PT  - JOURNAL ARTICLE
AU  - Scheiner, Justin J.
AU  - Sacks, Gavin L.
AU  - Pan, Bruce
AU  - Ennahli, Said
AU  - Tarlton, Libby
AU  - Wise, Alice
AU  - Lerch, Steven D.
AU  - Vanden Heuvel, Justine E.
TI  - Impact of Severity and Timing of Basal Leaf Removal on 3-Isobutyl-2-Methoxypyrazine Concentrations in Red Winegrapes
AID  - 10.5344/ajev.2010.61.3.358
DP  - 2010 Sep 01
TA  - American Journal of Enology and Viticulture
PG  - 358--364
VI  - 61
IP  - 3
4099  - http://www.ajevonline.org/content/61/3/358.short
4100  - http://www.ajevonline.org/content/61/3/358.full
SO  - Am J Enol Vitic.2010 Sep 01; 61
AB  - Field studies were conducted on Vitis vinifera L. cvs. Cabernet franc and Merlot to evaluate the effects of basal leaf removal timing and severity on 3-isobutyl-2-methoxypyrazine (IBMP) concentration in grape berries. Treatments consisted of removing either 50% or 100% of leaves from the fruiting zone at either 10 days after anthesis, 40 days after anthesis, or 60 days after anthesis. In the second year of the Cabernet franc study, a 15-day postveraison leaf removal treatment was also included. In both years of the Cabernet franc study, significant reductions in IBMP (range = 28 to 53%) were observed before veraison compared with the control in both 10 days after anthesis treatments (50% and 100% leaf removal). In 2007, all leaf removal treatments significantly reduced IBMP concentrations compared with the control (46 to 88%) in Cabernet franc berries at harvest, with the greatest reduction observed in the 100% leaf removal treatments at 10 days after anthesis and 40 days after anthesis. In 2008, the 100% leaf removal treatment at 10 days after anthesis and the 50 and 100% leaf removal treatments at 40 days after anthesis significantly reduced IBMP concentrations (34 to 60%) in mature Cabernet franc berries. In the Merlot trial, all leaf removal treatments significantly reduced IBMP concentrations (38 to 52%) at harvest. In summary, early season (10 to 40 day after anthesis) basal leaf removal reduced IBMP accumulation preveraison compared with the control in both studies, suggesting that early leaf removal is a more effective management strategy to reduce IBMP accumulation in grape berries than leaf removal later in the season.