Identification of Powdery Mildew Races or Biotypes from Grapes and Their Control by Minimum Required Fungicide Doses

Powdery mildew samples were collected during late summer 1992 and stored under -80° for laboratory evaluation. Buds and scale samples were collected during early spring (1993) and stored under laboratory conditions. The stored samples were rubbed onto the early shoots to observed mildew incidence and severity. The study is still underway. The mildew is now showing up and appropriate fungal sprays are being made. The results will be collected in July 1997.