With tonnage up significantly from last year, improved crop quality and good drying weather the 2013 raisin harvest was continuing smoothly for E.G. Huter and his father, Elmer, Jr., through the third week of September. They grow 360 acres of Thompson seedless grapes near Kerman, Calif.
The Huters, who harvest all but 10 acres mechanically, cut their first canes this season on Aug. 19. That’s only a day earlier than last year. But, taking full advantage of this year’s good growing conditions, the grapes matured much earlier.
“This allowed extra time for the grapes to add more sugar and weight,” E.G. says. “The sugar levels were at 20 and 21 Brix when we cut the canes. As a result we have some pretty good quality raisins this year.”
After the grapes dried on the vine for two weeks, the Huters went in with their harvester to shake off the grapes and place them just two to three berries thick on continuous trays. With the high temperatures this season only another nine or 10 days of drying were needed. Starting on Sept. 10, they began picking up the trays of dried raisins with a machine built for this purpose. The Huters have an optional auger system on their pickup machine which screens the raisins before they are dropped into wooden bins. The pickup machine also shreds the paper which is then easily disked into the ground, eliminating any need to burn them.
By Sept. 18 the Huters had picked up 100 acres of raisins. A day later they had finished putting the last of their grapes on the drying trays. If the weather holds, the Huters expect to have all their raisin in bins by the end of September.
With mechanical harvesting, what little bunch rot that was on the vine this year wasn’t a problem. ”The way the machine gently shakes the grapes, the majority of the dried-up bunch rot stays on the vine,” E.G. explains. “But, if you were to shake the vine too hard it would come off with the grapes.”
Typically, yields for the Huters’ blocks of grapes average about 2 to 3 tons of raisins per acre. This year in the trellis fields, where the vines are younger, production topped 3 tons per acre. In the older, single-wire vineyards, where the vines in one field were planted more than 100 years ago, yields ranged from 2.25 to almost 3 tons per acre.
Overall, production increased about 20 percent to 25 percent above 2012 levels, E.G. notes. “Because last year was one of our smallest crops in memory, the vines weren’t stressed,” he reports. “So, they were able to produce the bigger crop this year.”
The Huters’ spray program kept powdery mildew under control this season. As elsewhere in the area, the hot, dry summer brought unusually high numbers of spider mites to their vineyards. “We spent a lot money on miticides this year to minimize their damage,” E.G. says. “But, it was worth it.”
Normally, they can produce a crop using only surface water. This year, instead of receiving enough water in the ditches to irrigate fields four or four and a half times, as usual, they got only enough for three irrigations. They received the last delivery in early June. As a result, they turned on their pumps several times after that to finish off the crop.