Samuel Hoffman, Elizabeth Tomasino,* James Osborne, Robert Martin, and Patty Skinkis
*Oregon State University, 100 Wiegand Hall, 3051 SW Campus Way, Corvallis, OR 97331 (Elizabeth.Tomasino@oregonstate.edu)

Grapevine red blotch virus (GRBV) poses a potential threat to the United States wine industry. Grapes harvested from GRBV-infected vines often have reduced sugar and anthocyanins, but impacts to wine sensory properties are unknown. This study investigated the sensory impact of viticultural management practices on GRBV in Oregon Willamette Valley Pinot noir. The viticultural practice consisted of application of abscisic acid (ABA) to the fruit zone until dripping. ABA was applied to GRBV (+) vines during the 2018 and 2019 growing season in a randomized complete block design during veraison and compared to an unsprayed control. Grapevine virus status was identified via PCR of leaf tissues from individual vines collected in summer 2018. This resulted in two treatments: GRBV (+) control and GRBV (+) ABA. Wines made from the treatments underwent sensory analysis by red wine consumers. Sensory analysis consisted of preference/liking, aroma check-all-that-apply (CATA), color intensity, and mouthfeel just-about-right (JAR) questions for body, bitterness, astringency, sourness, and heat. No significant differences in preference/liking, bitterness, astringency, heat, or sourness were noted during either year. Wine body was significantly different in 2018, with the GRBV (+) control wines characterized as having less body than GRBV (+) ABA wines. This difference was not noticed in the 2019 wines. There were significant color differences between both 2018 and 2019 wines. In 2018, the GRBV (+) control sample was rated more purple in color, while in 2019, the opposite occurred. Correspondence analysis was used to visualize the aroma CATA results for both years. CATA results showed aromatic trends in both years for the respective groups; however, none were considered statistically significant. While ABA may impact grape maturation, it does not appear to alter the wine sensory characteristics of wines produced with grapes from GRBV (+) vines.

Funding Support: Oregon Wine Research Institute and Private Industry Donations