A Survey of the Major Sorghum Production Regions for Foliar and Panicle Diseases during the 2022 Growing Season in Senegal, West Africa

Sorghum is a vital commodity and greatly contributes to the daily calorie needs for millions of the inhabitants in Senegal, West Africa. Yet, sorghum productivity and profitability are impacted by diseases. In the 2022 growing season, 122 farmers’ fields across 7 regions, notably Diourbel, Fatick, Kaffrine, Kaolack, Kolda, Tambacounda, and Thies were surveyed for foliar and panicle diseases. During the survey, stops were made at 30 km intervals and at each stop, 2 - 5 fields were evaluated. In each field, 40 plants mostly at soft to early hard dough stages of development were assessed using a W-shaped pattern to cover the whole field. A total of 13 diseases, including leaf blight, anthracnose, Zonate leaf spot, Sooty stripe, rough leaf spot, oval leaf spot, long smut, grain mold, and covered kernel smut were documented. The most predominant diseases were leaf blight, anthracnose, and zonate leaf spot. The prevalence of leaf blight was 100%, while anthracnose and zonate leaf spot were found in 93 out of the 122 fields surveyed, indicating a 76% prevalence, respectively. Across the regions, the prevalence of rough leaf spot was 47%, covered kernel smut (32%), oval leaf spot (19%) and target leaf spot (19%). Mean incidence of leaf blight was high in all regions, ranging from 94% (Kaolack) to 100% (Fatick and Tambacounda). The highest mean incidence of anthracnose (62%) and covered kernel smut (16%) was noted in Tambacounda region. In the region of Thies, the highest mean incidence of zonate leaf spot (49%) was recorded. The mean severity of leaf blight (37%) was highest on plants assessed in the region of Kaffrine, followed by those in the regions of Kaolack, Tambacounda, and Kolda. Anthracnose infection was most intense on plants evaluated in Kolda, while zonate leaf spot was most severe in the region of Tambacounda. Fields with incidences of 85% and above were considered as “hotspots” to evaluate sorghum germplasm for disease resistance. This survey is significant because the information obtained will be beneficial to plant pathologists, sorghum producers, government officials, and funding agencies to prioritize research projects that ensure productivity and food security.