In early March, crews of Pacific Vineyard Company, which manages wine grape vineyards in the Edna Valley near San Luis Obispo, Calif., completed the hand pruning work they began the first of the year.
Most of the vines, including Chardonnay and Pinot Noir, the valley’s primary varieties, are cane pruned.
“This gives us more consistent production and more options later in the season for thinning to maintain quality,” says Erin Amaral, the company’s viticulturist and PCA. “We spur prune varieties with larger clusters, mainly Syrah, to better separate clusters and provide better air movement to help reduce any disease problems and to increase sunlight for better ripening.”
She began seeing bud break the third week of February. That follows very warm weather in January, which turned more seasonably colder last month.
Frost is always a threat to early budding vines in the area. Frost alarms are set to go off when the temperature drops to 35 degrees, allowing crews time to get the wind machines started. Plans called for starting frost control the week of March 6.
“It’s been cold enough at night that we’ve seen a little frostbite on new pushing buds on hilltops,” Amaral says. “But, it’s nothing to be concerned about at this point.”
Just as new buds begin to push, she plans an early season application of JMS Sylet oil to help protect vines from powdery mildew. Last year’s unusually cool season contributed to heavy pressure from the fungal disease in the valley.
“We think a lot of spores are still in the vineyard,” Amaral says. “The first powdery mildew spray of the season is the most important, particularly so this year to clean up last year’s spores. If we can get a jump on the disease before the shoots grow out too far, we’ll be ahead of the game by reducing inoculum in the fields.
Following that spray, she’ll rotate among other fungicides, using different chemistries to continue fighting the disease through veraison. “Because we expect more spores than normal this year, we’ll be very proactive,” Amaral says. “We’ll probably add a few more fungicide sprays than normal because we started earlier.”
Rainfall amounts have been decent the last few winters, she says. “Our heavy clay soils have a great ability to retain water, allowing us to save on irrigation costs. The water bank should carry the vines through most of the spring. We won’t have to start irrigating until much later.”
Timely rains in December also helped improve early-season weed control. A series of storms set the preemergence herbicides.
“All the vines have very nice, clean berms under them right now,” she says.