RT Journal Article SR Electronic T1 Seasonal and Regional Variation of Green Aroma Compounds in Commercial Vineyards of Vitis vinifera L. Merlot in California JF American Journal of Enology and Viticulture JO Am. J. Enol. Vitic. FD American Society for Enology and Viticulture SP 430 OP 436 DO 10.5344/ajev.2013.12109 VO 64 IS 4 A1 Martin P. Mendez-Costabel A1 Kerry L. Wilkinson A1 Sue E.P. Bastian A1 Michael McCarthy A1 Chris M. Ford A1 Nick Dokoozlian YR 2013 UL http://www.ajevonline.org/content/64/4/430.abstract AB A field study was conducted from 2007 to 2010 to examine regional and seasonal variability of the main compounds responsible for green aromas in grapes and wines, 3-isobutyl-2-methoxypyrazine and C6 compounds. Sixty-nine commercial Vitis vinifera L. Merlot vineyards located in three distinctly different winegrape growing regions within the Central Valley of California were sampled at commercial harvest, fruit samples were analyzed for green aroma compounds and standard chemometrics, and several weather parameters such as growing degree days and rainfall were recorded at the vineyard level. Seasonal variation was found to be more important than regional variation, and similar trends among regions were found within each season. Temperature during the spring, a period of active growth, was found to be a significant driver of fruit green aroma compounds at harvest, likely due to its interactions with vine vigor and fruit shading.