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

Margarodes.

PHOTO 282. Above-soil-surface abnormalities of margarodes are associated with weaker growth (shorter and thinner shoots with leaves that are smaller and pale in colour), as can be visually seen in this grapevine (Malmesbury area). In this specific instance soil analyses revealed the occurrence of cysts (ground pearls) in the proximity of the roots.

PHOTO 283. Typical of margarodes is the occurrence of round cysts (ground pearls) in the vicinity of affected grapevine roots, while the latter per se do not display any visually detectable abnormalities. The size of the cysts is slightly bigger than normal match heads.

184 • A Guide to Grapevine Abnormalities in South Africa