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

Black foot (8); Petri disease (black goo) (9).

PHOTO 8. Black foot xylem discolouration is revealed by this longitudinal section through the foot of the rootstock.

PHOTO 9. Discolouration, blockage and “gumming” of xylem that may be ascribed to Petri disease (black goo).

A Guide to Grapevine Abnormalities in South Africa • 13