PT - JOURNAL ARTICLE AU - Martin P. Mendez-Costabel AU - Kerry L. Wilkinson AU - Sue E.P. Bastian AU - Michael McCarthy AU - Chris M. Ford AU - Nick Dokoozlian TI - Seasonal and Regional Variation of Green Aroma Compounds in Commercial Vineyards of <em>Vitis Vinifera</em> L. Merlot in California AID - 10.5344/ajev.2013.12109 DP - 2013 Aug 19 TA - American Journal of Enology and Viticulture PG - ajev.2013.12109 4099 - http://www.ajevonline.org/content/early/2013/08/14/ajev.2013.12109.short 4100 - http://www.ajevonline.org/content/early/2013/08/14/ajev.2013.12109.full 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 (IBMP) and C6 compounds. Sixty nine commercial Vitis vinifera L. Merlot vineyards located in three distinctly different wine grape growing regions within the Central Valley of California were sampled at commercial harvest, fruit samples analyzed for green aroma compounds and standard chemometrics, and several weather parameters such as growing degree days and rainfall 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.