Mekonen S., Alemu T., Kassa B., Forbes G.
Southern Agricultural Research Institute - SARI, Awassa Research Center, P.O. Box 06, Awassa, Ethiopia; Department of Plant and Horticultural Sciences, Hawassa University, P.O. Box 05, Awassa, Ethiopia; Ethiopian Agricultural Research Organization, Holetta Agricultural Research Center, P.O. Box 2003, Addis Ababa, Ethiopia; Centro Internacional de la Papa - CIP, Apartado 1558, Lima 12, Peru
Mekonen, S., Southern Agricultural Research Institute - SARI, Awassa Research Center, P.O. Box 06, Awassa, Ethiopia; Alemu, T., Department of Plant and Horticultural Sciences, Hawassa University, P.O. Box 05, Awassa, Ethiopia; Kassa, B., Ethiopian Agricultural Research Organization, Holetta Agricultural Research Center, P.O. Box 2003, Addis Ababa, Ethiopia; Forbes, G., Centro Internacional de la Papa - CIP, Apartado 1558, Lima 12, Peru
Late blight is an important disease of potato in Ethiopia, causing up to 100% loss in susceptible cultivars. In this study, two putatively resistant cultivars of relatively recent introduction (Jalenie and Gudenie) and a widely grown susceptible cultivar (White Flower) were evaluated for late blight severity and yield under five different contact fungicide (mancozeb) regimes and in unsprayed plots. Trials were carried out at two major potato production locations in southern Ethiopia: Awassa and Kokate, located at 1700 and 2156 meters above sea level, respectively. Greater disease pressure occurred at Awassa but the three cultivars performed consistently based on relative disease severity levels at the two locations. While White Flower was assigned a susceptibility score of 8 (highly susceptible) in both sites, Jalenie had scores between 1 and 0, and Gudenie had scores of 3 and 4, in Awassa and Kokate, respectively. With Jalenie, one application of contact fungicide was sufficient in both trials, while for Gudenie, two sprays appeared more appropriate as little or no gain was clear with three or more sprays. With the susceptible White Flower, four sprays were beneficial but little benefit was evident with the fifth spray. © the Brazilian Phytopathological Society.