Fresno County Thompson seedless vines have begun to push buds.
“The leaves were still tightly enclosed inside the buds at that point,” says Steve Spate, grower representative for the Raisin Bargaining Association. “Rain has been noticeably absent this winter. There isn’t a lot snow in the mountains, either.”
Some growers have turned on their drip systems and are running water in furrows to check for any repairs that might be needed before the new season gets fully underway. That was the first time they had put on any water since their fall irrigation.
Powdery mildew control programs begin not long after the first signs of green.
“You can’t wait to treat for powdery mildew until you see it,” Spate says. “You have to be ahead of the curve and make preventive applications of fungicides. Many growers start spraying either when there is 6 inches of new growth on the vines, or at bud push, to knock out any powdery mildew spores that may overwinter in the field.”
Despite an increase in grape prices over the past two seasons, few, if any, acres have been planted, he says. In fact, raisin grapes are being pulled out faster pace than new ones are being planted. He knows of only one grower putting in new Thompson seedless vines this year. In that case, the producer is replanting east-west rows to replace north-south rows for better drying of the raisins.
“Any grower putting in new raisin vines would probably go with Selma Pete or Fiesta, which mature about two weeks earlier than Thompson Seedless,” Spate says. “This would reduce weather risks and give them the option of replacing more costly hand labor at harvest with some form of mechanized harvesting, such as a dried-on-the-vine system.