By the first week of May, most of the Thompson seedless raisin vineyards in the Fresno, Calif., area were in full bloom, says Jerry Rebensdorf, president of the Fresno Cooperative Raisin Growers, Inc. This follows the earlier raisin-type grapes – Selma Pete, Zante currants and Flame seedless – which reached full bloom in the last part of April.
While about two weeks sooner than usual, this year’s bloom occurred about the same time as last year.
The acreage of raisin-type grapes grown by his cooperative’s members is unchanged from last year, Rebensdorf notes. That’s in contrast to a drop of an estimated 5 percent to 10 percent or more for their neighbors who pulled out vines this winter.
“Just about all that acreage is being replanted with almond or other tree nut orchards,” he says. “Tree nuts are a lot more profitable crop. But the main reason growers are taking out raisin vineyards is the lack of labor to harvest the raisins.”
Water also remains an issue. In mid-April and again near the end of the month, some growers in this area of the San Joaquin Valley received close to half an inch of rain over two separate events. About .15 inches of rain fell in the first week of May. “While welcomed, it wasn’t enough to put a dent in the water shortage,” Rebensdorf says.
Raisin growers are slated to receive no surface water this season to irrigate their vineyards, Rebensdorf says. Last year, they received water for two months – June and July.
Meanwhile, wells for many of the cooperative’s growers have gone dry, he reports.
“Some are getting water from their neighbors,” he says. “Some are waiting as long as nine months to drill existing wells deeper. Even then, they are waiting several more weeks to get the pumps and bowls that have to be ordered to match each well.”
Last year, water tables in this area began dropping from 70 feet below the surface to current levels of about 85 feet below ground level.
Three of the wells supplying Rebensdorf’s raisin vineyards ran dry in 2014. Since then, he’s deepened one to a depth of about 200 feet. The other two were deep enough that he could lower the bowls to where he hopes they’ll continue to provide water, at least through this season, he says.
Due to the relatively shallow depths of wells in this area of the Valley, ground water quality isn’t the concern here as it is on the West Side. There, wells may extend as deep as about 500 to 1,000 feet below the surface, Rebensdorf says.