New Merlot Clones for the Swiss Certification Sector

Five Merlot clones bred in Switzerland are currently being distributed by the certification sector. A multiyear trial conducted by Agroscope in Gudo (Canton of Ticino) has made it possible to compare them with French and Italian reference clones and to highlight their very good performances.

Merlot is a grape variety native to the southwest of France. Introduced in vineyards to the south of the Swiss Alps (Ticino and Mesolcina) at the beginning of the 20th century, it currently dominates the vine population of this region, covering 78% of the wine-growing area. Over the past thirty years, areas planted with Merlot have grown steadily in Switzerland. This growth is due in particular to the expansion of the variety in vineyards north of the Alps, spurred on by climate warming in recent decades.

Breeding of trial candidates

Since 1955, projects aimed at exploring and safeguarding the clonal diversity of Merlot have been pursued in Ticino. With the additional contribution of clones identified by Ticino nurserymen, study collections were set up in Mezzana in 1959 and on Agroscope’s experimental field in Cugnasco in 1970.  A trial was set up in 2004 on Agroscope’s experimental field in Gudo (Canton of Ticino) to evaluate the behaviour of five Swiss clones (four of them bred in Ticino by Agroscope and one bred by the nurseryman Andreas Meier) compared to four French and two Italian reference clones.

Comparison of the clones

In the trial, the agronomic and oenological traits of the different clones were studied and compared. Numerous checks were carried out focusing on the parameters associated with the production potential and vegetative aspects as well as the analytical characteristics of the musts and wines, which were also evaluated via sensorial analyses.


  • A trial conducted at Agroscope’s vineyard in Gudo (TI) compared the agronomic and oenological performances of five clones bred in Switzerland by Agroscope and the wine nurseryman Andreas Meier with those of French and Italian reference clones.
  • The results of this trial show that all of the clones bred in Switzerland perform very well in agronomic terms.
  • Among the clones bred by Agroscope, RAC 19 and RAC 77 in particular reveal a qualitative potential comparable to that of the best French reference clones.
  • The five Swiss clones studied are currently distributed by the national certification sector.

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