North County wine-grape growers are faced with a predicament. To survive one of the worst droughts in California history, they must irrigate. And for many growers, that means tapping into the dwindling Paso Robles groundwater basin.

With little or no rain in sight and conservation a priority, some worry about the long-term health of their crops and are considering the removal of older vines.

“The real issue is the uncertainty,” said Jerry Reaugh, who farms 70 acres of grapes at Sereno Vista Vineyards in Paso Robles. “Are we done with winter? No one knows the answer to that. But if we are done with winter, most people are really scared and don’t know what’s going to happen. How much further will it affect the basin? We’re caught between a diminished resource and trying to keep vineyards alive.”

Grapevine breeders at UC Davis are continuing to develop drought and salt-tolerant rootstocks that can survive in conditions where water is limited. Even so, vines can be stressed to the point where they do not perform well and produce little fruit, growers say.

To make up for the lack of rainfall, some growers have been irrigating their vines in the winter, dormant season, said Mark Battany, viticulture farm adviser with UC Cooperative Extension. Without the pumping of more water than normal, vine growth could be reduced this year, resulting in lower grape yields, he said. Moreover, the dry conditions means greater salt accumulation in the soils, further stressing the vines, Battany said. Grapevines are fairly sensitive to salt content in the soil. The more salt in the soil, the more difficult it is for a plant to extract water from the soil.

“We could not have picked a worse time for a severe drought like this to have occurred on the Central Coast,” he said.

Reducing the crop

Anticipating less water, some growers are pruning earlier and cutting back more, leaving fewer buds to reduce crop load, said Fritz Westover, viticulturist and technical program manager for the Central Coast Vineyard Team, a nonprofit group that promotes sustainable grape growing. They’re also monitoring soil moisture and practicing deficit-irrigation methods, he said.

While it’s a tough decision to pull out a block of vines, some are “kicking around the idea,” Westover said.

“In general, with blocks that are older and declining, there’s more of a reason to pull them out at this point,” he said.

Dana Merrill, owner of Pomar Junction Winery, who also manages North County vineyards through his firm Mesa Vineyard Management, agrees that growers already thinking about removing an older block of vines in the next two years should consider doing it now, and let the ground rest for a while before replanting. Merrill, who says vines can last about 25 years, is considering the move himself.

Most vineyard owners know when they have vines that may be nearing the end of their lifespan and can be removed, he said.

“There comes a time when you can identify a certain block of grapes, and for those thinking they might come out in the next one to three years, maybe you take them out right now,” Merrill said.

Growers are concerned, however, that by the time they get around to replanting, the county may have further tightened restrictions. An existing county ordinance prohibits new or expanded irrigated crop production for two years unless water use can be offset on a 1-1 ratio.

“I think most of us think we’ll go through another year, but if someone says how will it be if it goes another two years … who knows?” Merrill said. “No one knows what’s around the corner. We’re in uncharted territory.”

John Crossland, owner of Vineyard Professional Services, said one of his clients has decided to pull vines from a virus-infected section of the vineyard. His client is waiting to replant that section “until the water situation is less critical,” he said.

“We’ve had no meaningful rainfall in a year,” Crossland said. “So, we’re caught between a rock and a dry spot. I think people are holding off making drastic decisions to see if we do get some rain in February and March.”

Crossland added: “It is rough out here. We’re all concerned and worried, not only from a land stewardship standpoint, but also because incomes are at stake.”

The continuing drought has the potential to be devastating to many growers who depend on the grape harvest for their livelihood, Reaugh said.

“If you’re in that position, you don’t have a lot of choices,” he said. “Maybe you water less and have a shorter crop. It’s like going on unemployment.”

Battany of UC Cooperative Extension isn’t prepared to say just how much of an economic impact the drought could have on growers this year. He’s still holding out hope that Mother Nature will bring a “miracle March.”

“Let’s hold off on making predictions just yet,” he said. “We still have some winter remaining.”

Source - http://www.sanluisobispo.com/

USA - North County growers consider removing old grapevines amid drought

North County wine-grape growers are faced with a predicament. To survive one of the worst droughts in California history, they must irrigate. And for many growers, that means tapping into the dwindling Paso Robles groundwater basin. With little or no rain in sight and conservation a priority, some worry about the long-term health of their crops and are considering the removal of older vines. Anticipating less water, some growers are pruning earlier and cutting back more, leaving fewer buds to reduce crop load.