As reported here in April, Fresno County, Calif., raisin grape grower Greg Markarian was concerned about two things; powdery mildew, a likely possibility because of the unusually wet spring conditions; and vine mealybug, increasingly a menace in his area.
Markarian Farms has 120 acres of Thompson seedless for raisins and 10 acres of Zante currants.
“When it comes to protecting my crops” he said at the time, “I don’t take chances.”
To reduce the odds of powdery mildew, he sprayed a fungicide in April when shoots were about 6 inches long. He followed that with another spray 18 days later, and then a final treatment 18 days after that.
His efforts paid off. “I stayed on top of it pretty well and didn’t really have a problem,” Markarian says. That wasn’t the case with other area growers who weren’t so diligent in trying to control the disease.
The mealybug turned out to be an even bigger issue than he figured it would be in April. “I’m glad we were treating for it then,” Markarian says.
That treatment included one application of imidicloprid insecticide in April, giving excellent control on about 75 percent of his vines. However, in late July, mealybug numbers began to rise in other parts of his raisin vineyard. Rather than risk losing part of his crop, he sprayed trouble spots with another insecticide, which did the job.
“Now, mealybugs are pretty much under control,” he says. “I’m glad I treated early in the season. Every year they seem to get a little worse.
The cool weather kept spider mites at bay. One application of a combination miticide/insecticide in June kept numbers in check.
Markarian is optimistic about the prospects for both Thompson seedless and Zante grapes for the rest of this season.
“Early this year, the Thompson seedless grapes around here were as much as four weeks behind normal,” he says. “But, they’re catching up really fast. Treating with ethephon and making sure petiole potassium levels were up has helped speed the ripening process. They look good, but it’s not a heavy crop. “The Zantes are looking good, too.”
Markarain expects hand-picking to begin Sept. 1, three to five days later than usual.
He was looking for higher raisin prices this year — but that was before Gallo came out with a surprisingly low Thompson green price of $190 per ton, which may dramatically increase the raisin crop size and reduce prices. That green price is at least $25 less than many were expecting due to the world concentrate supply/demand picture. It may force growers to make raisins to increase their chances for more income versus hauling them to the winery.
Markarian also grows wine grapes, almonds, prunes and citrus. “Some years we lose money on some crops,” he says. “But, I don’t think that will happen this year. All of them should make money.”