Mechanical pruning helps reduce labor costs without affecting winegrape quality
By Marni Katz
For California Central Coast viticulturist Gregg Hibbits, the dreary labor picture is written on the wall.
“The future is dark,” says Hibbits, general manager of Mesa Vineyard Management, a full-service vineyard management company that farms 4,000 to 6,000 acres of winegrapes each year. “Either we are not going to have enough people or the people that are available will be much more expensive.”
To help address the challenge, Hibbits is looking to mechanize vineyard operationsparticularly pruning, which is his largest labor cost.
Mesa Vineyard Management machine harvests about 75 percent of its acreage and is moving toward harvesting all of its acreage mechanically.
The next frontier in mechanization is machine pruning, Hibbits says.
“Labor is such a huge component of our vineyard [production costs], and the biggest single labor cost we have is pruning,” Hibbits says.
On the low end, he estimates the company spends about $200 to $300 per acre to prune winegrapes, and that cost has more than doubled in recent years. Per-acre labor pruning costs reach $400 to $500 for more elaborate vineyard canopies and configurations.
For more than a decade, Mesa has been mechanically prepruning—cutting spurs by machine down to a 12-inch cane. Hand crews then come in a month or two later and make the final cuts.
Machine prepruning has significantly reduced the number of workers Mesa needs to prune the vineyard and helps condense that labor-intensive hand-pruning period in January, Hibbits says.
Machines take on hand pruning
Still, it wasn’t enough. Four years ago, the company started looking at full mechanization to further cut costs and decrease its reliance on seasonal labor.
Mesa developed a side-by-side trial in a single vineyard in San Ardo, comparing full mechanical pruning—machine prepruning followed six weeks later by mechanical shoot and crop thinning—with mechanical prepruning and manual follow-up.
The trial has expanded to additional vineyards throughout several Central Coast counties, encompassing different trellis systems and varietals, including merlot, syrah and cabernet.
“We probably mechanically pruned 100 acres this past year, and the plan is to ramp that up to 300 to 400 acres this coming year,” Hibbits says. “There is a real possibility that 75 percent of the stuff we farm, especially in the warmer climates, will go to full mechanical pruning.”