Current status on coffee leaf rust (hemileia vastatrix) in sidama and gedeo zone, southern Ethiopia

Abstract

Coffee is the most important and second traded commodity next to oil in the world. In Ethiopia, coffee leaf rust caused by Hemileia vastatrix is one of the third most economically important diseases of Coffee Arabica. The current status of coffee leaf rust was intensively assessed and examined in 189 sample coffee farms from six districts across major coffee growing areas of the Southern Ethiopia. At each farm, ten randomly selected trees on a diagonal transect across the farm were assessed for disease incidence and severity. The survey data showed that coffee leaf rust was present in all assessed district varying in magnitude and extent of damage. The highest overall mean of rust incidence (38.6%) and severity (13.80%) was recorded at Dilla zuria while the lowest incidence (10.52%) and severity (1.38%) was at Yergachaffee district. The highest altitude range was obtained at Yergachaffee (1838-2056) while the lowest was at Dilla zuria (1434-1825) district. Overall mean severity and incidence result indicate that, there was statistical (p = 0.058 for severity, p = 0.044 for incidence) and negative correlation between intensity and altitude (severity, r= -0.80 and incidence, r= -0.82). The linear regression equation of severity and incidence obtained from the data was Y= -0.036X+73.16 and Y = -0.074X +158.9 (where Y= percentage CLR severity and incidence, respectively and X= altitude). This regression equation implies that, in higher elevation areas the rust intensity was low as compare to the lower elevation. Finally, the disease was remarkably increasing from time to time in all assessed coffee farms. Therefore, appropriate measurement like farmers’ awareness creation and training on how to control disease as well as appropriate agronomic managements has to be seriously undertaken. In addition, development of coffee leaf rust resistant varieties to southern Ethiopia through resistant breeding has to be set high priority.