Grower Experience with Dried-on-the-Vine Raisin Varieties

Dried-on-the-vine raisin varieties offer significant potential for the industry. The varieties can eliminate some of the labor required in raisin production. Ranch manager for Marthedal Enterprises, Austin Hubbell said they are looking towards the future with some of their trial blocks. Although the dried-on-the-vine varieties come with their own challenges, they still present an interesting opportunity for growers.

“As soon as the Sunpreme variety went public we placed an order for vines, and we knew we had to give it a shot to either prove or disprove it. Today we have about nine acres in total of Sunpreme, five of which is a rootstock test plot,” Hubbell explained. “Thus far, with the Sunpreme variety, I think we’ve seen good results in terms of production, in terms of moistures, and overall grape qualities.”

One of the challenges of dried-on-the-vine raisins is premature fruit shatter. There is also potential for problematic timing. Raisins may not be fully dry ahead of fall rains, which would require additional processing steps. “But nevertheless, even as we work through some of these issues, our yields on Sunpreme I feel have been commercially viable and, in my opinion, quite good,” said Hubbell.

Each grower will have their own level of acceptable tradeoffs for dried-on-the-vine varieties of raisins. A certain amount of fruit loss may be acceptable if there is enough of a decrease in the amount of labor required. Hubbell said that working to understand those specifics is a part of preparing for the evolution of the industry. That is why they seek out new varieties to test and evaluate.

“We also back in 2020 partnered with International Fruit Genetics in order to farm and manage a test plot for them of the so-called Rais-one variety that they had recently patented. We’ve had those vines in the ground now for three years, they’ve just gotten their first crop,” Hubbell noted. “If the research and trials prove successful, Sunpreme and Rais-one may become common crops on raisin operations around California.”