CAPITAL PRESS – TIM HEARDEN – Though labor shortages were the impetus, researchers have found ‘touchless vineyard’ also produces superior wine grapes.
In the heart of the Napa Valley, a vineyard produces fine Cabernet Sauvignon with virtually no help from laborers.
The 40-acre “touchless vineyard” was established by Kaan Kurtural, a University of California Cooperative Extension specialist who has devoted much of his career to improving production efficiency in vineyards as labor shortages have worsened.
The vineyard boasts a canopy that is 65 inches tall, with about 5 feet between plants and a little more than 6 feet between rows.
“Compared to the rest of the vineyards in California, this is densely populated,” Kurtural said.
“We set this up to be a no-touch vineyard,” he said. “All the cultural practices are done by machine.”
The vineyard is mechanically pruned once with a mechanical pruner manufactured by the Fresno-based V-MECH LLC, which Kurtural says cuts the vines without fraying the shoot tips. The pruner is equipped with telemetry and GPS sensors to enable variable management of the vineyard. An array of sensors scans the vineyard as the shoots push out.
“This will give us a vigor index,” Kurtural said. “Then we’ll develop a management strategy to make differences in the vineyard go away and ensure consistent cropping. This is all done by machine.”
The researchers also collect soil and canopy data by machine. If one section of the vineyard is growing out more than the other, the researchers take steps to make the underperforming portion grow as much as the vigorous side, Kurtural said.
The grapes are harvested by a machine that sorts them as it goes, he said.
The vineyard had its first harvest in 2017 and made the wine at the Robert Mondavi Institute at UC-Davis. The wine will be served during a program at the institute in May, Kurtural said.
“It’s a chance for people to taste (wine from) a 100 percent mechanically managed vineyard from the Oakville AVA,” he said. The Oakville AVA, or American Viticulture Area, is one of the most prestigious appellations in the industry, with an average price per ton of grapes nearing $10,000, he said.
Kurtural has been working on production efficiency for the last 10 years. Having received his doctorate in plant biology from Southern Illinois University-Carbondale, he was an associate professor in viticulture and enology at California State University-Fresno before joining the UC-Davis faculty in 2015.
“When I took the job at the University of California, the labor situation started to get worse,” Kurtural said. “If we didn’t have people to prune grapes, we weren’t able to finish pruning. So we said, ‘We are a research station, let’s develop a solution.’”
The research comes as many vintners in California are becoming more automated in response to labor shortages as well as new state wage and overtime laws. Kurtural estimates that about 45 percent of the acreage is pre-pruned by machine, and close to 90 percent is mechanically harvested.
But management of the vines by machines is “the new frontier,” he said.
“We can do all the practices mechanically now,” he said. “There was no economic need to do this previously, but now there is.”
While other areas have moved more quickly toward mechanization, it’s still just taking hold in the Napa region.
“Napa prices are still OK for people to try to do these practices by hand,” Kurtural said. “But when there’s not enough people to do this by hand, now it’s become an economic necessity (to automate).”
When Kurtural started experimenting with vineyard automation 10 years ago, his primary goal was to save growers money in labor costs, he said. But since then, research has shown that grape quality is superior, largely because the tall canopy protects grapes from sun damage, he said. The system also uses less water than others, he said.
These discoveries have caused the popularity of the automation practices to skyrocket, he said.
“It’s quite satisfactory for a researcher to be able to do this,” he said.
Photo: KAAN KRTURAL/UCANR