Abstract:
Leaf blades of three grapevine cultivars (Barbera, Croatina and Malvasia di Candia aromatica) were sampled at fruit set, veraison and harvest in 1988–1990 in 24 vineyards representative of the four pedoclimatic conditions (landscape forms, soil properties and Winkler bioclimatic index values) and of the two most common slope orientations in Val Tidone, a viticultural district in northern Italy.
Grapevine cultivars showed different nutrient concentration throughout the season, especially for K, Ca and Mg.
The year effect was predominant only for leaf N at fruit set, for P at harvest and for B at veraison and harvest.
K and Ca concentrations were strongly influenced by cultivar x year interactions.
N, P, K, Mg and Ca concentrations were strongly affected by environmental properties (soil type, altitude and mesoclimate of the site) whose effects could not be disaggregated.
N, P and K nutritional status were not affected by cultivar x environment interactions: cultivars responded in different manner, in terms of concentrations of Ca, B and Mg to the different soils and site mesoclimates.
Vineyard exposure played a significant role on leaf B at harvest: North-exposed plots had the highest B concentrations. Cultivar x exposure interaction affected leaf N, K and Ca.
Leaf diagnosis proved to be very useful to determine the effects of environmental factors on grapevine nutrition.
The diagnosis of leaf nutritional
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