Issue link: http://read.dmtmag.com/i/437957
w w w. v w m m e d i a . c o m J a n - F e b 2 015 | V I N E YA R D & W I N E RY M A N A G E M E N T 4 1 1 REGULATED DEFICIT IRRIGATION AND PRECISION IRRIGATION "Drip irrigation changed everything," said Napa Val- ley grower Robert Steinhauer, who noted that it provid- ed both water savings and the ability to apply an exact amount of water. Prior to its application in the tree fruit industry in the mid-1980s, then in wine grape vines in the 1990s, flood irrigation, overhead sprinklers and dry farming were the norm on the West Coast. "We benefited from it. Everybody benefited from it," added Doug Gore, executive vice president of wine- making and vineyard operations at Ste. Michelle Wine Estates in Washington. "It removed that mask of veg- etal qualities and made for a purer expression of the varieties, particularly in red grapes." The effects for the industry have been far-reaching. "You can push your harvest date forward in time," said Casey McClellan, founder and winemaker at Seven Hills Winery in Walla Walla, Wash. "You can water to promote more fruitfulness. It's been a huge driver of wine quality." 2 VSP & DIVIDED TRELLIS SYSTEMS "I think everyone has realized that in order to grow truly high-quality fruit and get the sun exposure to the fruit, your canopy needs to be spread a little bit some- how," said Tony Coltrin, director of winemaking and partner at Folio Fine Wine Partners In Napa Valley. Larry Perrine, partner and CEO at Channing Daugh- ters in Bridgehampton, N.Y., noted that VSP was partic- ularly impactful in regions with growing-season rainfall. "It allowed for a trimmer, narrower canopy that can be managed in a very organized and simple way," he said. Timothy Martinson, senior extension associate at New York's Cornell University, agreed. "When they started growing grapes with vertical shoot position- ing and then provided divided training systems like the Scott Henry, that's had an enormous impact on quality and disease management," he said. Martinson said of the Geneva Double Curtain, written about in the 1960s but widely adopted much later, "It allowed an additional 30% of yield for the same vineyard deployment." 3 CANOPY MANAGEMENT IMPROVEMENTS In 1991, Richard Smart published the watershed book, "Sunlight Into Wine: A Handbook for Wine Can- opy Arrangement." The book put forth basic principles for canopy management to improve both yield and wine grape quality with practical examples that could be directly applied in the vineyard. This involved every- thing from shoot thinning to leaf stripping to exposing the canopy to take in more sun. "I could see the turnaround in certain vineyard sites when those principles were applied," confirmed Gary Horner, winemaker at Erath Winery in Dundee, Ore. "It was like night and day in terms of what ended up in the glass." 4 POWDERY MILDEW MANAGEMENT Roger Pearson's work at Cornell on the epidemiol- ogy of powdery mildew and W. Douglas Gubler's work at UC Davis in the mid-1990s on powdery mildew forecasting allowed growers to make more informed decisions about when to spray and when not to spray. "Growers went from feeling like they had to do some- thing every week to going to a more nuanced program," said Cornell's Martinson. The result was a decrease in spray applications and better overall powdery mildew management resulting in an increase in quality. 5 CROP ESTIMATION IMPROVEMENTS In the 1970s, many growers in Oregon and else- where left whatever crop was set out on the vine at bloom. That changed in the late 1980s after research by Steve Price, then at Oregon State University. "That gave us the idea that doing crop estima- tion at lag growth phase, we could use a doubling to give us an idea of what the crop is going to be," said David Adelsheim, proprietor of Adelsheim Winery in Newberg, Ore. This improved estimation allowed for more informed thinning decisions, which significantly increased quality. "In a climate as variable as the Wil- lamette Valley, doing crop estimation and crop thinning, I think, remains the most important thing we do in the vineyard in many respects," he said. 40