The most essential biotic stress factors limiting wheat production in the Thrace region (Turkey) for wheat production are the presence of leaf rust (Puccinia triticina) and yellow rust (Puccinia striiformis f.sp. tritici). Improve resistant genotypes and the use of genetic resistance is very essential to control the leaf and yellow rust diseases. The extent of damage mainly depends on climate factors crop stage, disease severity and cultivar susceptibility. The aim of the research was to evaluate advanced bread wheat genotypes for adult plant reactions for leaf rust (LR) and stripe rust (SR) under rainfed conditions. This experiment carried out with 25 advanced bread wheat genotypes across three environments (E1: Burgaz, E2: Tekirdağ and E3: Keşan) in the 2018-2019 cycles, in Trakia region, Turkey. The severity and the response rating were scored for adult plant field reaction using the modified Cobb scale during flowering period (Z60-69). The research was carried out in different locations under rainfed conditions and it was determined that there were significant differences in the infection rate especially in sensitive genotypes according to the locations. Coefficients of infections were calculated and values below 20 were considered to be tolerant. In the study, 12 (48%) and 11 (44%) genotypes were tolerant to leaf rust and stripe rust, respectively. The genotypes G11 (cv Aldane), G16 (cv Yüksel) and G19 (cv Abide) displayed zero disease severity to leaf rust. There was no infection of stripe rust in genotypes G16 (cv Yüksel), G17 (cv Damla) and G18 (cv Anafarta). There were differences in the infection coefficient between the locations with the effect of environmental factors. The infection coefficient was higher in LR than in SR across three environments. In leaf rust, while the highest infection coefficient was found in E1 (R2=0.33), the lowest coefficient was determined in E2 (R2=0.16). In stripe rust, the infection coefficients were very low in three environments. It was assumed that the difference in the infection coefficients was due to the difference in climatic values such as precipitation, humidity and temperature, which were effective in the epidemic of LR and SR. In addition, research has shown the importance of the effect of the environment in the epidemic of biotic stress factors.
