Effect of environmentally friendly vineyard protection strategies on yeast ecology during fermentation

Context and purpose of the study. The growing need for sustainable solutions in viticulture has led to increased interest in biostimulants that can enhance plant resilience to both abiotic and biotic stresses.

In the French AOCs, the production area of ​​the raw material can be subject to plot delimitation based on criteria of physical environment and use. On the other hand, many environmental zonings are developing and the AOCs are called upon include provisions relating to these concerns. Hedges, through their effects on local changes in the regional climate and on functional biodiversity, can impact the functioning of vines and orchards. It is for this reason that their consideration as a delimitation criterion is envisaged.

The work shows the results of a year of experimentation (2020) in a Syrah variety vineyard in La Roda (Castilla-La Mancha, Spain). The trial approach was on a randomized block design with two factors: Irrigation (I) and Pruning (P).
Irrigation schedules were adjusted to apply amounts close to 1,500 m3/ha. With this provision, 2 different irrigation treatments were proposed: I1) Start of irrigation from pea-sized grape to post-harvest (providing at least 20 % of the total amount of irrigation water to be provided post-harvest); I2) Start of irrigation from pea-sized grape to harvest (usual irrigation practice in the study area). Pruning was proposed with two treatments, one at the end of January (P1), which is pruning on a conventional date; and P2) pruning carried out at the beginning of budding. In total, 4 repetitions were designed with 4 elementary plots, each one of them representing one of the proposed treatments (I1P1; I1P2; I2P1; I2P2). In total, 16 plots were worked on and each elementary plot consisted of 30 strains, distributed in 3 lines.
The productive response was evaluated with the yield results of the harvest harvested at 23 ºBrix. The qualitative response was measured in the musts through the indices of technological (acidity, pH and potassium) and phenolic maturity and aromatic compounds in free and glycosylated fractions. The treatments tested had, in general, an effect on the different variables analyzed.

Background: hydroxycinnamic acids (HCA), present in pulp and skin of grapes, are relevant compounds in red winemaking

Warming trends over the winegrowing regions lead to an advance of grapevine phenology, diminution of yield and increased sugar content and must pH with a lower polyphenol content, especially anthocyanins. Canopy management practices are applied to control the source sink balance and improve the cluster microclimate to enhance berry composition. We hyphothesized that an early leaf removal might promote a delayed ripening through severe defoliation after fruitset; whereas, a late leaf removal at mid-ripening would reduce sugar accumulation.