The influences of interaction of a height above sea level and land inclination on the growth and yield of Vitis vinifera L. cv. 'Merlot' in Goriška Brda winegrowing region

Abstract

Modern viticulture requires collecting data of the factors, which have an important influence on the grapevine growth, fertility and yield quality. A terroir is determined by several ecological factors, among which a height above sea level and land inclination play an important role. Both factors change the local mezo and microclimate regime of the absolute winegrowing sites and they are both directly connected with the quantity and the duration of solar radiation. The parameters of grape quality, such as soluble sugars, the total acidity and the content of polyphenols and anthocyanins, demonstrate which winegrowing sites are suitable for growing the grapevine. The land inclination and above sea level have the influence on the time of the bud-burst, flowering and verasion. Winegrowers should therefore perform the grape harvest earlier in case of the optimum yield per a grapevine on ‘terasse’ vineyards, as the concentration of colouring substances with red cultivars decreases at the stage of technical maturity. The interaction of both factors does not have a direct influence on the grape quantity and quality. Despite the change of land inclination, the height above sea level in the Goriška brda winegrowing region does not alter considerably so as to strongly influence the parameters of growth and yield of Vitis vinifera L. cv. 'Merlot'. Winegrowers should adapt the vineyard management to the local mezoclimate regime and to the need of the individual type of grapevine.