Pacific Northwest wine regions and climates

Over the past few decades, viticultural research has made numerous contributions which have made it possible to better understand the behavior of the vine as well as its response to the conditions imposed on it by the environment and agronomic practices. However, these results have only rarely been used in the practical management of vineyards because the research has been carried out using partial experimental models where reality is only represented by a few factors which are sometimes even made more complex by the introduction of elements foreign to the existing situation and difficult to apply to production (varieties, methods of cultivation, management techniques, etc.). To these reasons, one could add a low popularization of the results obtained, as well as the difficulty of implementing the scientific contributions, which does not allow the different production systems to fully express their potential. This limit of viticultural research can only be exceeded by the design of integrated projects designed directly on and for the territory. Indeed, only the integrated evaluation of a viticultural agro-system, which can be achieved through zoning, makes it possible to measure, or even attribute to each element of the system, the weight it exerts on the quality of the wine.

Nitrogen (N) nutrition of the vineyard plays a crucial role in the composition of must and wine, impacting fermentation, as well as the aroma and taste of the final product. N-deficient grape juice can result in increased astringency and bitterness, and a decrease in pleasant aromas in the wine.

Grape postharvest dehydration is a widely used technique for the special wines production, where genetic features, ripeness degree and environmental factors strongly influence the metabolic processes [1].

Grapevine trunk diseases including Eutypa dieback are a major factor in the decline of vineyards and may lead to loss of productivity, reduced income, and premature reworking or replanting. Several studies have yielded results indicating that vines may be more likely to express symptoms of vascular disease if their health is already compromised by stress. In Australia and many other wine-growing regions it is a common practice for canes to be wrapped tightly around the cordon wire during the establishment of permanent cordon arms. It is likely that this practice may have a negative effect on health and longevity, as older cordons that have been trained in this manner often display signs of decay and dieback, with the wire often visibly embedded within the wood of the cordon. It is possible that adopting a training method which avoids constriction of the vasculature of the cordon may help to limit the onset of vascular disease symptom expression. A survey was conducted during the spring of two consecutive growing seasons on vineyards in South Australia displaying symptoms of Eutypa lata infection when symptomless shoots were 50–100 cm long. Vines were assessed as follows: (i) the proportion of cordon exhibiting dieback was rated using a 0–100% scale; (ii) the proportion of canopy exhibiting foliar symptoms of Eutypa dieback was rated using a 0–100% scale; (iii) the severity of strangulation was rated using a 0–4 point scale. Images were also taken of each vine for the purpose of measuring plant area index (PAI) using the VitiCanopy App. The goal of the survey was to determine if and to what extent any correlation exists between severity of strangulation and cordon dieback, in addition to Eutypa dieback foliar symptom expression.

Les profils climatiques appropriés pour une activité photosynthétique optimale de la vigne sont déterminés dans différentes régions d’Afrique du Sud et localités à l’intérieur d’une région particulière.