@article {Hedajev.2014.14034, author = {Bryan Hed and Henry K. Ngugi and James W. Travis}, title = {Short- and Long-Term Effects of Leaf Removal and Gibberellin on Chardonnay Grapes in the Lake Erie Region of Pennsylvania}, elocation-id = {ajev.2014.14034}, year = {2014}, doi = {10.5344/ajev.2014.14034}, publisher = {American Journal of Enology and Viticulture}, abstract = {Oversix seasons from 2007 to 2012, the effects of the timing of cluster zone leaf removal and bloom gibberellin applications on Botrytis bunch rot, cluster morphology, yield, and juice composition were evaluated on Vitis vinifera Chardonnay grapevines. All experimental plots received Botrytis spp. specific fungicide applications at pre -closure and veraison. Leaf removal at veraison, post-fruit set, or trace bloom, reduced Botrytis severity by an average of 14, 47, and 71\%, respectively, compared to no leaf removal. Leaf removal at trace bloom(LRTB) reduced Botrytis incidence and severity in five and four seasons, respectively, and was as effective as (2007 to 2010), or more effective than (2011 and 2012) two additional fungicide applications (at bloom and at pre-harvest), suggesting potential for reducing fungicide inputs. Gibberellin was less effective than LRTB, but reduced the incidence of Botrytis in 2008 (5 mg/L), and the severity of Botrytis in 2010 (25 mg/L). Botrytis development increases with number of berries per cluster and berries per centimeter of the cluster (compactness). Berries per cluster was reduced by LRTB in 2007, 2010, and 2011, and by gibberellin in 2007 (10 mg/L) and 2011 (25 mg/L). Berries per centimeter was reduced by LRTB and gibberellin in 2007, 2008, and 2011. Leaf removal at post fruit set produced the most noteworthy effects on juice composition, reducing titratable acidity in 2007, 2011, and 2012. Yields were reduced by LRTB in 2008, but no significant yield effects were observed in subsequent seasons. The efficacy of LRTB for reducing Botrytis bunch rot was highest in years with the most compact clusters, suggesting that the value of this treatment increases with increasing potential for bunch rot development.}, issn = {0002-9254}, URL = {https://www.ajevonline.org/content/early/2014/09/24/ajev.2014.14034}, eprint = {https://www.ajevonline.org/content/early/2014/09/24/ajev.2014.14034.full.pdf}, journal = {American Journal of Enology and Viticulture} }