Ling Huang, Patty Skinkis, James Osborne, Qin Zhou, Yanping Qian, and Michael Qian*
*Oregon State University, 3051 NW Campus Way, Corvallis, OR 97331 (michael.qian@oregonstate.edu)

Grapevine red blotch disease has a large impact on grape development and lightens grape berry color. The typical symptoms are red spots and red veins on leaves. We examined the impact of two different leaf-removal treatments on red blotch-affected vines on wine aroma composition. The leaf-removal trial consisted of an early leaf-removal applied prebloom, in which all leaves in the cluster zone were removed by hand, or mechanical leaf removal at fruit set (control). Early leaf removal in- creased the levels of monomeric anthocyanin and phenolic compounds in wines. This suggests early leaf removal may lessen the effect of red blotch disease on grape color. No obvious significant differences in wine volatile profile were found between treatments. Early leaf removal led to higher levels of bound-form C13-norisoprenoids in wines than the control.

Funding Support: Oregon State University