This trunk scrubber of the vMech system is used by Ste. Michelle Wine Estates to control suckers. The device looks similar to a weed whacker with multiple strings.
PHOTOS COURTSY OF STE. MICHELLE WINE ESTATES
Technology has eliminated the need for hand labor for nearly all vineyard tasks. But while new technology can save grape growers hundreds of dollars per acre, winemakers’ perceptions that grapes from mechanized vineyards are inferior to vines grown only with hand care have made for a slow transition.
Washington State’s biggest wine producer, Ste. Michelle Wine Estates, uses mechanization in many of its vineyards that produce grapes for low- to mid-tier wines. For Ste. Michelle, mechanization is a way to manage costs and improve efficiency, says Mike Means, director of operations. “For us, it’s about dollars and cents and the types of wine style tiers that the fruit is going into,” he said, adding that it’s not so much about availability or quality of labor.
However, other grape growers have had difficulty finding workers to do tasks like leaf removal because the timing comes when Northwest cherries and blueberries are also being harvested.
Keith Oliver, production manager of Olsen Brothers, Inc., in Prosser, Washington, says they purchased their first leafing machine last year because of labor shortages. “We never thought it was cost effective in the past to do leaf stripping with a machine,” he said. “But we can’t find enough labor when it’s time to do leafing. We’ll probably be buying another machine soon.”
Ste. Michelle uses the vMech system for its vineyard mechanization, Means told members of the Washington State Grape Society at their last annual meeting. vMech is based on a systems approach to mechanization conceived by Justin Morris at the University of Arkansas and further developed by OxBo International. The vMech quick-connect implements (for pruning, shoot thinning, sucker control, spraying, mowing, and more) can be either mounted on a tractor or a tractor-driven trailer platform. The vMech system comes in single- or double-row configurations.
Several other equipment manufacturers also offer a full line of vineyard maintenance tools.
One of the biggest considerations when mechanizing vineyard tasks is trellis condition and design. “Your trellis has a big impact on the effectiveness of these machines,” said Means, adding that vertical trellis systems, such as the vertical shoot position, work best. Trellis systems with cross arms can be a problem for mechanization. Some of the new implements use sensors to detect trellis stakes and allow the machine to go around the stake and avoid hitting it.
New pruning implements—some with vertical and horizontal saw blades—are more precise than the older-style hedgers and can prune to within two inches of the cordon, eliminating the need to touch up by hand.
Ste. Michelle is able to leave spurs with one to four buds with the vMech mechanical pruner. “We can get down pretty tight on the number of spurs left,” Means said.
Ste. Michelle mechanically prunes more than 270 acres in Paterson, some of which have been mechanically pruned since the 1980s. Early on, taste panels found little differences between wines made from grapes pruned traditionally (using pneumatic pruners) and mechanically pruned vines, he said. Pneumatic pruners are used in many vineyards and have made pruning easier, but the method still uses hand labor.
Kiona Vineyards’s Scott Williams bought a prepruner implement in 2004 to use on his Red Mountain vineyards that had significant bud damage from cold temperatures. He paid for the machine in the first year, and continued to use the pruner until last year when a cane-boring beetle was discovered in the vines. “The pest didn’t seem to cause economic damage, but it scared me, so we hand pruned all of the vines last year.”
Mechanical leaf removal implements were a hot-selling item last year, according to Grant DeVries of Vine Tech Equipment, Prosser, which sold a record 17 leaf removal implements.
Timing is very important when using a leafing machine, Williams stressed. “If done too early and the grapes are too small, you can suck the clusters and berries into the roller that is pulling the leaves from the canopy,” he said. “If done too late, you can skin up the grapes, and they have potential to crack later on. In vigorous vineyards, the leaves may regrow by veraison, defeating the purpose of leafing.”
Time of day can also be critical when using leafing machines. Leaf turgidity is needed for the pulsating air machine, and they often lack turgidity on warm afternoons. With the suck-and-pluck type of machine, the operator has more hours in the day to run the equipment, Means noted.
He advised growers to move trellis wires out of the way several days before running a leafing machine to allow the leaves to reorient to the sun so the machine works more effectively.
The vMech system has a flexible, rubber flapper that removes shoots for shoot thinning. Means credits the shoot thinner for reducing input costs in Ste. Michelle’s lower- to mid-tier vineyards. The machine is most effective with shoots that are shorter than six inches.
“It’s important that growers do shoot counts prior to and immediately following use of the shoot thinner to make sure things are adjusted at the proper speed and the right number of shoots are removed,” he said. “We did a lot of Cabernet Sauvignon with the shoot thinner; at harvest, we were getting 24 Brix and around six tons per acre.”
Ste. Michelle uses a trunk scrubber, also available with the vMech system, to remove suckers at the trunk base with a plastic brush tool. It is then followed with an application of the herbicide Aim (carfentrazone-ethyl). A sprayer with an electric eye is used to selectively spray only green vegetation.
Means has found that time of day also matters when going after suckers. Shoots snap off more easily in the morning than they do in the afternoon when temperatures are warmer. And, he warned growers to watch out for drip hose line when using the sucker brushes. Emitters can get knocked off by the brushes and hose line wrapped around the tool if the operator is not careful.