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

High nitrogen levels (464); toxicities (465).

PHOTO 464. Intense, dark green leaf discolourations are induced by high nitrogen levels. Also note the early berry shattering, as seen in the 17:00 position.

PHOTO 465. In severe instances nitrogen toxicities (as in Photo 464) are associated with shiny blemishes on leaf surfaces, whereafter leaf edges are subject to browning and withering. Note that in addition to wind damage; erinose and downy mildew (on the leaf in the 15:00 position) can also be seen in this example.

A Guide to Grapevine Abnormalities in South Africa • 299