Wheat stem rust (black rust) is one of the most important airborne diseases of wheat (Triticum aestivum) caused by Puccinia graminis f. sp. tritici remains a constraint to the world’s wheat production. Because of the sudden changes in stem rust race patterns, commercial varieties tend to become vulnerable globally at large and particularly in Ethiopia. It was responsible to cause 6.2 million metric tonnes per year or higher losses under severe epidemics at global level. Therefore, this study was initiated to assess information on the current distribution of wheat stem rust in the study area. Purposive multi-stage sampling procedure was used to select major wheat growing zones, districts and peasant associations. Assessment was carried out on 95 wheat farms in 7 districts across the three zones of Tigray region. The results of the study showed that wheat stem rust was 70.53% prevalent across the study areas with significantly (p < 0.01) varied incidence and severity damage among fields, districts, and zones. The mean prevalence of stem rust was 85.55% in Southern, 62.22% in Eastern and 53.33% in Southeast zones. The highest disease incidence of 78.67, 66.5, and 47.33% were recorded in Kilte Awulaelo, Raya Azebo, and Ofla districts, with corresponding severity of 43.67, 35, and 21.93%, respectively. The overall mean incidence and severity of stem rust was 41.84 and 21.36% respectively, which is higher than the previous reports from the region indicated an increase in its distribution and intensity. Therefore, there is a need to develop a coordinated network on the wheat stem rust assessment program for virulence and/or avirulence updated information in the region.

Keywords: Incidence, Prevalence, Puccinia graminis f.sp. tritici, Severity, Stem rust, Wheat