(Wines&Vines) - In the past three years, the vine sickness Pinot Leaf Curl has struck more often and with greater severity in Sonoma County’s valuable Pinot Noir vineyards. The ailment also can affect Pinot Blanc vines and has been observed less frequently in Pinot Meunier. Pinot Leaf Curl, or PLC, appears during spring; symptoms can range from stunted or distorted leaf growth to severe instances in which an entire shoot and node can die. Rhonda Smith, University of California extension advisor for Sonoma County, made the ailment a focus of Sonoma County Grape Day on Feb. 16