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W i n e s & V i n e s n O V e M B e r 2 0 1 4 121 tively; N leachate concentrations from the gH treatment were 150% and 112% greater than NV and CULT, respectively. In 2013, gH N leachate concentrations were 573% and 464% greater than that of NV and CULT, respectively. The bare soil treatments of gH and CULT had similar dissolved, organic carbon concentrations to one another, and were greater than dis- solved organic carbon concentrations in the cover-crop treatments of NV and WC in both years. In 2012, imidacloprid insecticide was found in measurable concentrations in 28% of gH leachate samples, and its metabolites in 33% of samples; in contrast, only 6% of CULT and WC and 0% of NV samples contained imidacloprid at measur- able concentrations or its metabolites. This suggests that some cover crops may influ- ence leaching of nutrients and pesticides from the vineyard. Maximizing irrigation With increasing competition for water in Missouri between field crops and an- thropogenic needs, it is necessary to find ways to minimize vineyard water use while maintaining wine quality and fruit yield. Arianna Bozzolo et al., of the grape and Wine Institute at the University of Missouri, Columbia, examined rootstock/irrigation interactions and their effects on vine water status, yield and wine quality. To investigate rootstock and irrigation interactions, a vineyard was established in 2008 in Mt. Vernon, Mo., in a full-factorial experiment varying rootstock and irrigation. Chambourcin vines on rootstocks 1103P, SO4, 3309C and self-rooted vines were planted; irrigation treatments were either 1) unirrigated, 2) full replacement of evapotranspiration (ET), or 3) irrigated at 70% of the potential ET (rDI). Soil mois- ture, fruit development, canopy density and yield metrics were monitored, with berry samples taken from véraison to harvest and harvested fruit vinified. In the unirrigated and rDI treatment, the drought decreased mean volumetric soil water content. Mean volumetric soil water content differed among treatments for all the rootstocks. Positive correlations were found between midday leaf water potential (ψ) and the mean volumetric soil water con- tent. Leaf ψ values during the week before harvest indicated varying tolerance of water stress, with own-rooted vines having higher stress for all three different irrigation re- gimes than vines grafted to SO4 rootstock. The unirrigated treatment affected canopy development by reducing the percentage of interior clusters and increasing cluster flux availability and flux symmetry. Treatments affected fruit composition at harvest with differences in berry weight, with SO4/full irrigation producing larger berries than 3309C/fully irrigated and self-rooted vines with no irrigation. Additional differences in fruit composition were observed, with higher TA in fruit from SO4-grafted vines with rDI and unirrigated treatments and lower pH in unirrigated/self-rooted vines. WE Andrew G. Reynolds is professor of bio- logical sciences and viticulture at the Cool Climate Oenology and Viticulture Institute at Brock University in St. Catharines, Ontario. He has written the Wine East col- umn "What's New in Research: Summaries of Current Literature on Grapes and Wine" since 1997. WineEast Natural Corks Champagne Corks Twinline Corks Bartops VISION Synthetic Corks G-Cap® Screw Caps Sales Representatives: Chris & Liz Stamp info@lakewoodcork.com lakewoodcork.com 4024 State Route 14 Watkins Glen, NY 14891 607-535-9252 607-535-6656 Fax PIONEER INNOVATOR PARTNER