@article{833, author = "Alemu Nega and Fikre Lemessa and Gezahegn Berecha", abstract = "Maize (Zea mays L.) is one of the most important food security crops mainly due to its high productivity and wider adaptability in Ethiopia. In recent years, grey leaf spot (GLS) has become a serious disease challenging maize production across the different parts of the country. Empirical study that evaluated the virulence variation of Cercospora zeae-maydis isolates and their reaction to maize varieties in Ethiopia is lacking. Therefore, this study was conducted to evaluate the virulence variation of four C. zeae-maydis isolates of different locations on six maize varieties under greenhouse conditions during 2015 cropping season. Data were recorded on latent period, lesion length, initial and final percent severity index (PSI), disease infection rate, area under disease progress curve (AUDPC) and dry biomass yield. Highly significant difference were observed among tested C. zeae-maydis isolates, varieties and their interaction on latent period, lesion length, initial and final GLS severity, disease infection rate and AUDPC. Isolate Huru-I had the shortest mean latent period (21 days), highest initial (45.3PSI) and final (81.3PSI) GLS severity, highest lesion length (3.3cm), fastest disease progress rate (0.0297disease day-1), highest AUDPC (2188.67%-day) and lowest dry biomass yield (0.08kg) on tested maize varieties as compared to the other isolates. Huru-I was found to be the most aggressive isolate followed by Bor-S. In conclusion, this study revealed an extensive virulence variation among the isolates as well as variable responses of maize varieties tested. Results could be useful for maize breeder and producers in order to effectively manage maize GLS in Ethiopia.", issn = "23483997", journal = "IJRAS", keywords = "AUDPC, Grey Leaf Spot, Latent Period, Lesion Length, Maize Disease", month = "January", number = "1", pages = "54-66", title = "{V}irulence of {F}our {C}ercospora {Z}eae-maydis {I}solates on {T}olerant and {S}usceptible {M}aize {V}arieties {U}nder {G}reenhouse {C}ondition", volume = "7", year = "2020", }