Achieving a successful 30-year-old California wine grape vineyard is possible with smart decision making which can reap financial rewards from the longevity.

Five wine grape experts offered input on how to master a 30-year vineyard during a breakout session at the 2014 Unified Wine & Grape Symposium held in Sacramento, Calif. in late January.

A successful long-term wine grape vineyard investment starts with the vine, says James Stamp, principal, Stamp Associates Professional Viticulture Services, Sebastopol, Calif.

“The vine is the most important part of the vineyard,” Stamp said. “It sometimes gets left behind when planning a new vineyard.”

Vine quality and cleanliness are paramount, Stamp says. Yet his greatest concern about available vines today is the virus status of current materials.

Over the last year, Stamp says some California Department of Food and Agriculture (CDFA)-certified nursery stock were found infected with red blotch virus and leafroll associated virus 3 which reduce the brix (sugar) level in wine grapes.

Stamp says CDFA certification is supposed to provide growers with the confidence that they are buying good plant material.

“The CDFA certification program does not work properly,” Stamp said. “You have to go to the trouble to test your own plant materials to determine its virus status.”

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Beyond the virus issue, Stamp’s second largest concern about vines is the physical quality of the vine. A plant with a high level of fungal pathogens is more likely to create poor graft unions or poor root systems which can limit the vine’s productive life expectancy.

Stamp says vines should be delivered on time to the grower with the requested rootstock and the exact quantity ordered.

If working with a nursery for vines, nursery sanitation is important. Stamp says work with a nursery which practices good sanitation. An operation with less dust reduces pathogen transfer through the air.

“Cleanliness is next to Godliness. If you see a nursery that looks clean then chances are the vines will be better quality,” Stamp concluded.

Field budding and grafting

Another panelist was Daniel Robledo, a Sebastopol viticulture consultant with 40 years of experience in field budding and grafting vines. He advocated timeliness and cleanliness in budding and grafting as a component of a successful vineyard.

“When a vineyard is grafted over and either the vineyard or budwood have a virus species, there will be problems. If there are multiple virus species, it will get even worse,” Robledo said.

This can reduce the life expectancy of the vineyard.

Robledo offered four points to help achieve successful field budding and grafting. First, use quality, clean budwood. Second, know the status of the vineyard for budding and grafting. Be aware of viruses and pests vectors in the vineyard.

Third, choose a good time to bud and graft.

“If you top graft in the fall you will have 100 percent failure,” Robledo said. “There is not enough time for the grafts to establish, grow, and become cold hearty. Timeliness is very important.”

And fourth, there is no guarantee of vineyard success with budding and grafting due to weather – rain, plus cold and hot spells.

Robledo said, “If someone guarantees 100 percent success, don’t believe them.”

The key is to use clean stock and be timely. Hire a consultant if necessary.

John Crossland of Vineyard Professional Services manages about 3,000 acres in the Paso Robles, Calif. area where he specializes in vineyard site preparation.

“Can we (successfully) develop a 30-year vineyard,” Crossland asked. “I say definitely. It’s been done before - it can be done again.”

He offered a list of vine challenges called “20 Shades of Vine Stress” - common mistakes made in vineyard site preparation and establishment.

One mistake is the well-intentioned but inappropriate rootstock choice for a given site. Another is over cropping where too much is expected of a vine for a specific area. This can cause shorter shoots, prolonged ripening, and difficulty in the vine storing  carbohydrates over the winter months to help set the next crop.

Also beware of incorrect vine spacing which can over burden vines. Too much distance in the vine row can push the vine too much.

Vine disease was discussed by Martin Mochizuki, owner of Mochizuki and Associates, Inc., Napa, Calif., including avoiding and coping with degenerative diseases - Eutypa dieback, bot canker, leafroll, and red blotch.

In many cases, symptoms of Eutypa and bot canker may not show up until years 11-12 of the vineyard and then growers typically start treatment. Waiting this long makes it harder to control the problems and much more expensive to remedy.

“For Eutypa and bot canker, it’s important to start (treatment) early in the life of the vine,” Mochizuki said. “By year three, start thinking about making big cuts.”

Late pruning and double pruning can help reduce the infection rate. Use wound protectants whenever possible.

“Which vines should be protected,” Mochizuki quizzed the group. His response, “Only the vines you want to keep. Cut out existing infection.”

Grapes and the competition

The final speaker was Mark Couchman with Silverado Premium Properties. The company manages 20,000 acres of wine grapes and vineyards in California; principally along the coastal zones, plus in the San Joaquin Valley.

Couchman discussed the profitability of wine grapes and other crops that compete for farm ground in California, including tree nuts, berries, and vegetables. He says nuts, berries, and veggies can currently generate higher financial returns for growers than wine grapes.

“Wine grapes are on the lower end of the (financial) return spectrum but are also on the lower end of the risk spectrum,” Couchman explained. “If you build a good, high-quality vineyard, you should get good reasonable returns, and hopefully some nice wine to go with it.”

Yet, he says wine grapes have one major, and timely, benefit over the aforementioned crops.

“Wine grapes generally require less water. Water is less available and more expensive by the minute,” Couchman concluded.

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