Fresno County farmer Ken Shinkawa likes what he is seeing in his and other raisin vineyards in the Caruthers area on the eve of this year’s harvest.
“The fields look quite good,” he says. “Based on degree-days, the crop is maturing about 14 days earlier than usual. For growers who’ve followed proper nutrition and irrigation practices, the quality of the crop should be good.”
His vineyards totaling 120 acres of Thompson seedless grapes dates back more than a century when his grandfather planted the first vines.
Shinkawa isn’t making any yield predictions. Tight bunches are concern in some vineyards. If the developing berries press too hard against each other in the clusters, they can crack, opening them up to disease infection, he explains. That would impact final yields.
He treated his vines during bloom with gibberellic acid to thin bunches. However, he surmises, the wide variation in the stage of bloom among the clusters, made it difficult to time the spray application to be most effective in thinning to reduce berry crowding.
Shinkawa, who harvests his grapes mechanically, plans to cut the canes Aug. 19 to begin drying the grapes on the vine. Two weeks later, he’ll lay the partially dried grapes on continuous paper trays with machines to complete drying.
Hot weather in early July heightened the importance of timely control of spider mites. “The heat really brought them on,” Shinkawa says. His area has long been known as a spider mite hot spot.
“If there’s an issue with mites, you have to jump on them right away,” he says. “You can’t let the problem fester. That’s especially important in machine –picked fields, where growers may reduce more than 40 percent of the canopy with cane cutting prior to bringing in the harvesting equipment. If the vines have already been weakened by mites, cutting the canes then weakens them even more.”
Normally, one miticide application in the spring will control spider mites all season. This year, a second spray in early July was necessary. He did that just in time.
“Because of the widespread heat throughout the San Joaquin Valley this season, many growers have had to deal with high mite pressure,” he says. “There was as a big run on miticides and some growers had to settle for the second or third choice of materials. I was very fortunate, I got the product I wanted just as the last pallets came into the dealer.”
Shinkawa relies entirely on well water to irrigate his crop. Two years ago he deepened his wells by one pipe section or 20 feet and replaced the existing pump with a larger one. Now, he’s wishing he’d have gone deeper.
“Based on past experience, that additional 20 feet should have been enough,” Shinkawa says. “But, I should have deepened the wells two sections. The additional water growers on the West Side have been pumping this year due to cutbacks in surface water deliveries is reducing the level of the water table for all growers.”
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