Distribution and Importance of Maize Grey Leaf Spot (Cercospora Zeaemaydis Tehon and Daniels) in West Oromia, Ethiopia

Abstract

Maize (Zea mays) is one of the most widely cultivated crops in the world. It occupies an important position in the world economy serving as food, feed, and industrial grain crop. In Ethiopia, a major staple food and an average productivity is about 3.94 t ha^-1, which is below the world average of 5.78 tones ha^-1. A significant portion of this yield gap is attributable to biotic and abiotic stresses. Diseases play a major role among the biotic constraints. Of these, grey leaf spot (Cercospora zeae-maydis) is one of the major foliar diseases threatening maize production in Ethiopia. Also, in Ethiopia the loss caused due to GLS reached 49.5% and more when the pathogen attacked before the flowering stage. Therefore, the objective of this study was to assess the distribution and importance of Grey Leaf Spot. The field assessment was conducted during 2017 main cropping season by sampling 81 maize fields in 9 districts from 3 zones. The survey result showed the highest disease prevalence 62.96 % was recorded in East Wollega zone and the lowest (22.22%) in West-Wollega zone. The highest mean incidence 35.06 % was recorded in East Wollega zone whilst the lowest 9.51% in West-Shewa. The maximum disease Severity index of 31.43% was in East Wollega zone followed by West-Shewa having 11.98% and West-Wollega (10.05%) zones. At a district level, the highest prevalence was recorded in Leka-Dulecha followed by Gobu-Seyo with disease prevalence of 88.9% and 66.7%, respectively, whereas the minimum prevalence was at Ayra-Guliso Gimbi and Bako-Tibe, each with 22.2 % prevalence. The highest mean disease incidence 48.15% was recorded at Gobu-Seyo followed by Leka-Dulecha 47.77%, whereas the lowest was recorded in Gimbi 1.1% district. The highest mean disease severity index was recorded in Leka-Dulecha 46.11% followed by Gobu-Seyo 39.15%, whilst the lowest in Gimbi 1.78%. Thus, there is a need to develop management strategies like crop rotation with non-host, use of tolerance varieties to reduce the impact of GLS on maize production in the study area.

Keywords: Cercospora zeae mayds, Incidence, Severity Index

DOI: 10.7176/JNSR/13-15-01

Publication date:September 30^th 2022