Ashley Vineyards is in the process of choosing clonal types for our plant order to be delivered next Spring. We purchase our plants through Ryan at Inland Desert Nursery in Eastern Washington. This is a good time to share my thoughts on clones and the choices we are grappling with at the moment.
A bit of physiology first:
It is the flesh, skin, and seed of the grape that is of interest to the winemaker and the characteristics of which that make for a unique wine profile. Grape plants fertilize themselves, meaning they do not need the pollen from another plant; they have their own anther and stamen to create a seed. Although the grape is self-fertilizing, there is still a ‘shuffling’ of the genes so to speak when the seed is forming. This shuffling allows for variability in characteristics (phenotypes) of the plant. These different characteristics may create changes and dictate outcomes such as:
When the plant breaks bud in the spring,
When the plant ripens in the fall,
How much fruit the plant carries,
How much energy the plant puts into vegetative growth,
How thick the skin is on the grape,
How much flesh is present in the final grape,
How large the seed is,
What tannins are deposited into the seed,
What phenols and pigments are deposited into the flesh and skin,
How much of which types of acids are present in the juice at harvest,
How fast the pH drops in the fruit,
How much sugars are able to build prior to harvest.
For these reasons, grapes planted in vineyards today are clones, meaning they are a genetically identical cutting from a plant that exhibits the characteristics desired by the grower. When a breeder finds characteristics that are desirable being expressed by a plant, they take cuttings off the plant and root the cuttings. This way all plants in the vineyard are expressing the same desirable characteristics without having to spend years stabilizing the genetics through a breeding program. This allows for an easier time at harvest and throughout the growing season as there will be less variability in the vineyard, (they should break, and ripen at roughly the same time and speed).
There are a couple trains of thought when choosing clonal types.
One is to choose the clonal suited best for your terroir and plant it. The other is to mix clonal types to not only allow for changes in the growing season, (for example, some clones fair better with the early frost that occurred that year and you still get a decent fruit load) but also Kramer mentions in his book, Making sense of Wine, that planting multiple clonal types in one vineyard can yield the full expression of the terroir and the full bouquet of flavor components in the grape. Both of which will lend a more robust flavor profile in the final wine product. This method may allow for more variability regarding ripening toward the end of the year, but that can be mitigated by fruit thinning once after fruit set and again after veraison, dropping any fruit that is over or under ripe. This will allow for a more uniform crop at harvest. Since the cultivation method of dropping fruit will be done anyway, it makes sense to plant multiple clonal types with desired characteristics, and make the fruit uniform by thinning later on.
Ashley Vineyards 