The average incidence (53.85, 66.5, and 30.33 %), severity (33.9, 33.37 and 7.5 %), and prevalence (74.07, 95.0, and 55.17 %) of potato late blight were scored in Meket, Wadla, and Angot districts respectively. The survey result revealed 48.20 % incidence, 23.68 % severity and 72.36 % prevalence of the disease in the study area. A field survey was conducted in North Wollo Administration Zone of the three districts (Meket, Wadla, and Angot) to assess status of the potato late blight disease and find out the effect of different cropping practices adopted in the study area on late blight disease incidence and severity. Aster Yellows phytoplasma can be transmitted from plant to plant through grafting and by insects called leafhoppers, but not by touching.Phytophthora infestans causing late blight is the major problem of potato production in Ethiopia. Phytoplasmas, like bacteria, are prokaryotes (have no nucleus), but lack cell walls and are difficult to culture in laboratories. Parra, entitled, "PCR amplification of the Irish potato famine pathogen from historic specimens", reported in Nature Volume 411 on page 695.Īster Yellows is a disease caused by a phytoplasma. Previously, most plant pathologists had believed that US-1 was a direct descendant of the fungus that caused the Irish potato famine.įor additional information, see the report authored by J.B. Furthermore, by using specific fragments (pieces) of the DNA from these samples, the authors suggest that the US-1 clonal lineage of the fungus which dominated the population of the fungus world wide before the 1980's was not solely responsible for the epidemics during the Irish famine and later in the epidemics in the 19th and 20th centuries. The authors not only were able to isolate the DNA from samples collected in 18 but used that DNA to confirm that the agent responsible for the epidemics during that time was in fact P. Parra, examined these musty old herbarium collections using modern DNA technologies in an effort to confirm the identity of the pathogen and its relationship to genotypes now found in the world. Recently, three scientists at North Carolina State University, J. Phytophthora infestans also infects potato tubers causing rot and complete loss of the tuber. The most severely infected plants are killed by infection. Potato plots showing different levels of destruction by Phytophthora infestans. The earliest collections are from 18 coinciding with the Irish famine. These samples were carefully preserved in herbariums. During the nineteenth and early twentieth centuries scientists had collected samples of infected potato and tomato plants all over the world. The new strains were resistant to previously effective fungicides which were consequently no longer effective. The disease made headlines in the US much more recently when new strains of this fungus caused epidemics in the US which were very difficult to bring under control. The white areas are areas on which the fungus is sporulating. Lesions of late blight on leaves and stems of potato. Many families in the US emigrated to the US during the years in which this famine was at its peak. It also caused severe epidemics in Great Britain, Holland and Belgium during the same years it caused the Irish potato famine. Late blight is often noted as being responsible for the Irish potato famine in 1845. Late blight of potato, caused by a fungus called Phytophthora infestans, remains to this day a very serious disease that can cost potato growers attempting to control its presence many thousands of dollars each season. Lesions of late blight caused by Phytophthora infestans on potato leaves.
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