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Wine Industry

With vineyard labor scarce, Napa growers warm up to machines

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Machines in the vineyards

Researchers at the UC Davis Oakville Experimental Station have developed a "no-touch" vineyard where machines, such as this shoot thinner, do all the manual work. 

One warm June morning a rumble began at Hudson Vineyards. Dull at first, the low automatic hum grew, pulsing louder and closer as Kelly MacLeod searched the rolling rows of the Carneros ranch for its source. Peering down a corridor of bright emerald Chardonnay, she finally spied a single sunhat.

The hat crested the hill, a pair of sunglasses and a masked face beneath it, all carried on the steely drone of a red tractor over the hill and down the row of vines. Off to one side, a flurry of green spouted from a box on an outstretched metal arm that grazed the vines facing the mid-morning sun.

The machine reached the end of the row and rolled on, leaving behind a trail of cut leaves and yesterday’s way of farming in Napa Valley.

“Like all of California, we are having a labor shortage,” said MacLeod, who is director of vineyard operations at Hudson Vineyards. “And as we want to continue to grow grapes and push to grow better grapes every year, we found that this allows us to nail the timing.”

In leafing, where vine canopies are thinned to expose growing berries to sunlight, that timing is vital. The work must be done before the days become too hot, but not before flowering and setting of the fruit is complete. Berries need to be slightly smaller than pea-sized and clusters must grow to a size where the machine won’t take them out along with the leaves as it goes by.

For Chardonnay, which makes up more than half of Hudson’s 200 acres of vines, the time is now, while red varietals won’t be ready for another week or two. Yet the years-long lack of available labor has made it impractical to have crews do all of the leafing by hand in a timely way, MacLeod said.

In turn, this will be the fourth growing season the ranch has used a machine instead of handwork to do the first round of leafing for its vines.

As it goes along, the leafer grazes the vines near their fruit zone, sucking and cutting the layer of leaves above the berries and opening spaces in the canopy for gentle morning light to filter through. The ranch uses cane pruning, MacLeod said, with vines in some blocks trained using more of an arch than others. The leafer can be set to trim higher or lower depending on the height of the fruit clusters on each arch, taking off only what is in the fruit zone and nothing much higher.

The process allows for the basics of spray penetration, early sunlight and air circulation at the right time in the growing season, leaving the more specific handwork for a crew of a dozen workers that will comb through the rows later. At Hudson, which sells its fruit to 22 contracting wineries, the amount of leafing also depends on their clients’ flavor preferences.

Machines in the vineyards 2

A mechanical shoot thinner moves through the "no-touch" vineyard at the UC Davis Oakville Experimental Station. 

The crew will do a second pass by hand to the specifications of the winery buying the fruit, though some winemakers choose to have only the machine do the leafing, satisfied with the dappled light it provides after one pass.

MacLeod approached a row thick with leaves.

The winemaker who sources fruit from that portion of vineyard prefers riper flavors in their Chardonnay, she said, making them Hudson’s “most extreme leafer.” She began to yank leaves from the vines by hand. A few moments passed as she hastily plucked, making only a slight dent in the canopy.

“You can see the time difference between how long that just took me,” she said, as the hum of the tractor began to grow again, farther down among the rows.

Labor shortages plague wine industry

The years-long labor shortage affecting the whole of California agriculture has left the statewide wine industry, Napa included, struggling to maintain high-quality farming practices without the support of an ample workforce.

At a business seminar for grape growers here in May, Dr. Giovanni Peri, chair of the Department of Economics at the University of California, Davis, shared the results of a 2017 survey of local vineyard companies regarding the shortage. Responding companies represented more than half of the vineyard acreage in Napa.

Asked whether they had difficulty hiring the amount of workers needed, 65 percent of responding Napa firms said they had, while 87 percent of the surveyed vineyard management companies, which employ the most workers, reported experiencing a shortage in 2017. Peri noted the results were similar to the prior year’s numbers as well.

Based on companies’ responses, estimates from the survey suggest the overall grape growing workforce in Napa was short by more than 1,200 workers last year.

Driven in part by the federal crackdown on immigration, an improving economy in Mexico and the allure of higher-paying construction jobs for potential farmworkers, the wine industry’s vineyard labor shortage has pushed growers here to hire more women for their crews, shift the timing of activities throughout the growing season and slowly embrace the use of machines for vineyard work formerly done by hand.

But while mechanization has already become commonplace in many other grape growing regions throughout the state, and in other countries around the world, MacLeod acknowledged there has been an aversion among Napa growers to using machine labor in their vineyards.

“But I would say that, more accurately, what I’ve seen now …” she trailed off as the leafer came into view again, whirring back the way it came several rows down. As the metallic crunch of leaves subsided, she finished the thought. “What I’ve seen is it’s an adjustment period.”

When Hudson first purchased its leafing machine, clients were concerned, she said, and came to see the work firsthand. After witnessing its timeliness, coupled with the follow-up from the crews, the winemakers were sold on it, she said.

“Now not a single one of our clients that we sell grapes to even blinks an eye. It is the reality of farming now.”

