What to do to solve the riddle of vine rootstock induced drought tolerance

The vineyard has experienced a general increase in yields mainly due to the elevated use of technology which caused a quality loss of grapes in more than one case. A large percentage of the Spanish vineyard is covered by a Denomination of Origin which limits the productive level of the vineyards as one of its regulations. The maximum production limit is a variable characteristic of each vineyard and is not usually regulated by agronomic criteria, and this explains the fact that each vineyard can reach high quality with a totally different yield from that set by the Denomination of Origin.

In temperate climates, such as in the North of Spain, the use of irrigation in the vineyard has not been required, due to the usual rainfall from June to August. In some large vineyards, irrigation management has been carried out, based on occasional support irrigation, or for the application of nutrients (fertigation). Currently it is necessary to implement decision support models to manage irrigation water in real time and avoid misuse of a scarce resource. Moreover, quality standards must be achieved, as in the previous rainfed viticulture.

Vineyards from mild temperature, high humidity locations receive often treatments with fungicides to prevent damages produced by fungi responsible for mildium, oidium and botrytis infections. In addition, insecticides are also applied to vineyards to fight again pests, which affect directly, or indirectly (as vectors of different diseases), their productivity. A fraction of the above compounds reaches the soil of vineyards, either during application, or when released from the canopy of vines due to rain-wash-off. Thereafter, depending on soil conditions (pH, organic matter) and environmental variables (regimen of rain, slope of vineyards), they might persist in this compartment, be degraded and/or transferred to water masses, modifying the biodiversity of soils and/or affecting the quality of water reservoirs.

Reducing sugar accumulation in grape (Vitis vinifera L.) berries may be a way to mitigate the effect of climate change. Managing canopy and crop load is an effective way to do so, however, reducing canopy size has been demonstrated to induce undesirable effects on anthocyanins. The aim of this study was to test if an application of exogenous ABA on the grape berries of defoliated vines (⅔ of the leaves removed) can result in slower sugar accumulation while maintaining grape and wine quality. An experiment with defoliation and exogenous ABA application on directly on clusters (factorial design 2×2) was performed with ‘Tempranillo’ fruit-bearing cuttings.

INTEGRAPE was a European interdisciplinary network for “data integration to maximize the power of omics for grapevine improvement” (CA17111, https://integrape.eu/), funded by the European COST Association from September 2018 to 2022. This Action successfully developed guidelines and tools for data management and promoted the best practices in grapevine omics studies with a holistic future vision of: “Imagine having all data on grapevine accessible in a single place”.