Zante Currants broke veraison the last weekend of June — a week to 10 days later than usual for her growers, says Sara Savary.
A PCA with Crop Care Associates, Yountville, Calif., she works in the area between Fresno County and the Sacramento Delta.
As June ended, berries on the Fiesta and Thompson seedless grapes weren’t showing the translucent appearance indicating veraison — that was still a ways off. One of her colleagues is predicting it will occur on July 8, the same as last year.
“I’d rather have it come earlier so we don’t have to fight mildew that late,” she says. “It’s been a long wait for veraison this year.”
She attributes the delay to the weather swings San Joaquin Valley growers experienced through June. The month ended the same way — on June 29, weather was very cool and rainy. Temperatures hit the 100-degree mark over the July 4 holiday weekend.
Despite the challenging weather this spring, she’s seen no disease outbreaks in raisin vineyards. “The pressure is there,” she says. “But, everyone I work with has stayed on top of it pretty well.”
That includes mildew control. Normally, she says, her raisin grape growers spray for mildew every 21 days, dusting vines the last week of the interval unless weather is hot. But, not this season.
“We haven’t stretched the spray interval to the max,” Savary says. “We’re trying to keep it to 14 to 18 days this year because of the weather and the mildew index has been so high.”
Also, breaking with customary practices, her growers are alternating fungicides. Instead of applying a mildew fungus killer each time, they’ve been switching between a mildew material one time and a botrytis product the next.
“Every time we’ve thought we’d get no more botrytis, we’ve hadanother rain shower.”
In early spring, she sprayed some blocks for phomposis. The fungal disease also showed up for the first time in new previously non-phomposis blocks. They will require treatment next spring, in the event of rain then.
Mites have been noticeably absent from the vineyards so far. Usually, her growers see a flush of insects in late May or early June, but this year’s frequent rains have kept mites at bay, she says.
“We made a few early mite sprays in areas where they’re normally a problem. Now, I’m wondering if we should have just waited for them to come up.”
Typically, her growers begin seeing leafhoppers and mealybugs around July 4, but this year she doesn’t expect them to pose any threat until later.
As June ended, her table and wine grape growers were pulling leaves around clusters to promote more air circulation and sunlight to help bring on color in the red varieties. Also, by then most of the bunch tipping of the table grapes had been completed.