The company needs only one machine for the entire 200 acres of vineyard and, once begun, the process can be completed within a couple of weeks. The team at Hudson hired a vineyard management company to help them sift through a variety of leafing machines, doing test runs in their vineyards with a range of models before landing on the one used today.

“A lot of mechanization is kind of finding what works on your site and your operation,” MacLeod said.

As it happens, for growers who may be looking to glean more about a move toward mechanization, perhaps the best living example exists today in Oakville.

UC Davis’ ‘no-touch’ vineyard

On a recent morning at the UC Davis Oakville Experimental Station, extension specialist Dr. Kaan Kurtural walked along the edge of an especially tall block of Cabernet Sauvignon.

Planted in 2016, the block hosts 1,340 vines and produces roughly 15 to 18 pounds of fruit per vine. “So it’ll be yielding quite nice,” Kurtural said as he walked down the 62-inch tall rows.

Far more notable than the vineyard’s fruit, however, is how it gets farmed.

“There are no hand practices out here,” said Kurtural. “Everything is done by machine.”

From spraying to pruning to canopy management, all the way through harvest, the vineyard is essentially “no-touch.” The processes can all be carried out with the same machine, its frame fitted with different heads depending on the work needed.

As Kurtural walked through the rows, the vines were being watered by an irrigation system directed by sensors in the vineyard.

In all, he said, the cost to manage the vineyard comes to about 7 cents a vine.

“This is as cheap as it gets I think.”

The block’s design also factors into the equation, with vines spaced 1.5 meters by 2 meters apart to achieve the best light relations on top of the rows.

“So the idea is that since these are sprawling canopies, once this fruit starts filling up, the canopy pulls itself down and you get the sunlight in the middle,” Kurtural explained. He contends that the light relations in the mechanically-farmed systems are superior to those of a traditional system. “So we’re getting much better quality and consistent cropping,” he said.

In hand-pruned vineyards, he and his colleagues have found that the more space that is opened, the more quickly the spurs will close up. “The quality actually gets worse. Then you have to come back and remove a lot of clusters to get them to catch up,” he said. “So you’re able to avoid that by tricking the plant into growing upright.”

This growing season will mark the second year grapes from the Oakville vineyard have been used to produce wine at the university’s winemaking facility on its Davis campus. There, many of the winemaking processes have become automated as well, a shift that has been making its way to wineries here in recent years.

But how does wine from a mechanically farmed vineyard taste?

“No one can tell until we tell them what it is,” Kurtural said. “Then they say, ‘Oh, I can taste it now.’ But, you know, that’s classic.”

While he’s noticed the use of machines in Napa vineyards becoming more widespread in recent years, in other grape growing regions throughout the state, practices like hedging, leafing and shoot thinning have been completely mechanized for some time, he said. He estimates that approximately 90 percent of California acreage is mechanically picked today.

“I mean To Kalon will probably be the last one to adopt,” he said, referring to what is perhaps Napa’s most famed vineyard, which sits just adjacent to the ‘no-touch’ site. “Because there’s no economic incentive. Grapes here are at least $11,000 a ton. So they can still afford to do it if they can get the labor.”

But, Kurtural said, “This is a statement in the middle of To Kalon. Everyone stops here and sees what this is. People come all the way from Temecula to see this system, because it’s quite novel. We can automate everything here.”

Asked why grape growers might hesitate in adopting mechanical practices, he shrugged. “It doesn’t look romantic? I don’t see any other reason.”

Though as the years-long labor shortage persists with no signs of abating, grape growers throughout Napa are increasingly planning for a future where machines will become even more present in the vineyards.

At Hudson, new blocks have been planned and planted with mechanical harvesting in mind. The company planted its first block of Cabernet Sauvignon last year in a bid to diversify the ranch’s production, MacLeod said. The first crop is expected in 2019.

The team consulted with vineyard management companies that already use machine harvesting, she said, learning how to set up the block to be picked by machine.

In planting for mechanical harvesting, tall thin highway stakes are chosen for their efficiency, as the machine harvester works by opening and closing around the stakes, then rolling down the rows while it shakes the trellises.

The harvesters knock grapes free of their stems, which remain on the vine while bins are filled only with grapes. The result is ultimately far less work in the winery, MacLeod said, as destemming no longer needs to be done.

But while it works effectively for red varietals, the process becomes difficult for thinner-skinned white grapes, she added, as broken berries can lead to concerns about oxidation.

“That’s why we haven’t quite fully embraced it yet, because we’re trying to figure out how you do it,” she said. “I think if we were a predominantly red ranch we would be already embracing that technology.”

As the ranch continues to move toward its first mechanical harvest and MacLeod considers the larger sea change in Napa, she’s optimistic. “I think it’s all positive. It’s a positive adaptation to a shift for us. I think these might not have been things we (would have) explored 10 or 15 years ago.”

“The reality is we’re all going to just have to open our minds to it. Plenty of other countries are doing it with great success and we absolutely can too. We just need to learn the process.”

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Wine Reporter / Copy Editor

Henry Lutz covers the local wine industry. He has been a reporter and copy editor for the Register since 2016.