(Wines&Vines) - A researcher in New Zealand seems to have developed a regime to keep leafroll virus under control—but it’s not clear whether the same approach will be equally successful in California due to differences in conditions, notably a different insect vector.

Dr. Vaughn Bell spoke March 19 before the Napa Valley Vineyard Technical Group during a talk arranged by University of California Cooperative Extension. (Monica Cooper is the local viticulture advisor.)

Dr. Bell is a scientist at the New Zealand Institute for Plant and Food Research and was called into action when leafroll emerged as a large issue in that country.

“Leafroll was seen as a real threat to our business, which focuses on quality wines. It delays ripening, a real concern in our cool growing areas,” he said.

Bell added that New Zealand has 87,487 acres planted to grapevines and exports $1 billion worth of wine annually. The largest growing area is Marlborough, a cool growing area on the South Island—but even Hawkes Bay on the North Island only typically reaches about 85° F during the growing season.