Mass Selection
Massal selection allows a winemaker to preserve and multiply plants presenting characteristics that seem interesting to them in relation to their objectives. It enables the multiplication of plant material as an alternative to clones available on the market. It falls under private nursery, meaning that the selected plant material is multiplied and planted on the farm from which it originates.
Massal selection has an additional interest for preserving old grape varieties coming from old plots.
Description
The viticulturist selects their own plant material by choosing interesting vines in plots corresponding to their production objectives. They then take cuttings and entrust them to their nurseryman for multiplication. At this stage of the work, it is relevant to carry out sanitary tests to verify that the plant material is free from viruses.
It takes about two to three years to select the interesting vines in the field. Then, an additional year is needed to have plants to replant on the farm. Note that this type of selection can be used by winemakers to preserve the viticultural heritage of a very old vine or to improve the quality of a given grape variety.
Objectives
- Preserve plant material evaluated as interesting, which requires the expertise of the winemaker.
- Increase the diversity of plant material within the farm.
- Multiply and replant this selected material.
Implementation
- In season, identification of vines presenting interesting potential (phenology/earliness, fertility and production, sensitivity to diseases and water stress, maturity profile) and marking (row identification, vine).
- If possible, confirmation of this interest over 2 vintages n and n+1.
- Winter n+1: Cutting and conservation of cuttings (4°C / sufficient humidity) + sampling of cuttings for each vine to perform sanitary tests (grapevine fanleaf virus, leafroll virus) and rejection of unhealthy individuals (analysis about €21 excl. tax).
- Spring n+2: Grafting of the material at the nurseryman for planting spring n+3 or in-place grafting on rooted plants (rootstock).
Advantages and disadvantages
Economic
Optimized match between the planted material and production objectives and valorization at the bottle.
Since the selection process spans several years, plantings and renewal of plots are slower, which represents an additional cost for the winemaker.
Agronomic
Allows to slow down the erosion of the plant heritage vine.
Obtain a quality of grape that corresponds to the primary winemaking objectives.
Environmental
Genetic diversity in the plot.
If sanitary tests are not implemented, there is a risk of transmission of viruses : leafroll or grapevine fanleaf virus.
Investments
There are 2 possible methods for grafting :
- Welded graft: After selecting the vines, the nurseryman collects the cuttings and performs the grafting, thus obtaining welded grafted plants. These plants enter production at best in the 2nd year.
- In-place grafting on rooted plants : Purchase of rootstock and planting. Then you have to wait for the rootstock to have a sufficient diameter to be grafted in the field, which can take up to 3 years. The rootstocks will then be grafted with cuttings from massal selection. According to available experimental data, this technique is well suited to limiting soils (poor soil, frequent water stress, etc.). Indeed, the rootstock develops and establishes itself alone for at least 3 years, and confers additional vigor to the scion that will be grafted.
The investment for these 2 types of grafting should be considered in light of production timelines. The purchase of welded grafts is cheaper and suits plots without any agronomic bias very well. In-place grafting, although more expensive, can be interesting in all limiting situations because it confers additional vigor to the scion.
Regulations
The viticultural nurseryman produces plants from massal selection. It should be noted that this selection currently falls under the administrative framework of private nursery and is not yet subject to specific regulation, which could change in the future. From a regulatory point of view, the viticulturist must imperatively establish a private nursery declaration with FranceAgriMer[1].
Conclusion
In the current context, it is possible that in the coming years, massal selection will incorporate additional criteria related to climate change. For example : The resilience of vines identified to various climatic stresses, droughts, heatwaves or late frost events.
Related articles
Sources
This article was written with the kind contribution of Garance Marcantoni, Project Manager Organic Farming. Viticultural advisor - Reference for organic viticulture in PACA and nationally. Reference for plant material.
Other sources :
- Massal selection - La revue du vin de France.
- Wine terms : massal and clonal selections - IdealWine Journal.
- Massal selection - Osae.
- https://pepiniereshebinger.fr/ - Nursery specializing in massal selection
