed tef varieties. The objective of this study was to evaluate the genotype by environment
interaction for grain yield of different tef varieties and to identify stable and/or high yielding
genotypes across locations. Twenty-one tef varieties were tested at six environments/locations
(Jimma/Melko, Omonada, Bedele, Arjo, Areka and Ambo) in South and Southwestern Ethiopia
during the 2018 main cropping season using Randomized Complete Block Design (folded
RCBD) with three replications. Grain yield and other related traits were recorded and mean
performances of these traits and grain yield stability were evaluated using different statistical
procedures. The results showed significant differences among tef varieties for grain yield and yield
related traits. Combined mean grain yield of the tef varieties varied from 1084.3kg/ha for variety
Dukem, to 662.8kg/ha for variety Kena.The proportions of total sum of squares for environment,
genotype and GEI for grain yield were 69.4% 8% and 17.5%, respectively. Having the largest
proportion of sum of squares, the environment had the highest impact on genotype performance followed
by GEI and genotype. The Additive Main Effect and Multiplicative Interaction (AMMI) model also
demonstrated the presence of GEI. The first and second interaction principal components axes (IPCA)
highly significant (p<0.01) and cumulatively explained 63.4% of the total variation due to GEI.Stability
parameters such as Cultivar superiority measure, Stability variance, Yield stability index,AMMI
stability value, AMMI and GGE on average identified Heber-1 ,Quncho and Dukem as high yielding
and the most stable tef varieties.Whereas, Variety Kena, Wellenkomi, Negus, Felagot and Guduru as
low yielding and unstable varieties. Similar result was obtained from GGE biplots analysis showed that
Dukem as an ideal variety, while variety Heber-1 and Abola were desirable varieties as they were closer
to the ideal variety. Conversely, varieties Kena and Guduru were the least desirable varieties based on
GGE biplot. In general, the result of different stability parameters were differs in the selection of the
best performing and stable varieties. The results from this study gave valuable information for
researchers who were interested to examine the effect of G x E interactions on the performance
of tef varieties in the South and Southwest Ethiopian condition. The study used data collected for
only one season, which may limit the strength of its recommendation. However, the results are crucial
in directing the breeding decision following additional season evaluation of the varieties in the same
locations.
