Distribution and Importance of Maize Grey Leaf Spot in West Oromia, Ethiopia

Abstract

Maize (Zea mays) is one of the most widely cultivated crops in the world. In Ethiopia, it’s a major staple food with an average productivity of 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 attributed to biotic and abiotic stresses.  Of diseases, grey leaf spot is one of the major foliar diseases threatening maize production in Ethiopia. Loss caused due to grey leaf spot reached 49.5% in Ethiopia. The objective was to assess the distribution and importance of Grey Leaf Spot. The assessments were done by sampling 81 maize fields in 9 districts from 3 zones during 2017. Purposive multistage sampling method was used. Data were analyzed using three-stage nested design. The survey result showed the highest disease prevalence 62.96 % was recorded in East Wollega and the lowest (22.22%) in West-Wollega zone. The highest mean incidence 35.06 % was recorded in East Wollega whilst the lowest 9.51% in West-Shewa. The maximum Severity index of 31.43% was in East Wollega whereas the minimum in 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. The highest mean incidence 48.15% was at Gobu-Seyo whereas the lowest was recorded in Gimbi 1.1%. The highest mean severity index was in Leka-Dulecha 46.11% whilst the lowest in Gimbi 1.78%. Thus, there is a need to develop management strategies like crop rotation with non-host, use of tolerant varieties to reduce the impact of the disease on maize production.

Keywords: Maize disease, Incidence, Severity Index

DOI: 10.7176/JNSR/11-17-03

Publication date:September 30^th 2020