Issue link: http://winesandvines.uberflip.com/i/66137
TE CHNOL OG Y David Gates, Ridge Vineyards CALIFORNIA Napa Pacific Ocean San Francisco Cupertino NV Ridge Vineyards Monterey Paso Robles CALIFORNIA "I'm comfortable getting the vine through veraison without additional wa- ter," he says. "But I have questions about irrigating between veraison and harvest, so I rely on the sensors." Field work From his cell phone, desk or laptop com- puter, Gates studies the one variable he cannot control: the weather. He prompts the control panel, evaluates water loss from the vine data and analysis panel, updates the vine-management log and records field measurements. The control panel displays a map of the vineyard blocks and color-coded icons to alert him to the conditions of the wired vines. It contains data fields for sending and receiving text messages and record- ing and reviewing recently completed vineyard tasks. From the vine data and analysis panel, he tracks the transpira- tion rate and evaporative demand. The vine management and measurement logs store information about field activities including irrigating, pruning and thinning, plus measurements such as anthocyanin concentration and Brix levels. Data from the sap-flow rate sensors and the weather station record the small- est changes to the transpiration rate of the vines. During the dry summer of 2009, Gates tracked the vapor pressure deficit (VPD) closely. "VPD and sap flow should mirror one another," he explains. "If it is a cloudy day, the sap flow follows the vapor pressure deficit. If not, you need to irrigate." The sap flow fell below a critical threshold when both the VPD and sap- flow rate should have remained high, so Gates irrigated each vine with 20 gallons of water shortly before harvest. "The fact that the vines did not react to the irriga- tion meant that the root zone was filled with enough water to compensate for evaporative demand," he says. The sap-flow rate fell because the atmo- spheric and seasonal demand diminished irrigation requirements for the vines. "It looks like we can dry farm this block most years, allocating water to vineyards that need it," Gates says. Gates can retrieve hourly, daily or month- ly reports that guide irrigation and mainte- nance schedules, present field data, forecast the weather and alert him of changes to the well-being of the vineyard. A watchful eye allows him to irrigate with enough water to avoid dehydrating the grapes, yet not so much that the grapes swell. A weather station from Ranch Systems tracks vineyard climate by sampling the atmosphere and then sending field data to a server that relays the information to Gates' cell phone or computer. via the Internet. Advanced Viticulture, Inc. is operated by Mark Greenspan, Ph.D. P: 707.838.3805 E: info@advancedvit.com W: advancedvit.com Vineyard Management Soil moisture and plant water status monitoring; irrigation management Mineral nutrition management SIS™ soil mapping Vineyard planning and design Wines & Vines JULY 2011 31