ARS | Publication request: Effect of Deficit Irrigation and Kaolin-based Foliar Reflectant Particle Film on Aroma of cv. Merlot (Vitis vinifera L.)

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 9, 2010
Publication Date: June 1, 2010
Citation: Ou, C., Song, Q., Du, X., Shellie, K., Ross, C., Qian, M. 2010. Effect of deficit irrigation and kaolin-based foliar reflectant particle film on aroma of cv. Merlot (Vitis vinifera L.). International Cool Climate Symposium Program and Technical Abstracts Book. p. 27-28.

Technical Abstract: Water deficit during development of red-skinned wine grape enhances berry composition for wine production but increases risk of fruit exposure to deleterious levels of heat and/or solar radiation. Foliar application of a kaolin-based particle film has been shown in many crops to alleviate stress symptoms, but its influence on wine composition is unknown. In this study, we investigated whether foliar application of a kaolin-based particle film affected wine volatile aroma compounds and wine sensory attributes of the cultivar Merlot grown under differing levels of water deficit. Merlot vines were grown in the high desert region of southwestern Idaho and irrigated to meet 100, 70, or 35% of estimated crop evapotranspiration (ETc) from fruitset through harvest or 35% ETc until berry color change and then 70% ETc until harvest. The free volatile composition in the grapes were analyzed using stir bar sorptive extraction (SBSE)-GC-MS technique, and the precursors were isolated and hydrolyzed by enzyme under mild acidic conditions followed by SBSE-GC-MS analysis. Wines were analyzed over three consecutive growing seasons. The results demonstrated that despite vintage differences in volatile composition, in each of three years of this study, deficit irrigation during berry development had a consistent effect on wine volatile composition. The amount of ß-damascenone, citronellol, nerol, geraniol and their precursors were higher in deficit irrigated grapes and the wines. Deficit irrigation increased linalool glycoside in the grapes but not in the wine. Deficit irrigation had no impact on the concentration of ß-ionone. Particle film did not affect wine volatile composition regardless of irrigation level.