“Everything is going pretty smoothly,” says Greg Markarian, Fresno, Calif., as he describes conditions in his raisin grape vineyards. Markarian Farms grows 110 acres of Thompson seedless and 10 acres of Zante currants, which are hand-picked.
“Bud break, about March 15, was very good as a result of the wet winter,” he says. “All the buds opened within about a week. Sometimes, a dry winter produces an erratic bud break.”
As of the first week of April, shoots measured about 10 inches long.
Markarian was also pleased by this year’s bunch count, averaging about 45 per vine. That’s about normal for his vineyards and up considerably from last year’s light count in the 30s, he adds.
The wet weather through early April, however, has caused him some concerns. One is the increased threat of Phomopsis cane and leaf spot. In wet spring years, the fungal disease can be particularly severe on several varieties, including Thompson seedless. He’s treated them and his Zantes with copper twice since March 25.
“If we stay in a wet pattern, powdery mildew could also be a problem,” Markarian says. That’s why he’s added sulfur to his copper spray, which he plans to apply for another four or five times until veraison.”
Last year, for the first time, Markarian found vine mealybugs in his vineyards. “They’ve become a little bit worse in this area over the past few years and seem to be spread by equipment and people” he says. “It’s almost impossible to remove all the mealybugs on a mechanical grape harvester.”
His plans called for treating his vineyards with a systemic pesticide beginning the second week of April, while the mealybugs were still in the vine bark. It costs about $40 per acre to apply the pesticide through the drip system. If necessary, he’ll apply two foliar sprays to kill any mealybugs that survive the drip application.
“When it comes to protecting my crops, I don’t take chances,” Markarian says. “If you do, sooner or later, the whole crop could be ruined.”