Even though his 120-acre raisin grape vineyard got off to a weather-delayed start this year, Bob Brar, Fowler, Calif., is pleased with the condition of Thompson seedless vines and grapes.
This year’s bloom was spotty, he says, but it was an improvement over last year’s light bloom — plus, his bunch count is up about 5 percent compared to 2009.
“This year’s crop looks better than last year’s,” says Brar. Favorable weather since spring, including some good rains, has helped. “We’ve had a few, short heat waves this year with temperatures above 100 degrees.”
The heat didn’t settle over the valley until well into July this year; in 2009, it got hotter sooner.
Brar has been growing raisin grapes for 30 years. His drip-irrigated vineyard features a double-wire trellis system with the wires spaced vertically 14 inches apart, hand harvesting and single-tray drying.
This year, populations of his three major pests — leafroller, leafhopper and spider mites — are down.
Not surprisingly, with the long, cool spring, his vines have a more powdery mildew than usual. The fungal disease began showing up in March.
Phomopsis has also required treatment. Following his customary practice, he treats both diseases at the same time, applying liquid sulfur for the mildew, and copper for phomopsis.
Brar makes the first application when the new shoots are 1 to 2 inches long, and makes a second treatment about 2 to 2½ weeks later, when shoots have lengthened to 8 to 10 inches. Once the shoots reach 12 to 14 inches, he stops the copper treatment and switches to a dry sulfur application and continues dusting once a week as long as it’s needed.
“When spraying, the outer leaves can block the spray from reaching inner leaves,” Brar says. “But with dusting, we get much better coverage because the material gets into and around all the leaves.”
Last year, he made his last dust application April 26. This year, he dusted a total of 10 times, applying the final treatment in the second week of July.
He expects to begin picking his grapes around Labor Day.
“When bloom started this year, we were running about 10 days to 2 weeks behind normal,” he says. “Usually, the berries start to soften around the Fourth of July, but this year that began on July 10. So, now, we’re only about a week later than usual. If temperatures stay between 90 and 100 degrees the rest of this month, the crop should catch up.”
“By Labor Day, the sugar should be at 20 degrees to 21 degrees,” he says “Sugar readings of 20 or more will make better quality raisins and also increase raisin weight.
Until then, Brar is keeping his fingers crossed. “So far, so good,” he says.