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p r a c t i c a l w i n e r y & v i n e ya r d J U n e 2 0 1 4 53 g r a p e g r o w i n g 58 Nighttime plant water loss — Unseen process for local/global water footprint and water balance estimates in grapevines By Sigfredo Fuentes, Roberta De Bei and Stephen Tyerman 64 Closure selection and pH influence on red wine color and tannin during bottle aging By Jacqui McRae and Paul Smith 67 Branding strategies in agricultural commodities By Katja Loeffelholz 70 Branding your small vineyard By Todd Newhouse T E C H N I C A L R E S O U R C E F O R G R O W E R S & W I N E R I E S practicalwinerylibrary.com Access Practical Winery & Vineyard article archives online. Determining impact of hand or machine leaf removal on fruit quality Dr. Patty Skinkis, associate professor and viticulture extension specialist, Oregon State University, Corvallis, Ore. BY All Photos by PAtty skinkis O ur vision of the 2013 growing season was one of easy suc- cess in July, two months before harvest. There was limited rain and advanced grape development across the state, something that had been rare in recent years. However, September proved challeng- ing due to shifts in weather that led to berry cracking and increased fruit rots across much of western Oregon. Ques- tions poured in from industry profession- als seeking information about Botrytis bunch rot management and more. Most growers were already using proper pre- ventative measures: appropriately timed fungicide applications combined with judicious cluster-zone leaf removal. As harvest neared and rains began to fall, heightened concern about fungicide use and pre-harvest intervals (PHI) developed, leading to discussions about cultural management techniques such as leaf removal and culling damaged fruit. Leaf removal has been well-studied worldwide by numerous researchers (including work conducted in my pro- gram at Oregon State University). Those studies varied from the impacts of leaf removal on vine growth to impacts on fruit ripening, berry composition, wine quality and disease potential. A trial that compared manual and mechanical leaf removal was of particu- lar interest to the industry in 2013 for sev- eral reasons: sunburn/heat damage, disease management and labor short- ages. Many growers in Oregon have shifted to mechanical leaf removal dur- ing the past few years because it can reduce canopy management costs. We estimate hand leaf removal to cost approximately $270 per acre on average density vineyards (1,245 vines per acre). 1 Mechanical leaf removal costs of $25 per acre compared to $130 per acre for hand leaf removal has been reported in Califor- nia's Central Coast vineyards with vine densities ranging from 908 to 1,089 vines per acre. 3 Perceived drawbacks to mechanical leaf removal include damage to clusters, reduced precision compared to hand- removal and the potential for leaves to remain lodged in dense canopies. Devel- opment of new leaf-removal technology and equipment has reduced many of these concerns. However, applied research is needed to determine how mechanical leaf removal affects key aspects of vineyard produc- tion so that growers can make informed A