Identification, Incidence, and Prevalence of Foliar Diseases of Sorghum in Farmers’ Fields of the Tanout Commune in the Zinder Region, Niger

Abstract

Sorghum plays an important role in the rural economy of Niger. However, the production of this cereal is hampered by multiple pressures, including fungal diseases. The objective of this study is twofold: first, to identify foliar diseases of sorghum in the fields of farmers in the commune of Tanout, and second, to determine the incidence and prevalence of these diseases. The study was carried out in the commune of Tanout during the winter season from June to September 2025. One hundred (100) fields belonging to sorghum producers in 20 villages of the commune were surveyed, with five (5) fields per village. In each field, five (5) elementary plots, each composed of twelve (12) planting holes, were marked out for the identification and assessment of the prevalence and incidence of sorghum foliar diseases. Six (6) foliar diseases were identified: anthracnose, leaf blight, oval leaf spot, grey spot, zoned leaf spot, and sand grain disease. Out of a total of 6,000 sorghum hills examined, 3,839 hills showed symptoms of anthracnose, representing an average incidence of 63.98%; 3,088 hills showed symptoms of oval leaf spot, representing 51.47%; 2,039 hills showed symptoms of leaf blight, representing an average incidence of 33.98%; and only 94 hills showed symptoms of zoned leaf spot, representing an average incidence of 1.57% in the commune of Tanout. The prevalence of these diseases fluctuates in line with their incidence. The prevalence is respectively 97.6% for anthracnose, 87.2% for oval leaf spot, 82.6% for leaf blight and 13.4% for zoned leaf spot. The study revealed that anthracnose and oval leaf spots are the most widespread in the fields of farmers in the commune of Tanout with average incidence rates of 63.98% and average prevalence of 97.6% for anthracnose, and 51.47% incidence and 87.20% prevalence for oval leaf spots.