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

Zinc deficiency (476); manganese deficiency (477).

PHOTO 476. Initially zinc deficiencies are associated with the onset of visually detectable chlorosis to apical leaves, whereafter leaves assume a consistently smaller format with enlarged petiole sinuses.

PHOTO 477. Characteristic of manganese deficiencies is the onset of a pale, interveinal chlorosis between the primary and secondary veins in older leaves, whereas the areas around the finer veins tend to remain green.

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