Issue link: http://winesandvines.uberflip.com/i/107279
GRAPEGROWING costs to the same level as those incurred with complete vineyard redevelopment. The decision to replant depends on the age of the damaged vineyard and on market demands (i.e. whether the variety is still in demand). W&V: You've developed a mathematical model that growers can use to make practical decisions when cold weather is expected. Please explain how that works. Keller: As a service to growers that is partly funded by industry, my lab routinely monitors the level of cold hardiness each winter from October through March or April. We do this because hardiness varies throughout the dormant season. Vines become hardier when they acclimate to colder temperatures in fall and lose hardiness when they de-acclimate to get ready for bud break in spring. But at any time, they also respond to fluctuations in temperature: When it's cold they gain hardiness, and when it's warm they lose some of it again, even in mid-winter. So we measure, weekly or biweekly, the changing hardiness levels of the buds, bark and wood of about 20 varieties and post the current values on our website.1 The growers follow these trends to decide whether to run their wind machines for some or all varieties. Selecting varieties for climate A lthough Chardonnay and Cabernet Sauvignon dominate the vineyard landscape in eastern Washington, Washington State University's Markus Keller thinks there are other grape varieties that would do well in the region, given its growing conditions. "Personally, I would like to see Malbec," he says, because it's as hardy as Merlot and "does very well in a similarly dry climate, in Mendoza, Argentina." Another grape he cites is Cabernet Franc. He says it is "one of the hardiest European winegrapes, but it is not fashionable, clearly losing out to Cabernet Sauvignon." Finally, he says, "Nebbiolo seems to be at least as hardy as the widely planted Syrah and, from a quality perspective, definitely deserves a go." L.D. This is great, but it makes me nervous when growers in Colorado or British Columbia tell me they use our website to guide their decisions regarding frost or freeze protection. Their local conditions might be very different from the ones where we collect our samples. This is why we have developed a mathematical model that takes advantage of our long-term dataset (more than 20 years of measurements) to estimate the hardiness level based on local temperatures on a daily basis. This is about as real-time as it gets and can be done using any weather station that collects daily maximum and minimum temperatures. The model now runs on WSU's automated weather station network called AgWeatherNet2, plotting the progress of bud hardiness for 23 varieties for any of the network's 138 weather stations. The advantage here is that a grower can use the station that is closest to his or her vineyard rather than just guessing from our Prosser Try Before you Buy – conTacT your local rep Today FREE TRIAL OF OUR NEW TANKJET ® 55 BARREL CLEANER Superior Spray. SeriouS reSultS. TankJet 55 barrel cleaner for cleaning barrels up to 5' (1.5 m) in dia. 60 W in es & V i ne s F E B R UARY 20 13 Take advantage of this risk-free offer to try our new TankJet 55 barrel cleaner in your winery. You'll experience benefits like these: • owerfulcleaningusinglowflow P rates to prevent toast removal and reduce water and chemical use • astcycletimesenablecleaning F of multiple barrels in minutes • urableconstructionanduse D of wear-resistant materials extend service life • asytouse–compatiblewith E most pumps and pressure washers Try the TankJet 55 today! call 1-800-95-Spray or visit TankJet.com.