There are (according to a study in Australia two years ago) 1450 different grape varieties used for wine production globally. Just ten varieties make up 44% of the total (based on area of grapes planted). Add a further 50 varieties, and these then account for 76% of total global vineyards. So, only 4% of the commercially grown grape varieties account for more than three quarters of the vineyard planting.
If you want to impress friends with your knowledge, the big 10 are Cabernet Sauvignon, Merlot, Airen, Tempranillo, Chardonnay, Syrah, Garnacha Tinta, Sauvignon Blanc, Trebbiano Toscano and Pinot Noir.
Does this matter?
Consider the banana, one of the most popular fruits in the world. To ensure consistency of product and economy of scale, almost all commercial production is of a single variety. Commercial bananas are sterile, without viable seeds. Banana plants are grown using a technique called tissue propagation. All the plants are clones with the same DNA structure – an extreme case of a monoculture.
The dominant commercial banana variety used to be Gros Michel. In the 1960s, a blight known as Panama Disease (fusarium wilt) completely wiped out this strain of banana. Producers switched to another variety called Cavendish (which produced smaller, less tasty bananas – but resistant to Panama Disease). That’s the one you find in your supermarket today.
Fifty years on, a variant of Panama Disease is wreaking havoc with the Cavendish banana plants around the world. No cure has been found. Maybe this will be the end of bananas as we know them.
So why does this mean problems for grapes? Like bananas, most grapes vines are not grown from seeds. Cuttings from one vine are grafted onto a vine rootstock, producing clones of the parent vine. The focus on a limited number of grape varieties is a step down the road to reducing biodiversity and creating a monoculture. We have experienced what happened when a new pest was introduced to vines – phylloxera nearly wiped vineyards globally one hundred and fifty years ago. Since then, the diversity of grape varieties in production has shrunk. It has become easier and easier for plants to move around the world. We can only hope that no new vine disease will emerge to decimate vineyards around the world.