study of genotype ×environment interaction for sugar beet monogerm cultivars using ammi method

in order to study the effect of genotype × environment interaction and stability of sugar beet varieties, four cultivars, including shirine, zarghan, laetitia and 7112 hybrid were planted in five major areas near to sugar beet factory of biseton as kangavar, sahneh, chamchamal, dinavar and ravansar for three years (2006-2008) using a randomized complete block designs, with three replications. analysis of variance for root yield, sugar yield and sugar content showed that the environment and genotype main effects and genotype × environment interaction were significant. ammi model with the first two principal components explanied most of the genotype × environment interaction (99.9%, 99.3 % and 99.4 %) for root yield, sugar yield and sugar content, respectively. laetitia was the best genotype based on the biplots, but had the least general adaptation to the environments and showed specific adaptation to sahneh location. zarghan  had the most highest general adaptation to the locations, but had the average value for the traits studied.  7112 hybrid had the specific adaptation to kangavar location. among the locations, sahneh was the best location, and was more similar to chamchamal. based on means and the first two interaction components, dinavar was the poorest location. therefore, sahneh and ravansar are recommended as suitable places for planting of sugar beet and laetitia is suggested as the best genotype for these locations.