Efficacy of fungicide against cercospora leaf spot (Cercospora sesami) disease of sesame (Sesamum indicum)

Abstract

Cercospora leaf spot (CLS) is a major constraint in sesame production due to its polycyclic nature and the pathogen’s tendency to develop resistance to single-site fungicides. This study evaluated the efficacy of Propiconazole, Metalaxyl, Tebuconazole, and Tetramethylthiuram disulfide (TMTD) applied alone and in combination for CLS management. Field experiments were conducted at Metema and Kokit, West Gondar, Ethiopia, during the 2023 and 2024 cropping seasons using RCB design with three replications. Treatments consisted of seed dressing and foliar sprays with an untreated control. A local variety Gondar deyo was planted. Data on disease severity, yield, and yield components were recorded. Combined analysis showed highly significant ( P  ≤ 0.0001) differences among treatments for disease severity, (AUDPC) and grain yield. combinations, particularly Tebuconazole + TMTD (AUDPC: 905.48%-day; yield: 836.09 kg ha⁻¹) and Metalaxyl + TMTD (AUDPC: 978.00%-day; yield: 793.89 kg ha⁻¹), achieved superior disease suppression and yield improvement. In contrast, single fungicides were less effective (AUDPC > 1390%-day), and the control recorded the highest disease severity (1543.70) and lowest yield (530.46 kg ha⁻¹). Overall, integrating systemic and protectant fungicides, especially Tebuconazole + TMTD, proved most effective for sustainable CLS management.