Veraison in Mike O’Brien’s raisin vineyards near Selma, Calif., started about 10 days later than usual this year — the berries of his Selma Pete vines began looking a little translucent on the last day or two of June. About five days later he starting seeing the same sign that the berries were taking on sugar in his blocks of Thompson seedless.
Mike has been farming for 25 years. He and his father, Larry, who owns a separate operation, join forces for work on each other’s vineyards. Between them, they grow 180 acres of raisin grapes.
By mid-July they continued to hold the advantage in their long-running battle against powdery mildew this season, while facing lower-than-normal insect threats to their crop. The vineyards were healthy and in fine shape, Mike says.
“The vines look better now than I’ve ever seen in July. The weather the last few weeks has been really good for our crop.
That wasn’t the case early this spring, when, in no more than 15 minutes late one afternoon, they were clobbered with 2-1/2 inch hailstones.
“We had several waves, when the hail would get heavy and then lighten up before starting in again. When the storm was over, it looked like everything was covered with snow. A neighbor, a mile away, was hardly touched, but growers west and north of us had a lot more damage than we did, with bunches stripped off their vines.”
The O’Briens lost a few bunches, but most remained on the vine.
“The vines looked like someone had gone through with a shotgun and shredded the leaves,” Mike says. “The bunches were out about an inch at the time and curled up afterwards.”
Initially, he thought the hail had just thinned the bunches. But, somewhere along the line, the lower extension of the bunches had snapped off and dried up. As the bunches developed and grew out about 6 or 8 inches, they appeared to be only a half rather than a full bunch. Mike isn’t sure if that reflects the impact of the hailstorms or what he suspects was freezing temperatures the following morning.
“We’ve had hailstorms before, but I’ve never seen this much hail or this type of bunch damage before,” he says.
At first, he thought damage from the hail was relatively light. Now, he’s not sure. By the second week of July he wasn’t seeing the number of grapes on his vines that he’d like. He’s hoping the vines responded to fewer grapes by producing more sugar so he can still harvest acceptable tonnage.
It took a long time for his vines to recover from the hail. Cane growth was slow and somewhat limited in various spots in the vineyards, but by the first half of July much of the canopy had filled in.
“There are still some areas that didn’t develop a full canopy, and I’m still concerned about next season because the fruiting canes for next year were damaged by the hail.”
Mites haven’t been a problem for the O’Briens this year, except for one ranch where he had to treat. They’ve also put on spotty insecticide spray for mealybugs. That treatment also controls leafhoppers, which haven’t posed a threat in their vineyards for some time, Mike notes. Neither have worms. In fact, he didn’t apply any worm sprays this year.
However, pressure from powdery mildew has been unusually high. Starting with several applications of micronized sulfur early in the season, before switching to the dry form, the O’Briens have been dusting their vines with sulfur every 7 to 10 days, depending on the weather.
Also, unlike last year when they made one fungicide application to treat for powdery mildew, they’ve sprayed a different sterol inhibitor product four times since bloom in late May.
As things look now, they are likely to begin harvesting their Selma Pete grapes around Aug. 10, followed by Thompson seedless a week or two later. They pick the grapes by hand, laying them on individual trays to dry.
“I don’t know if berry size will be what I want to see, because of the hail damage and the continued cool weather for quite some time after that, which really delayed growth,” Mike says. “But, all in all, if the weather holds and sugar comes in at a respectable level, we should be able to make a good quality raisin crop this year.”
It happened in 2010. “Last year our crop was behind in development and just prior to harvest everything came together,” he says. “The sugar came up and we made a much better quality product that we thought we could. You just never know.”
Mike isn’t tempted by highest-ever opening winery offers for green Thompson seedless grapes for crushing — $250-per ton — to make his grapes into juice instead of raisins this year. After all, he’s the fourth generation of his family to make raisins. In fact, the last time the O’Briens sold green grapes was in the early 1970s.
“Raisins have treated us well, and we’ll continue to make them,” says Mike, who hopes to make the final payment on his ranch this year, an achievement not without challenges.
“The past decade has been pretty tough and, because of low raisin prices, a lot of acres of Thompson seedless have been taken out of production,” he says. “I don’t know if the next decade will be great for raisin growers, but I think it will be a lot better than the last 10 years. I hope there are enough green grapes as well as raisin grapes for everyone this year.
“Right now we’re in a nice, balanced supply/demand situation, where raisin packers are making money and raisin growers are making money.”