1. Department of Horticulture, Viticulture and Oenology, University of Adelaide, Waite Campus, PMB 1, Glen Osmond, South Australia, 5064, Cooperative Research Centre for Viticulture, P.O. Box 154, Glen Osmond, South Australia 5064, and the Australian Wine Research Institute, P.O. Box 197, Glen Osmond, South Australia, 5064