Viticulture and climate: from global to local

Downy mildew is one of the most important grapevine diseases, caused by the Oomycete Plasmopara viticola. The management of the disease in organic agriculture can require up to 15 copper applications per year. However, copper accumulates in the soil, is phytotoxic and is toxic for organisms living in the soil, its use has been restricted in European Union to maximum 28 kg in 7 years. Therefore, testing of alternatives with equal effectiveness is desirable. Among those, the natural biopolymer chitosan, obtained from crab shells, proved to be effective toward downy mildew in plot experiments. The aim of our trials was to extend chitosan applications in large scale experiments in different years, cultivars and environmental conditions.

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

Dans le cadre d’une étude globale de l’influence du type de sol et de la conduite du verger sur la composition des pommes à cidre, une attention particulière est portée sur les facteurs amonts de la qualité comme

The spotted lanternfly (SLF; Lycorma delicatula) is a phloem-feeding polyphagous insect invasive to the Eastern U.S.. Since its first detection in Pennsylvania (U.S.) in 2014, large infestations and economic damage (e.g., decreased yield, vine decline, greater pesticide use) have been reported in an increasing number of vineyards, threatening the sustainability and growth of the wine industry in infested regions. Our team has been investigating the impacts of SLF phloem-feeding on physiological processes, fruit production, juice, and wine composition of different grape cultivars, and also evaluated if the SLF can transmit important grapevine pathogens. In addition, we are working closely with stakeholders to better enumerate the economic damage caused by this pest. These findings will provide relevant information to grape and wine producers to help identify action thresholds and develop a more targeted integrated pest management program.

Exposing berries to solar radiation improves most berry composition traits. Many of these effects have been linked to photomorphogenic mechanisms and berry temperature.