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

PART 8

A lthough grapevines, in contrast with most other field and horticultural crops, show relatively low nutritional requirements, optimal in-vineyard performance – including sustainable quality and quantity standards – are based on providing continuous accessibilty to essential macro- and micro- nutrients, to ensure effective uptake/utilisation thereof – in the actual required and balanced amounts. Despite the fact that correct/meaningful fertilisation strategies are normally strived for in line with scientifically based guidelines, the occurrence of abnormalities as associated with either deficiencies or excesses of specific nutrients, are by no means unknown, and as such they are therefore singled out as recognised problem situations in the local and foreign wine and table grape industries. As considerable economic damage/losses may be suffered in cases of serious excesses or deficiencies, it is here also important to remain abreast of identification procedures in this regard. In addition, based on confusion with many other and even divergent causes, obtaining expert advice is srongly advised, in order to identify real tendencies with the aid of leaf and/or soil analysis. DEFICIENCIES AND TOXICITY OF NUTRITIONAL ELEMENTS 8

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