A colorful sampling of interspecific plum selections bred by Glen Bradford of BQ Genetics.

A colorful sampling of interspecific plum selections bred by Glen Bradford of BQ Genetics.

BQ Genetics

When modern varieties of plums crossed with apricots were first commercially released in the late 1980s, the new fruit offered great promise of energizing the plum industry and exciting consumers. Though the hybrid fruit, known as interspecific plums, didn’t revolutionize the plum category, it did change the focus of private breeding programs, resulting in plum hybrids much sweeter than many conventional plum varieties.

Nearly 50 varieties of interspecific plums have been developed, extending the marketing season from summer through fall, but many are being sold as standard plums, not as “new” fruit.

What happened to the new fruit category?

Fruit breeder Floyd Zaiger of Zaiger Genetics, Modesto, California, was not the first to mix apricots and plums together. About a century earlier, plant breeder and botanist Luther Burbank developed the plumcot, a 50-50 cross of the two fruits. But it was Zaiger who took the plumcot idea further, crossing the initial plum and apricot again and again with plums or apricots to result in hybrids of varying ratios of the two types of fruit. Those with more plum background were trademarked under the Pluot name; fruit with more apricot lineage were trademarked Aprium.

Dead ends

Growers and retailers were excited about the potential of the new type of plum, but the road to fame and fortune for the hybridized plums has been dotted with potholes, detours, and even dead ends.

Growers have struggled with inconsistent yields and low productivity problems, while retailers grappled with identity and marketing challenges. As other plum and apricot crossings were developed by other breeders, the name game got murky. The industry could not call the new fruits “pluots” because that name was reserved only for Zaiger varieties. Industry groups in California decided on the “interspecific plums” as the commodity term for the fruit.

High hopes

Stone fruit growers in Washington State joined others in planting new varieties of interspecific plums, enthusiastic about the potential for giving consumers plums with great taste. David Douglas of Douglas Fruit Company in Pasco planted inter­specific plums in the early 2000s, but removed the last of them last winter because he couldn’t get consistent yields. “Now, we’re completely out of the plum deal,” he said, adding that none of the Douglas Fruit growers have interspecific plums anymore. “They do well in local farmer’s markets, but only a few are still grown in the state.” (The cover photo for this issue of Good Fruit Grower was taken at Smallwood’s Harvest, a fruit stand near Leavenworth, Washington, that sells plum/apricot hybrids.)

Lynnell Brandt of Brandt’s Fruit Trees, Wapato, Washington, too, had high hopes for the new fruit in the late 1990s.

“They didn’t explode like we’d hoped,” Brandt said. “In Washington, growers have had inconsistency in production, and then on top of that, they had to develop a marketing program around the fruit.” Brandt believes that most commercial stone fruit growers in the state have removed their acreage of interspecific plums. He noted that there’s been a general ­reduction of soft fruit acreage in Washington in recent years.

Douglas said the marketing aspect of interspecific plums also was difficult. It’s tough to compete with California’s abundance of plums and ability to offer a full lineup of interspecific plums for the season, from early to late, he said. “Ours was about a two-week deal. It’s hard to get a retailer to switch product back and forth for a few weeks. It’d be like asking a retailer to switch from Northwest cherries for local product for two weeks and then go back to Northwest cherries.”

Douglas also thought the name of the fruit was confusing. Consumers don’t really understand the term inter­specific plum that industry began using to denote the ­difference between old plum varieties and the hybrids, he said. “I think it would have been better to just call them all plums. The consumer doesn’t really care about the name, just that it eats well.”

Breeding programs shift

Washington’s Douglas admits that the interspecifics they once grew were “great-eating” fruit. They just weren’t profitable to grow. However, he believes the interspecific plums have had an impact on the industry by influencing breeding programs. Breeders have taken what they’ve learned and improved the taste of new plums and interspecific varieties.

The head of Brandt’s Fruit Trees agrees. “Pluots have contributed to an evolution of fruit breeding that’s focused on sweeter flavors and new and unique fruit,” Brandt said.

Glen Bradford, who worked with his father, Norman, to develop new stone fruit varieties at Bradford Farms in Le Grand, California, and is now owner of BQ Genetics, said that the plums and plum interspecifics being bred today have much higher soluble solids than the old varieties. “They’re way sweeter—from 18° to 26° Brix—and way better than the older varieties of plums that had sugars of 14°. Everything now is based on flavor.”

Of late, his plum interspecific breeding work is focusing on developing red-fleshed fruit.

Interspecific plums come in all skin and flesh color combinations, from red or black skin and red flesh, to green skin and red flesh, to yellow-green skin and yellow flesh, to red or black skin and yellow flesh. Skin color can also be mottled. But he’s zeroing in on the dark skin and red flesh.

Bradford said there is great interest today in the health and nutritional aspects of fruit. Preliminary testing has shown that the red-fleshed interspecifics have high levels of antioxidants—even higher than blueberries or pomegranates—but more research is needed before detailed marketing claims could be made, he noted.