Status and Relative Distribution of Maize Streak Virus in Western Ethiopia

Abstract

Maize production in Ethiopia is constrained by both biotic and abiotic factors, and diseases of maize caused by viruses are serious threats to maize  production. Maize streak (MS) is one of the most severe and widespread diseases that adversely reduces maize production. Hence, this study was  conducted to assess the status and distribution of maize streak and to diagnose Maize streak Virus isolates. Surveys were conducted during the  2019 main cropping season in different agro ecological zones of Gambela, Benishangul-Gumez and Oromia regions. Maize and grasses in maize  fields with suggestive MS-like symptoms were sampled for laboratory testing. Out of 127 maize fields visited, based on MS-like symptoms, the  disease was prevalent in 100 (79%) fields assessed, from which 100 maize and 5 grass samples were collected for laboratory testing. High  prevalence, incidence and severity of MS were recorded at low altitude areas; whereas low incidence and severity were recorded at high altitude  maize growing areas. The mean incidences of 64%, 59% and 33%; and severities of 4.3, 4 and 3 (on 1-5 scoring scale) were, respectively, recorded in  Gambela, Benshngul-gumeze and Oromia regions. Results of laboratory testing employing PCR showed that out of 100 symptomatic maize and 5  grass samples analyzed, MSV was recovered from 95 (90%) maize and none of the grass samples. Based on the results of the present study, MS is an  economic disease of maize at low and mid altitude growing areas. Hence, disease management options involving development and deployment  of resistant vanities along with cultural practices should be sought.