The popularity of the Syrah variety in California led to widespread plantings in the 1990s, and now much of that acreage has come into production. But, the variety has been plagued by mysterious maladies, and no one yet has definitive answers.
To address the issues, University of California researchers recently organized an international Syrah Vine Health Symposium. Mark Battany, San Luis Obispo and Santa Barbara County viticulture farm advisor, categorized the symptoms that have been observed in California.
“Leafroll virus symptoms are the most prevalent problem we see in Syrah in California. Fruit quality is very diminished, but the vines survive — they actually grow very well. We tend to see more red leaf symptoms as stress increases, so the drier the vines are or the heavier the crop load, the more we see symptoms. Some are identifiable in the lab as leafroll; some are not.”
Other Syrah disorders in California include leaf burn and decline. Leaf burn occurs in the hotter, drier inland areas of California, according to Battany.
“I don’t see this in the coastal areas. It occurs late in the season, and it is very inconsistent from season to season.”
Syrah decline in California is similar to what researchers have been observing in France since 1993.
“After several years of good growth, we will start to see symptoms in vines that are 3-9 years old,” Battany says. “Vines are dying off for no apparent reason. But, the fruit quality is very good, or in some cases, stupendous. A lot of gold medals are being won from dying vines.”