Screening of Finger Millet Genotypes for Resistance to Magnaporthe grisea in Northwestern Ethiopia

Abstract

Finger millet is one of the staple food cereal crops cultivated in Ethiopia. However, its production faces challenges due to blast disease. This study aims to screen resistant finger millet genotypes to blast disease under natural epiphytotic conditions, and to assess the yield potential of these resistant genotypes during the main cropping seasons of 2022, and 2023. A total of 64 finger millet genotypes, including both standard and local checks, were tested using a square lattice design with two replications at the experimental sites of Adet, and Finote Selam. The disease was scored starting from the initial incidence using a disease rating scale of 0-9 for leaves and 0-5 for necks, and heads, respectively. Among the genotypes evaluated in 2022 at Adet, 13 (20.31%) were classified as resistant, four (6.25%) as moderately resistant, 17 (26.56%) as moderately susceptible, and 30 (48.88%) as susceptible. In 2023, there were 14 (21.88%) resistant, 11 (17.19%) moderately resistant, 24 (37.50%) moderately susceptible, and 15 (23.44%) susceptible. At Finote Selam, the assessment in 2022 revealed three (4.69%) moderately resistant, seven (10.94%) moderately susceptible, 32 (50.00%) susceptible, and 22 (34.38%) highly susceptible genotypes, while in 2023, two (3.13%) were moderately resistant, six (9.38%) moderately susceptible, 38 (59.38%) susceptible, and 18 (28.13%) highly susceptible. The variations of genotypes in disease response across different locations, and years can be attributed to different ecological factors. Additionally, genotypes such as G7 and G20 were identified as high yielders but susceptible to blast disease. It would be beneficial to breed these with low-yielder genotypes like G13 and G61, which exhibit low terminal severity. Using of resistant, and moderately resistant genotypes in planting, and breeding programs can improve production by alleviating the impacts of blast and can reduce farmers dependency on chemical fungicides, which can reduce production costs and environmental impact.