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

Drowning.

PHOTO 419. In this instance specific canals with run-off water, in combination with insufficient drainage, affect terraced Sauvignon blanc grapevines in the Hout Bay area and may be considered a probable cause of leaf yellowing in reaction to drowning. It appears that soil and root examinations of individual grapevines, some of which have already died, revealed the absence of Phytophthora , inter alia, as a possible cause thereof.

PHOTO 420. Persistent, visually noticeable accumulation of water above the surface of the soil (which will eventually contribute to the grapevines’ dying) is usually an advantage in terms of the correct identification of drowning conditions.

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