A Guide to Grapevine Abnormalities in South Africa - P.G. GOUSSARD

Oidium.

PHOTO 12. The characteristic white powdery fungal growth associated with oidium is established and rapidly distributed to cover entire leaf surfaces.

PHOTO 13. A typical example where control measures against oidium were not sustained during the post-harvest period. In addition to oidium, leafroll is another factor which hampers normal physiological processes in these leaves.

18 • A Guide to Grapevine Abnormalities in South Africa