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

Crown gall.

PHOTO 155. A typical example of grotesque gall formation including the transformation of initially creamy-white galls into dark-coloured wart-like structures.

PHOTO 156. Gall formation on a cordon arm (nearest the main trunk). Note the hard, dark-coloured and wart-like structure with clear signs of parts that have already fallen off.

A Guide to Grapevine Abnormalities in South Africa • 105