First report of Clavibacter nebraskensis in South Africa
Clavibacter nebraskensis causes Goss’s wilt and leaf blight of maize (Zea mays). It is a(n) (re)emerging disease in the USA and has recently been reported from Mexico (EPPO RS 2024/137).
C. nebraskensis was detected in several localities in four provinces in South Africa. Samples were collected from maize farms in Parys (Free State Province), Fochville, Lichtenburg, Potchefstroom (North-West Province) and Carletonville (Gauteng Province) where testing was carried out using molecular techniques (PCR and sequencing). The presence of the bacterium was also reported in the Eastern Cape, through visual inspection on samples.
Surveys in other parts of the country are conducted where host plants are produced, and no further detections have occurred so far. Phytosanitary measures are being implemented in the affected farms. The Department of Agriculture, Land Reform and Rural Development is continuing with research to understand the epidemiology and management of the pest to support local maize producers while conducting delimiting surveys to determine the extent of the spread of the disease.
The pest status of Clavibacter nebraskensis in South Africa is officially declared as: Present: not widely distributed and under official control.
Sources
IPPC website. Official Pest Reports- South Africa (2025-01-14): Notification on the detection of Clavibacter michiganensis subsp. nebraskensis, Goss’ Wilt on maize, in the Republic of South Africa https://www.ippc.int/fr/countries/south-africa/pestreports/2025/01/notification-on-the-detection-of-clavibacter-michiganensis-subsp-nebraskensis-goss-wilt-on-maize-in-the-republic-of-south-africa/