Tef is the only cereal cultivated for human consumption in the genus Eragrostis.Compared to other cereal crops tef is resilient and able to withstand adverse weather conditions. The major problems for adaptation of tef are lack of diversified alternative improved varieties adapted to the study area and limited availability of varieties. This study was carried out to recommend best adapted and high yielder tef varieties in the study area. A total of twelve released tef varieties were used in the experiment. Randomized Complete Block Design (RCBD) with three replications was used to execute this research activity. The analysis of variance showed that the genotypes differed significantly (p< 0.05) for harvest index, and lodging, and were highly significant (p<0.001) for days to heading, plant height and panicle length. Heritability estimate was moderately high for panicle length followed by plant height and days to 50% heading. Panicle length and plant height showed moderately high heritability with a high genetic advance as a percent of the mean. Grain yield showed a positive and highly significant (P < 0.001) correlation with biomass yield (0.97), lodging index (0.84) and plant height (0.82). To alleviate the limited access of improved tef varieties to study area these selected varieties need to be demonstration and popularized to farmers with their full production package to enhance the productivity of tef crop.

Cotton varieties that are high yielding and resistant to pests are required to improve production and productivity and to capitalize on the crop’s enormous potential and its critical role in Ethiopia’s expanding textile industry. Lack of improved cotton technology has forced farmers to recycle local varieties for ages which have become very susceptible to pests which are the major causes of very low productivity and quality of cotton in the country. Among major pests, bollworms (Helicoverpa armigera and Pectinophora gossypiella) account for 36–60% of yield losses. In the absence of genetically resistant or tolerant varieties, genetically engineered bollworm-resistant Bacillus thuringiensis (Bt) cotton has offered a great opportunity to reduce crop losses from bollworms. The objective of the study was to evaluate the efficacy of bollworm resistance and adaptability of Bt cotton varieties across cotton growing environments in Ethiopia and provide recommendations. Two Bt cotton hybrids (JKCH 1947 and JKCH 1050), one Bt OPV (Sudan), and three OPV conventional varieties (Weyito 07, Stam-59A, and Deltapine-90) were evaluated at seven different agro-ecologies using a randomized complete block design (RCBD) with three replications. Results showed significant differences among genotypes for yield and other traits. Hybrids JKCH 1947 and JKCH 1050 were the top high yielders under high and mild bollworm infestations, with mean seed cotton yield of 3.10 t·ha−1 each and lint yield of 1.20 and 1.19 t·ha−1, respectively, whereas the standard check Deltapine-90 (popular variety) recorded a mean seed cotton and lint yield of 2.3 t·ha−1 and 0.8 t·ha−1, respectively. Combined analysis showed that genotypes, environment, and the genotypes × environment interactions had a highly significant effect ( P  < 0.05) on fiber quality. Weyito 07 and the two hybrids (JKCH 1947 and JKCH 1050) had upper half mean fiber lengths in the range of 27.78 to 32.11 mm. For fiber strength, genotypes Weyito 07, JKCH 1050, Stam-59A, and JKCH 1947 had 33.50 g/tex, 28.59 g/tex, 28.00 g/tex, and 27.75 g/tex, respectively. The fiber quality values of the hybrids were within acceptable limits, with staple lengths ranging from 27.78 to 28.44 mm and fiber strengths ranging from 27.75 to 28.59 g/tex. Results show potential adaptation of the hybrids under different cotton growing environments and their superior yield performance due also to added protection of yield losses from damage by bollworms. The contrast is bigger under high insect pressure conditions due to the genetically engineered Bt trait compared to the conventional varieties. The effective field resistance against bollworms in most locations shows that wider use of these hybrids can enhance cotton productivity and quality in Ethiopia.