Effect of multi-level and multi-scale spectral data source on vineyard state assessment

The wine industry works to minimize pesticides and adapt to climate change. Breeding programs have developed disease-resistant grape varieties, particularly against downy and powdery mildew, to minimize pesticide applications [1]. However, their enological potential remains underexplored.

Vine downy mildew is one of the most frequent diseases in intensive vineyards. Bordeaux mixture (B.m.), in order to control the disease has been applied onto vineyards since the end of the 19th century. The intensive use of Cu-fungicides could influence the physiology of grapevine. It is also possible that high amounts of foliar Cu sprays trigger stress responses in vine leaves.

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.

Mediterranean vineyards have been traditionally grown under rainfed conditions, but in recent decades the irrigated area has increased significantly, seeking to minimize the adverse effects of severe water stress on grape quality and yield. Given the large area occupied by vineyards, and the increasing scarcity of water resources, it is necessary to develop strategies for the optimization and efficient use of water to reduce the risk of its overexploitation. The present study aims at valorizing previous knowledge generated in different research projects by means of a meta-analysis of the effects of water status management on vineyard performance.

AIM: Lactiplantibacillus plantarum species is wordwide used as starter for malolactic fermentation [1,2]. For the first time, in the present study, the use of L. plantarum (ML PrimeTM, Lallemand wine) to produce white wines with post-fermentative maceration extended until 60 days has been investigated.