A week after unwanted rains began to hit vineyards in Sonoma County, some grape growers are reporting significant signs of damage to the county's $400 million crop.
For many growers, it's too early to quantify just how much of the crop has fallen victim to the bunch rot called botrytis. Most are too busy attempting to control the damage Mother Nature wrought — harvesting if the sugar levels are right, spraying fungicide on grapes that need more ripening time, and pulling leaves out of canopies to help eventual sunshine and winds dry out the clusters.
“It's taken a toll on everyone, on the grapes as well as everybody's outlook,” said Saralee McClelland Kunde, owner of Saralee's Vineyard in the Russian River Valley. “There's a lot of botrytis out there. We're all seeing it.”
Rainy weather returned to Sonoma County on Monday after a three-day dry interlude. Monday's storm dropped less than a quarter-inch of rain on most parts of Santa Rosa, according to the National Weather Service. Forecasters expect a few showers early Tuesday morning, and then warm, dry weather until the weekend. But Saturday may bring another bout of rain.
“It's hard to say what it's going to be like then,” said Chris Stumpf, meteorologist. “I imagine there will probably be some rain there Saturday afternoon.”
The botrytis problem is becoming serious for some growers in the Russian River Valley, where the cooler climate delayed ripening of chardonnay grapes. Glenn Alexander, owner of Bacchus Vineyard Management, said he lost 50 percent of one zinfandel vineyard to botrytis, and lost 15 to 30 percent of his chardonnay grapes to the fungus.
“It's going to be worse in a couple of days,” Alexander said. “Its growth rate is exponential.”
The rot problems caused by the rain are hitting growers twice, Alexander said. First, growers have to pay for crews to cut leaves out of the canopies, to expose the fruit to the drying sunlight and wind. And then, the grapes that are infected with botrytis are unusable, so there is a smaller crop to harvest and sell.