Tef is one of the main cereal crops and its injera is the major staple food for the majority of Ethiopians. Tef grain physical quality especially color is an important attribute influencing preference of consumers, the market prices and nutritional quality. However, the effect of the growing environment and the genotype on its physicochemical quality is not yet investigated. The study was, therefore, aimed at assessing the effects of genotypes (G) and growing environments (E) on physicochemical quality of tef grain. Ten diverse locations and nine tef genotypes were selected based on soil and climatic variability as well as variation in grain color [seven white and two brown). Most of tef grain physicochemical contents significantly (P ≤ 0.01) different between genotype, environment and G x E interaction effects. The environment, wherein tef was grown, accounted for the greatest proportion of variation in S (saturation), and V (brightness) values of the white grain genotypes (16.8%, 43.9%, and 66.8%) and G x E interaction effects (33.7%, and 24.5%) as compared to genotype alone (22.5%, and8.7%). Growing areas of greatest precipitation will reduce the brightness value of tef grain. Soil parameters such as soil pH, Ca, Mg, and P play a positive and negative roles in grain brightness and saturation values of tef, respectively. However, grain minerals had no influential role on the color of tef grain in this study. Tef growing areas tied to both climatic and edaphic factors are critical in governing both grain density and size. The role of genotype was more influential in the grain size of tef than the grain density. The raise of growing locations altitudes and precipitation increased tef grain density. The environment and genotype by environment interaction effects accounted a greater proportion of the variation of grain P, K, Ca, Mg, Na, S, Fe, Zn, B, Mn, Cu, and Mo minerals concentrations, while the genotype effect was relatively low. The variability of grain fiber, fat, protein, and starch compositions were also due to environment (70.0%, 46.9%, 70.9%, and 20.5%, respectively), and genotype by environment interaction (28.3%, 47.3, 27.5%, and 67.7%, respectively), while genotype played a minor role (1.7%. 5.8%, 1.6%, and 11.8%. respectively). With location by genotype interactions, there was no consistency in the dominance of any single genotype across all 10 locations in most of the tef grain mineral concentration and proximate compositions. The brown grain color genotype superiority in grain mineral and proximate composition is not supported by this research, rather the brown color genotypes were the lowest in grain starch concentration on the majority of the locations in this study. Generally, most physical and chemical quality variables of tef grain were markedly influenced by tef growing environments and their interactions with a minuscule role of genotype. Therefore, selection of suitable teff growing environments and proper soil pH and nutrient management would be so important for harnessing the maximum potentials of tef with the desired physicochemical quality of tef grain in Ethiopia.
