© Académie du chenin. Créé avec Wix.com

Modérators : André Deyrieux & Etienne Goulet

4. Olivier Zekri (Pépinières Mercier) -The UNIK massal selection - Poster

Clonal selection, that began over 50 years ago, allowed a sanitary remediation of the French vineyard and better control of the agronomical and oenological quality of the vegetative material, meanwhile reducing the intra-varietal diversity. In order to conserve this genetical diversity and use it to develop new vegetative material answering viticulturists’ needs and adaptation to climatic changes, Mercier frères nursery started a UNIK® massal selection program for Chenin in 2004.

 

The UNIK® massal selection process starts with prospecting phenotypically different individuals in parcels of over 50 years. For this selection, 260 vines were selected in several parcels from the main Chenin production regions of Val de Loire. The sanitary state of the material being the base of a persisting vineyard, a first sanitary selection was made with a primary and secondary viruses’ analysis. It led to the plantation of an experimentation parcel in Savennières, with 22 genotypes, randomly planted in 5 blocks of 10 vines, in comparison with a reference clone.  At the third leaf, 3 years of agronomical study are made to evaluate the yield, the total grapes’ weight, one grape’s weight, 100 berries weight, the potential level of alcohol and total acidity. The aim of the agronomical selection was to obtain vines that were resistant to Botrytis and flower abortion, with moderate production, less compact clusters, non-early debudding and oenologically superior to the clonal reference. After a first agronomical selection, 5 genotypes were micro vinified for 3 years and compared in blind testing.

 

The results obtained during this 6 years study, supported with statistical analysis, allowed the selection of 5 Botrytis and flower abortion resistant genotypes, with low compacity clusters, moderate production and better in tasting than the reference clone. The agronomical and oenological features of each genotypes is expanded by a global homogenization of harvest quality and maturity.  

5. Lilian Bérillon - Terroir Expression - Poster

To build sustainably vineyard is what gives me most motivation. This is the current challenge that all viticulture knows today. This challenge is climatic, but also about heritage, environment and a society topic.
It must also meet the needs of winegrowers seeking excellence in the expression of the terroir, which is fundamental for the future of French vineyards.


That's why I've been putting in place for years a model of experimental plant production that explores new ways.
I build it based on varietal diversity from the long history of vitis vinifera, especially intravarietal diversity. But also by working with processes opening new possibilities.


The basis is to rely on prospecting work in the vineyards. The process is established according to very strict specifications, in order to obtain an extremely fine selection on agronomic and oenological levels. Thus, in the Loire, 150 individuals of Chenin Blanc with different genotypes have been identified within recognized domains and from prestigious appellations: Savennières, Coteaux du Layon Villages, Coteaux de l'Aubance, Bonnezeaux, Saumur-Champigny, Chinon, Coteaux Loir, Azey le Rideau and Montlouis.


These selections enriched the diversity of the conservatory at the nursery. They make it possible to populate the new plantations with the biodiversity necessary for the balance of an entire system. This work of Chenin Blanc's Massal Selection takes place every year at the vineyards of the Val de Loire just before the harvest. The prospecting is done as follows:
-    Observation of individuals over 50 years
-    Visual inspection of health status
-    Observation of the harvest, the port, the balance ...
-    This control is repeated 2 more years
-    A first health check with primary and secondary viral analysis is carried out after 3 years of observation
-    The healthy plant is isolated and multiplied by grafting to strains by strains in the workshops
-    A parcel of graft’s vine-mother, populated by each of the selected individuals, is implanted after having been treated with hot water. Before this planting, new viral and sanitary tests are carried out in order to secure the quality of the plant material.


At the same time, we are developing an orientation that can improve the sustainability of plantations. We promote "rooted" planting, which means first planting the rootstocks and then grafting vitis vinifera into place. Rather than planting grafted on the table. We observed that the rooting rate success of rooted plants is much higher, but also that the level of diseases developed on roots was anecdotal, while the contamination was 10 to 15% with grafted grafts.


We decided to treat the entire production with hot water, to seek to be autonomous in raw material (grafts and rootstocks) and in our needs of arable land, to graft the whole of its production plants by whip and tongue graft method, to draw up eco-responsible specifications (organic and biodynamic cultivation methods of our nursery which, for regulatory reasons, cannot claim certification), to ensure a tailor-made accompaniment of the winegrowers of the Loire Valley through a team of agro engineers.


I am therefore engaged in a work on "plant material" that explores new ways to meet the challenges of current viticulture and future. It requires a constant and long-term validation of the routes explored, and this in the context of a real enterprise with its economic imperatives, and in direct connection with the news of the research, the profession, its challenges and its debates, and the vine growers.

the Program

Session I - biology and behavior of chenin blanc in a changing environment