TY - JOUR T1 - Canopy Management and Enzyme Impacts on Merlot, Cabernet franc, and Cabernet Sauvignon. I. Yield and Berry Composition JF - American Journal of Enology and Viticulture JO - Am. J. Enol. Vitic. DO - 10.5344/ajev.2010.10024 SP - ajev.2010.10024 AU - Frederick Di Profio AU - Andrew G. Reynolds AU - Angela Kasimos Y1 - 2011/02/23 UR - http://www.ajevonline.org/content/early/2011/02/23/ajev.2010.10024.abstract N2 - Merlot, Cabernet franc, and Cabernet Sauvignon vines in Niagara-on-the-Lake Ontario, were subjected to four treatments [hedged control; cluster thin at veraison (CT); basal leaf removal (BLR); CT+BLR] in a randomized complete block experiment. Musts from each treatment replicate (CT+BLR excepted) were thereafter either left untreated, or treated with one of ColorPro or ColorX enzymes. Cluster thinning reduced yield per vine and crop load but had inconsistent effects on cluster weight, berries per cluster and berry weight. Leaf removal alone had few noteworthy effects on yield components. The cluster thinned treatments generally had the highest soluble solids (Brix) in berries and musts. Cluster thinned and CT+BLR treatments in most cases also had the highest berry and must anthocyanin and phenol concentrations, as well as the highest color intensities (A420 + A520). Leaf removal resulted in small increases in berry and must color intensity, anthocyanin and phenol concentrations, with little or no increase in Brix. Cluster thinned and BLR treatments both reduced TA and increased pH relative to control, but BLR tended to be more effective than cluster thinning in this respect. The CT+BLR treatments usually resulted in the lowest berry and must titratable acidity (TA) and the highest pH. Enzyme treatments increased must TA and reduced pH, and typically increased color intensity, total anthocyanins and phenols, but generally viticultural treatments had a greater magnitude of effect. The CT+BLR treatment has potential to substantially improve fruit composition; a negative consequence to this might be that excessive leaf removal could result in lowered Brix and TA, as well as undesirable increases in pH. Enzyme treatment has potential for increased color intensity, but with occasional increases in TA. ER -