Evaluation and Selection of Ethiopian Bread Wheat Varieties Using Linear Mixed Model

Abstract

Ethiopia is a country with diverse agro ecological settings which make the yield of crop variety fluctuate and make selection of best variety difficult. Thisstudy was conducted to select best bread wheat variety, variety that has higher performance with relatively stable performance across varyingenvironments, by evaluating the varieties in terms their average performance and stability across the test environments. The yield and stability of theperformance of 17 bread wheat genotypes across 18 test environments was evaluated using linear mixed model. The yield performance of genotypes wasevaluated using different types of BLUPs. The stability of genotypes was evaluated using different methods under mixed model assumption. Genotypessuch as ETBW5798, ETBW5800 and ETBW5879 were generally identified to have higher average yield with relatively stable performance across the testenvironments whereas Digelu, ETBW5875 and ETBW5899 were generally found to have poor performance in terms of average yield and stability as well. Currently very efficient experimental designs for agricultural experiment such as IBD, and Lattice designs have been introduced and such designs are not suitable for analysis using the usual fixed effect model and are better fitted using linear mixed model. So, a future multi environmental trial study that uses such designs must use the linear mixed model.