Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes ...Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes and the relative importance of different stability parameters for improving selection in faba bean. The study was conducted using a randomized complete block design with four replications. G × E interaction and yield stability were estimated using 17 different stability parameters. Pooled analysis of variance for grain yield showed that the main effects of both genotypes and environments, and the interaction effect, were highly significant(P ≤ 0.001) and(P ≤ 0.01), respectively. The environment main effect accounted for 89.27% of the total yield variation, whereas genotype and G × E interaction effects accounted for 2.12% and 3.31%, respectively.Genotypic superiority index(Pi) and FT3 were found to be very informative for selecting both high-yielding and stable faba bean genotypes. Twelve of the 17 stability parameters,including CVi, RS, α, λ, S2 di, bi, S(2)i, Wi, σ2i, EV, P59, and ASV, were influenced simultaneously by both yield and stability. They should accordingly be used as complementary criteria to select genotypes with high yield and stability. Although none of the varieties showed consistently superior performance across all environments, the genotype EK 01024-1-2ranked in the top third of the test entries in 61.5% of the test environments and was identified as the most stable genotype, with type I stability. EK 01024-1-2 also showed a17.0% seed size advantage over the standard varieties and was released as a new variety in2013 for wide production and named "Gora". Different stability parameters explained genotypic performance differently, irrespective of yield performance. It was accordingly concluded that assessment of G × E interaction and yield stability should not be based on a single or a few stability parameters but rather on a combination of stability parameters.展开更多
A numerical method is developed to evaluate the dynamic stability parameters of aircraft. This method is based on the aerodynamic model proposed by Etkin. His model is analyzed and generalized. After giving the specif...A numerical method is developed to evaluate the dynamic stability parameters of aircraft. This method is based on the aerodynamic model proposed by Etkin. His model is analyzed and generalized. After giving the specific forms of the aerodynamic model, the dynamic stability parameters are determined by the unsteady flow field computation and a parameter identification technique. Numerical experiments show that this method is accurate in predicting the dynamic stability characteristics of blunt cones in hypersonic flight. 展开更多
基金supported by the Ethiopian Institute of Agricultural Research
文摘Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes and the relative importance of different stability parameters for improving selection in faba bean. The study was conducted using a randomized complete block design with four replications. G × E interaction and yield stability were estimated using 17 different stability parameters. Pooled analysis of variance for grain yield showed that the main effects of both genotypes and environments, and the interaction effect, were highly significant(P ≤ 0.001) and(P ≤ 0.01), respectively. The environment main effect accounted for 89.27% of the total yield variation, whereas genotype and G × E interaction effects accounted for 2.12% and 3.31%, respectively.Genotypic superiority index(Pi) and FT3 were found to be very informative for selecting both high-yielding and stable faba bean genotypes. Twelve of the 17 stability parameters,including CVi, RS, α, λ, S2 di, bi, S(2)i, Wi, σ2i, EV, P59, and ASV, were influenced simultaneously by both yield and stability. They should accordingly be used as complementary criteria to select genotypes with high yield and stability. Although none of the varieties showed consistently superior performance across all environments, the genotype EK 01024-1-2ranked in the top third of the test entries in 61.5% of the test environments and was identified as the most stable genotype, with type I stability. EK 01024-1-2 also showed a17.0% seed size advantage over the standard varieties and was released as a new variety in2013 for wide production and named "Gora". Different stability parameters explained genotypic performance differently, irrespective of yield performance. It was accordingly concluded that assessment of G × E interaction and yield stability should not be based on a single or a few stability parameters but rather on a combination of stability parameters.
文摘A numerical method is developed to evaluate the dynamic stability parameters of aircraft. This method is based on the aerodynamic model proposed by Etkin. His model is analyzed and generalized. After giving the specific forms of the aerodynamic model, the dynamic stability parameters are determined by the unsteady flow field computation and a parameter identification technique. Numerical experiments show that this method is accurate in predicting the dynamic stability characteristics of blunt cones in hypersonic flight.
