Winegrowers Supplies - Clones and selection massales - thoughts from a French vine nursery
Clones are now well established. They offer a regularity of production, a good ripeness/yield and secure vine health. But clones have, in many cases, yields which are difficult to control and suffer from too great homogeny. It is recommended to plant several different clones to obtain more complexity and stability, but with some varieties there are insufficient clones available.
For great vintage wines we try to obtain outputs of less than 60 hl/ha, this is not easy with clones which were selected for their high yield, double the above output.
At the request of certain of our clients we re-started massales selection. Contrary to clones which are theoretically identical plants, massales selection mixes many different plants. For this we select plants having the potential of a high quality. We take into account the general health of the plant, the number and size of the berries, how advanced the maturation is, and the sugar content. We do 2 to 4 refractometer readings per plant which represents more than 20,000 measurements.
For each variety nature has given us a great number of different characteristics: more or less productive plants, late or early flowering, rich in sugar, perfumed, resistant to certain diseases etc. New planting in the past 25 years has involved a great majority of vines from clonal selections, hence we are in the process of progressively eliminating the diversity of our vineyards. In effect each plant of a clone is genetically identical to the others and remains so. With identical plants it becomes impossible to create a new selection in the future.
The world evolves and in 20 years time the criteria of production may be different. In order that we may one day also make selections we must reproduce the diversity while it still exists.