Some common grapevine diseases in South Africa

In this article, Janine Ryan looks at the symptoms, treatment and prevention of some of South Africa's most common fungal, bacterial and viral diseases of grapevines.

-  Janine Ryan

Like grapes grown in any other region, South African grapes can be susceptible to certain diseases. However, it's important to note that the prevalence and severity of diseases can vary depending on factors such as climate, grape varieties grown, farming practices, and disease management strategies implemented by growers.

South Africa has a diverse climate, ranging from Mediterranean in the Western Cape to subtropical in certain regions, which can create different disease pressures. In some areas, such as the Cape Winelands, the conditions are well suited to grape cultivation, with dry summers and low humidity, which can help reduce the incidence of certain fungal diseases.

However, certain grape diseases, including downy mildew and powdery mildew, can still pose challenges, particularly in regions where cool, wet conditions prevail during the growing season. Botrytis bunch rot can be a concern in areas with higher humidity, which can promote the development and spread of the fungus.

Despite these challenges, the industry's commitment to research, innovation and best practice mitigates the risks and helps to maintain a competitive grape sector.

FUNGAL DISEASES DOWNY MILDEW

Downy mildew (Plasmopara viticola) can cause significant damage to grapevines. According to the Michigan State University: Integrated Pest Management (MSU), downy mildew is widespread. The fungus thrives in cool, humid conditions. The spores are wind-borne.