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

Esca dieback.

PHOTO 119. With regard to esca, internal rotting after initial infection continues unabated and eventually results in sudden dieback of the entire grapevine – or as in this particular instance, of specific shoots with bunches.

PHOTO 120. Gradual esca dieback in this Roobernet grapevine over a period of approximately 10 years. At this stage the only shoot growth occurred on the tip of the left cordon arm, while the right cordon arm has already died back totally. Although such phenomena may be confused with dead- arm disease, diagnostic tests revealed esca to be the true cause. Note that deformed leaves (as in the photo) may also be confused with damage by herbicides, inter alia.

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