Southern Arizona’s wine industry is thriving due to the 16th century Jesuit missionaries who first planted vines here. Some of the original Spanish vines are currently being propagated through the efforts of the staff and volunteers at Mission Garden, located at the base of “A” Mountain, the site of Tucson’s birthplace, an agricultural center for native peoples for over 4,000 years.
Arizona’s wine industry has grown significantly over time and now boasts over 50 vineyards with the majority concentrated in Southern Arizona in Elgin, Sonoita, and Willcox.
A highlight of a Southern Arizona Guide Wine Tour is a stop at Elgins’ Deep Sky Vineyard where owner, Phil Asmundson is often on hand to share with guests what he’s learned from his vineyard in Argentina and how it applies to growing grapes in Arizona. “Our vineyards in Arizona and Argentina share the same latitude and a similar climate, just in different hemispheres,” he said. “Since Malbec vines do well there, we imagined they would thrive here too.” And from his customers’ response, he was right.
His vineyard innovations aren’t just limited to his choice of a new varietal. “The grapevines have a lot to tell us,” Asmundson says, “we just had to figure out ways to listen.” In order to do that, Asmundson has introduced new technologies to his vineyard operations. “We listen in two ways: below the ground and above it.”
Historically, vineyard managers would sample soil periodically using an auger to estimate moisture content. At Deep Sky, a wireless watering sensor software system is employed. Each of the vineyards’ zones sports a sensory probe that collects and reports soil moisture and temperature at various soil depths: 4, 8, 16, 24, 32 and 40 inches. With this new technology, data is collected and analyzed real-time. At Deep Sky, that means every six minutes.
“It’s not uncommon for different varietals to ‘drink’ from different soil depths and at different rates,” Asmundson explains. Paying attention to the levels from which different vines drink, allows growers to water at those depths and not waste water by watering at unnecessary levels.
‘Listening’ above ground occurs with the use of UAVs (Unmanned Aviation Vehicles), more commonly known as drones. According to the University of Missouri Extension natural resources engineer, Kent Shannon, the general use of drone technology in an agricultural setting, allows agronomists to scout for disease, as well as pest and nutrient problems.
However, the newest use of drones, arms them with infrared cameras allowing them to ‘see’ much more than the human eye. Drone flights capture temperature data in real-time and the high-resolution images produced reveal hot spots or cool zones within the vineyard. Viticultur-ists gain insight into what’s happening in the vines’ canopy and may respond almost instantaneously to changes in growing conditions.
Combining data from the below-ground sensing system with above-ground drone-produced data removes the guesswork from vineyard management decisions. Real-time adjustments can be made which not only make it possible to utilize water in the most effective manner possible but also produce optimal grapes. The use of technology takes much of the guesswork out of growing grapes.
There are two periods in grape production where deliberately stressing vines by withholding water is essential. Withholding water during fruit set, usually in late May, produces smaller grapes. This translates into a greater skin-to-pulp ratio and since the skin is where the flavor is, higher ratios produce a more flavorful grape.
The other period to withhold water is during veraison when the grapes begin to ripen. Prior to this point, water has been readily available to the plant to produce its canopy (leaves) which provides shade and shelter for the emerging fruit.
During veraison, it’s important that the vines develop their fruit rather than generating canopy. Limiting water at this time stimulates lignification, a process by which the cluster stems become woody. The hardened stems prevent moisture from being stolen back into the plant from the grapes which restricts further leaf production.
Southern Arizona wine tasting makes a great day outing whether you live here year-round of are just visiting.
For more information about Deep Sky wines go to DeepSkyVineyard.com
For more information about Mission Garden go to Tucsonbirthplace.org
Written by Southern Arizona Guide Contributor, RJ Brenner.
