Total acreage harvested by mechanical means was 45,903, just over 29 percent of the State’s total raisin-type grape acreage, according to the Pacific Region Office of USDA’s National Agricultural Statistics Service. The Overhead Trellis Management System was used on 13,404 bearing acres in 2016, accounting for 8.5 percent of the total raisin-type grape acreage. Fresno and Madera County growers have 50 and 40 percent of the Overhead Trellis acreage in the State, respectively. Kern County growers have 7 percent of the Overhead Trellis acreage. Other mechanical harvest systems include Continuous Tray at 20 percent of the raisin acreage and South Side and Open Gable with about one half of 1 percent each of the raisin-type grape acreage.
Although Fresno County has the most acreage with mechanical harvesting, at 33,399, that acreage only represents 29 percent of the Fresno County raisin-type grape acreage. Kern and Madera County growers harvest 17 and 40 percent of their raisin-type grape acreage by mechanical means, respectively.
By variety, Thompson Seedless grape acreage with mechanical harvesting is 33,373 or 24 percent of the total raisin-type grape acreage. Sixty-nine percent of the Fiesta grape acreage is harvested mechanically and 61 percent of the Selma Pete acreage is harvested mechanically.
Most California raisins are produced by sun drying after placing bunches on paper trays on terraces between vine rows. The Overhead Trellis System has led to increased production of dried-on-the-vine raisins, increased machine harvesting, and decreased hand labor use.
The Pacific Region Office of USDA’s National Agricultural Statistics Service, in cooperation with the California Department of Food and Agriculture, conducts an annual grape acreage survey. The 2016 Grape Acreage Report, published in April, summarized the latest survey results. At the request of the raisin industry, an additional question was added to the grape acreage survey form the past nine years to gather information on raisin-type acreage that is harvested mechanically. In addition to the mechanical harvest data, producers were asked to update acreage by variety and year planted. Growers were initially contacted by mail and follow up was done by telephone. This report summarizes data for mechanical harvest methods of raisin-type grapes. The totals included are only for those that voluntarily reported to this survey.