Leaf elemental composition in a replicated hybrid grape progeny grown in distinct climates

Depuis 1973, une commission statutaire administre la législation qui régit le zonage vitivinicole en Afrique du Sud. La province «Le Cap de l’ouest» cerne toutes les zones viticoles sauf quatre unités. Pour la plupart, le Cap de l’ouest a un climat méditerranéen. Les zones viticoles – qui produisent les «vins d’origine» – sont des régions, des districts, des quartiers et des domaines. Les régions sont vastes, séparées par la topographie, par ex. des chaînes de montagnes et des fleuves. Généralement, chaque région représente une zone climatique. Le climat de chaque district est plus homogène. Les quartiers sont exactement délimités par le climat, la topographie et la géologie. Les domaines sont les plus petits. Chaque domaine doit avoir un seul propriétaire.

Botrytis cinerea, a fungal pathogen commonly known as grey mold, which under specific climatic conditions can develop into a desirable form known as noble rot. In this process the fungus penetrates the grape skin, allowing water evaporation and concentration of sugars and flavors, while profoundly affects the metabolite composition of grapes, leading to the production of unique and desirable compounds in the resulting wines. The result is a unique and complex wine with a luscious sweetness, heightened aromatics, and a distinct character.

Drought and heat stress will pose challenges for the future of viticulture and wine quality, as grapevine biological processes are pushed beyond their optimum conditions. Efforts are increasing to study and predict the effects of drought spells and heatwaves on grapevine physiology and resulting harvest quality. This calls for the development of adequate systems to induce and manipulate the required stress, especially in open field trials where conditions are more difficult to control. We present a semi-controlled system for studying drought and heat stress in grapevine in the field.

The aim of this work was to study the trapping capacity of four polyaniline polymers towards phenolic compounds in wine-like model solutions. METHODS: The model wine solution was composed of 12% (v/v) and 4 g/L of tartaric acid adjusted to pH = 3.6. A series of centrifuge tubes (15 mL) were filled with 10 mL of model solution enriched with 50 mg/L of five phenolic compounds (i.e., Gallic acid, caffeic acid, (+)-catechin, (-)-epicatechin, and rutin), and treated with different doses of PANI polymer (i.e., 0, 2, 4 and 8 g/L). After the addition of the polymer, the samples were stirred using a platform shaker at room temperature (20 ºC) for 2, 8, 16 and 24 h. All treatments included three replications.

New grape varieties with several resistance loci towards powdery and downy mildew allows to significantly reduce the use of fungicides