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S M A R T V I T I C U L T U R E by Dr. Richard Smart Thanks to Mark Kliewer for invaluable research I nternational viticultural researchers and grape and wine producers from the American wine sector attended a grapevine canopy management symposium at the University of California, Davis, on July 16, 2009. This symposium was dedicated to Professor Emeritus Mark Kliewer of UC Davis, who was a staff member there for more than 30 years and a pioneer in grapevine canopy management research in California. Professor Kliewer organized the first international symposium on grapevine canopy management, and held in California in August 1986, attended by more than 500 people. Many of the speakers at that first symposium contributed to the second symposium 23 years later. During his career, Kliewer made significant contributions to the California wine industry through his research on canopy management. Many of the present-day grapeproduction systems can be traced to his research. He trained more than 50 graduate students, who are a continuing testament to his enthusiasm for viticultural research. This symposium was organized by Dr. Nick Dokoozlian, one of Kliewer's former graduate students and currently vice president of Viticulture for E&J Gallo Winery, Modesto, Calif., and Jim Wolpert of the Department of Viticulture & Enology, at UC Davis. "It is difficult for me to imagine a viticulturist that has had a more profound impact on modern California grape production than Dr. Kliewer, professor emeritus at UC Davis," says Dokoozlian. "Kliewer trained a generation of viticulturists that currently influences grape and wine production in every major growing region in the world. "A prolific researcher, he also laid the foundation of knowledge necessary to establish many of the standard vineyard development and cultural practices used today, including nitrogen and potassium fertilization, irrigation, vine spacing, training/trellising systems and canopy management. It is nearly impossible to visit a vineyard today, in California or many other parts of the world, which has not been directly influenced by Kliewer's work. This text reprinted from first publication: Nov./Dec. 2009. "As a young graduate student, I found working alongside Kliewer in the vineyard quite challenging. He always volunteered for the most physically demanding job during harvest, and worked both quickly and methodically. His office door was always open to students and others requesting his assistance and advice. Hard working, dedicated, kind and humble, Kliewer's scientific accomplishments were overshadowed only by his outstanding personal character. It was a great privilege to study and work under his guidance, and I am very proud to call Mark Kliewer my mentor and friend." Dr. Pat Bowen (Canadian viticultural scientist and a former Kliewer student), began the symposium, reviewing Kliewer's research contribution. His early work was in temperature-controlled growth cabinets where he showed the significance of light and temperature in the formation of organic and amino acids, sugars and anthocyanins. By the 1980s, research conducted by Dr. Nelson Shaulis (Cornell University, Geneva, NY), in the eastern U.S. and European and Australian researchers demonstrated that the light and temperature environment of grape berries and leaves have an important impact on fruit composition and wine quality. This began a new period of research activity for Kliewer and his students, investigating aspects of vine physiology and canopy management in California. Since the first symposium, the science has improved considerably. Dr. Hans Schultz, (director of the Geisenheim Research Institute, Geisenheim, Germany and also a graduate of UC Davis), presented results obtained from computer modeling of grapevine canopies. Using this approach, grapevine physiology can be simulated with a computer, allowing for evaluation of a wide range of inputs like climate and canopy architecture. An Australian perspective on canopy management was presented by Dr. Peter Clingeleffer (CSIRO Plant Industry, Merbein, Victoria, Australia) who emphasized the important contributions of vineyard mechanization and minimal pruning. Dr. Alan Lakso (professor and researcher at Cornell University's Geneva Experiment Station) was also a Kliewer graduate student. He presented intriguing results, showing the impact of the link between shoot growth rates and canopy microclimate on the concentration of methoxypyrazines in Cabernet Franc grapes in upstate New York. Excessive green characters (sometimes called "veggie") are common in cool, wet climates like New York. It has long been known that fruit shading contributes to such undesirable character, but research by Lakso and his colleagues has shown that actively growing shoots in late July also contribute to these negative characters in grapes and wine. Dr. Alain Carbonneau (professor of viticulture at Montpellier [France] SupAgro, and current president of GiESCO [Group of International Experts of Vitivinicultural Systems for CoOperation]) presented a description of grapevine trellis systems in use around the world and showed how the wide range of grapevine canopy types can be analyzed and modeled. In particular, a few simple measurements can tell much about how vineyards will perform. Dokoozlian reviewed the past 20 years of canopy management practices in California, including trellising and variation in tractor row and vine spacing. Contrary to popular opinion, he reported that research has shown that decreasing spacing in the vine row creates greater canopy density, an effect greater than inter-vine competition. Other studies show that narrow tractor rows, a practice often proposed for the purpose of improving wine quality, also lead to increased yield. Professor Mark Kliewer pr actica l win ery & vin eya r d JANUARY 20 14 65