Courtesy Washington State UniversityA group of international researchers examine own-rooted vines at Washington State University's Prosser facility.Washington state's winegrape growers have bucked the rootstock trend, and most of their vineyards are still on own-root vines.
If phylloxera should strike and they have to convert over to grafted plants, winegrape growers have been concerned about wine quality suffering, according to a news release.
Not to worry, says a recently released study led by Washington State University viticulturist Markus Keller, who's based in Prosser.
Continuing on earlier work begun in 1999, Keller's team found no difference in wines made from grapes grown on own-rooted vines and from vines grafted onto rootstocks.
"The short answer is don't be afraid of rootstocks," he said in the news release.
The study's results, which were published in the March issue of the American Journal of Enology and Viticulture, found that climate and not rootstock affected the wine's quality.
Keller and enologist Jim Harbertson, a cooperator in the study, determined that scion, vineyard location and vintage were the major factors that influenced grape and wine quality.