Avances en ciencia y tecnología de cultivos

Abstracto

Geographical Distribution, Incidence and Severity of Tef (Eragrostis tef) Diseases in Ethiopia

Ashenafi Gemechu Degete

Tef (Eragrostis tef) is the most important cereal in Ethiopia and is threatened by biotic and abiotic constraints. Among the biotic, tef leaf rust (Uromyces eragrostis), head smudge (Helmintosporium miyakei), smut spp and zonate eyespot (Hemintosporium gigantum) are among the major constraints of tef production. Information on the distribution of those diseases, occurrence and reaction of cultivars to those diseases in Ethiopia were not well known. Therefore, the aim of this survey was to observe the performance of commercial cultivars and understand the distribution of major tef diseases in the country. The survey was made in the 2020 and 2021 main cropping seasons following the main roads and accessible routes in each survey district. Five stops were made in each tef field by moving “X” fashion at each stop interval and data were collected from each. A total of 11 zones and 41 districts were covered during the survey. A total of 107 fields were surveyed and all the observed fields were infected by tef leaf rust disease and followed by head smudge. The prevalence of tef leaf rust was 100% and followed by head smudge having a mean value of 30.8% and the lowest prevalent disease was smut with a prevalence of 12.2%. The highest mean severity (38.8%) and incidence (100%) value of tef leaf rust was recorded in the East Gojam zone and followed by Silte zone with the mean value of tef leaf rust severity and incidence of 77.8 and 34.4%, respectively. The mean value of head smudge incidence and severity was 40 and 42% in the East Shoa zone followed by West Gojam with the mean incidence and severity values of 31.3 and 37.1% respectively. Of the assessed fields, the Magna variety was the most popular (35.5%) and followed by the Quncho variety which accounts for about 30.8% of area coverage. The severity of the diseases was increased because of improved agronomic practices (Row planting, informal seed system, late planting and cultivars) that are susceptible to disease become common and no chemical controls were practiced on those diseases so far. Currently, the tef leaf rust was becoming severe and using fungicide may be an option to control this disease. Evaluation of fungicides and selecting of effective ones against head smudge and smut disease will be the next work. Screening of germplasm to those diseases and selecting those tolerant lines and incorporating in the breeding program will also be another option to control those diseases in the future