(TDB) - Global wine production is showing signs of increasing homogeneity as international varieties expand their share of the world’s vineyards.

A study published in the latest issue of the Journal of Wine Economics reported that, despite “the competitive challenges for producers seeking to differentiate their product”, the 35 most widely planted grape varieties saw their share of the global vineyard area rise from 59% in 2000 to 66% by 2010.

In addition, 12 of the 44 countries featured in the study had more than one third of their total vineyard area planted with their respective most popular grape variety.

The study, titled Changing Varietal Distinctiveness of the World’s Wine Regions: Evidence from a New Global Database, drew on data from the decade up to 2010 from more than 600 wine regions in 44 countries and 1,300 individual grape varieties. In total, it claimed to cover “as much as 99% of global wine production”.

Echoing observations made by grape geneticist and Wine Grapes co-author José Vouillamoz, the report found that both Cabernet Sauvignon and Merlot more than doubled their share of plantings to head the league table, while Tempranillo and Chardonnay more than trebled their own proportion of vineyard area.

There was also a major leap in popularity for Syrah, which rose from 35^th most widely planted variety into sixth place. Sauvignon Blanc and Pinot Noir both moved up to take their places in the top 10.

By contrast, there were declines from Airén, which slipped from first place to third, while Grenache fell from second into seventh and Sultaniye – also known as Thompson seedless – plummeted from third to 35^th place.