Highlights of the Xth Terroir Congress (7/7 – 7/10)
in Tokaj, Hungary
At Terroir Congress, participants from all over the world discussed the most recent findings in viticulture. Attendees came from diverse backgrounds (PhD students, UNESCO and OIV members, vineyard owners, full-time researchers or winemakers) and from diverse fields (viticulture, enology, computer sciences, sociology).
The conference is called “Terroir” to emphasize that vine response to the environment is highly variable and must systematically be analyzed according to site-specific conditions. Depending upon pedo-climatic or vintage conditions, similar practices may either have a negligible impact or a huge footprint on vineyard performances. Consequently the value and usefulness of vineyard information vary according to vineyard locations. Understanding the complexity and limits of vine response to contrasted environments is key to select the most sustainable practices. This knowledge is increasingly strategic in the context of climatic changes, water scarcity and world competition.
This is the reason why Fruition was attending the Terroir Congress. Given the wide variety of topics discussed and the density of scientific information, we can only share a summary of the main ideas that caught our attention.
How can we develop and improve terroir zoning techniques?
Burgos (UVOC Nyons, Switzerland) explained how to account for vineyard topography while analyzing drone picture with a surface model. More specifically, different techniques were discussed to improve our ability at removing the effect of inter-row crop on NDVI.
Priori (RCAB Firenze, Italy) shared his mapping of terroir units in order to farm more uniformly areas of similar performances.
Santesteban (UPN Pamplona, Spain) explained how isotopic methods (measuring Carbon and Nitrogen) help track the source of vine Nitrogen uptake.
The implementation of other zoning techniques was also discussed based on:
- Time variations in NDVI (Martinez, UPM Madrid, Spain).
- Extrapolation of smart point information such as apical activity at key vineyard locations. Authors show powerful results to reduce water input and prioritize which areas need irrigation first (Trambouze, CAH Montblanc, France).
- Vineyard water status mapping technique. Brillante (UB Dijon, France) studied spatial variations in root water absorption sites in a hilly vineyard located in burgundy.
New insights to better understand the effects of environment on vine performances
Verdenal (Agroscope, Switzerland) studied how soil, climate and foliar spray can impact Yeast assimilable nitrogen (YAN) in the fruit.
Amoros (UCM Ciudad real, Spain) presented results regarding time variations of vine nutrient uptake throughout the season.
The effect of contrasted soil nitrate levels onto fruit YAN and Amino acid content were discussed by Perez-Alvarez (ICVV Rioja, Spain).
Garcia (CIVC Epernay, France) showed how it is possible to map precisely vine stem diameter variations (or the effect of soil variability onto biomass development) across an entire vineyard.
Various authors studied climate variability within uniform viticulture area in Portugal (Jones, DES Ahsland, OR-USA), New Zealand (Sturman, CAR Christchurch), France (Neethling, UMT Vinitera, Beaucouze, Bois, UB Dijon, de Resseguier, ISVV Villenave d’ornon), Greece (Anderson, DES Ahsland, OR-USA), Spain (Hernando, UPM Madrid) and Argentina (Grassin, Alta Vista, Lujan de C). Those comparisons are useful because they help identifying which viticulture areas most resemble yours. You may be surprised to learn that some areas in Greece are climatically similar to Oregon while other Greek areas are less warm than Napa but warmer than Paso Robles…
Recent developments in phenological models aim at evaluating new methods to improve our ability at predicting budbreak date (Ladanyi, U. Budapest, Hungary) as well as the effect of seasonal temperatures on vine phenology (Malheiro, CITAB Vila Real, Portugal; Parker, IPFR, Lincoln, New Zealand), biomass production (Miranda, UPN Pamplona, Spain) or maturation kinetics (Tamborra, CRA-UTV Barletta, Italy).
How can we adjust some practices to global climatic changes?
New vineyard practices are constantly being evaluated to anticipate and adjust to climatic changes. For instance, Nitrogen availability is directly affected by rain and temperature regimes. To understand the specific effect of nitrogen deficiency on aroma potential, Helwi (ISVV Villenave d’Ornon, France) is studying flavor development in absence of water deficit.
A method to analyze the effects of crop coefficient and irrigation on vine water use was discussed as a preliminary step to compare vintages, practices and terroir effects on maturation (Scholasch, Fruition Sciences Montpellier, France).
Adrian (UMR Agrosup, Dijon, France) discussed the potential use of volatile organic compounds (VOC) by plants under stress. Principles of such analysis rely upon the fact that vine “stress” – either from a biotic origin (like fungi) or abiotic origin (like water stress) – elicits a plant immune response which can be detected through atmospheric variations in VOC. Studying VOC offers promising insight to improve our understanding of plant resistance to stress.
Under contrasted climates, the effect of vineyard practices on vineyard performance was also discussed, such as irrigation (Balint, OSU, Central point, OR-USA; Herrera, DAES Udine, Italy; Santesteban, UPN Pamplona, Spain) early defoliation (Lopes, CBAA Lisboa, Portugal) or late winter pruning (Palliotti, DSAAA Perugia, Italy).
How can we enhance terroir and vintage effect?
Comparing world-class vineyards and using blind tasting technique with an experienced wine panel, Ballester and Jacquest (CSGA-UNESCO Dijon, France) demonstrated that no sensory reality could be attached to the taste of historically famous appellations. They discussed how mental representation of a wine taste could simply be inherited from 19th century wine writers comments or obsolete regulations no longer affecting winemaking practices today.
However, new techniques analyzing wine metabolic signature can reveal the memories of environmental factors related to terroir and vintage (Roullier-Gall, IUVV Agrosup Dijon, France). Those insights will help better understand how the environment impacts the taste of wine.
Through research and development, the implementation of precision viticulture method is increasingly becoming a routine practice worldwide and we observe an explosion of new mapping tools and techniques.
In this new context, the challenge is to precisely understand why, what and how new practices can be implemented in the vineyard. For instance, to improve vineyard performance, the management of within vineyard spatial variability is becoming standard practice. However, before implementing new farming methods you must understand the cost of investing into higher resolution maps vs. the benefits to expect from practices attached to new information.
To find that sweet spot, a scientific expertise on vineyard monitoring becomes a competitive asset. Why is it relevant? The vine is plastic. It can modulate its response and adapt to very contrasted environments and management techniques. The key to remain competitive in the future relies upon our ability to understand what site-specific parameters are more likely to bear a unique footprint on fruit composition.