Doing the Tango has been a significant development for both the University of California, Riverside (UCR) and the global citrus industry. First introduced to growers in 2006, the Tango mandarin, developed at UCR, has become a major innovation in citrus cultivation and marketing.
According to data from the University of California system, the Tango mandarin has generated over $70 million in economic value for UCR since its release. This makes it one of the most successful innovations in UC history. The fruit is sold under various brand names such as Cuties, Halos, and Tango Fruit. Its appeal lies in being virtually seedless, easy to peel, and suitable as a healthy snack for consumers while providing a reliable crop for growers.
After nearly twenty years of exclusivity in the United States, the plant patent for Tango has expired domestically. This change allows U.S. growers to plant this variety without paying royalties. However, international protections remain in place so royalties will continue from overseas growers.
The impact of Tango on agriculture is substantial. In 2024, it accounted for almost 20,000 acres or 32 percent of all mandarin acreage in California—the largest share among mandarin varieties—according to the California Department of Food and Agriculture. With total mandarin production valued at $855 million during the 2024–25 season by the U.S. Department of Agriculture, Tango contributed about $272 million.
Tango mandarins are now cultivated in more than 20 countries and sold in over 50 countries worldwide. Recently, a European trade association named it “Flavor of the Year” in Spain and Portugal.
Brian Suh, UCR’s senior executive director of technology partnerships said: “Taking into account the entire supply chain, from nurseries and farms to packers, transporters, and retailers, Tango has revolutionized the citrus industry in its 20 years of existence, generating a significant economic impact each year.”
The development began with Professor Mikeal Roose and Timothy Williams at UCR’s Department of Botany and Plant Sciences during the 1990s. Supported by the California Citrus Research Board, they aimed to create a consistently seedless mandarin using gamma irradiation on buds—a process that accelerates natural mutations that might otherwise take many years.
Roose explained: “Some genetic changes happen, some don’t,” adding that patience was required as trees matured before promising candidates could be identified.
Eventually seven trees showed potential but only two stood out; ultimately one was selected due to having fewer seeds—this became known as Tango.
The variety offered advantages including highly sterile ovules preventing seed formation even when planted near other varieties; its pollen is also sterile so it does not contribute to seeding nearby crops. These features reduced costs associated with bee management and eliminated conflicts between growers and beekeepers.
Roose noted: “It’s very easy to grow in the nursery… It works well on main rootstocks we use… grows vigorously… produces heavy yields.” He added that careful management prevents overbearing—a common issue with mandarins—but otherwise described it as an ideal variety for growers.
For consumers, benefits include ease of peeling, suitability for lunchboxes due to size and firmness, long shelf life aiding shipping logistics globally—and late-season ripening which extends market availability.
“It had all qualities you want in a mandarin—easy to peel… great flavor… very low seeded even when grown near other varieties,” Roose said.
Williams reflected on their work: “You spend years working with hundreds of trees… then one day there it is—the one that checks all boxes… When you see it in grocery stores… around world—that’s a pretty good feeling.”
Tango joins other notable contributions from UCR such as Oroblanco grapefruit among more than forty new citrus varieties developed since opening its Citrus Experiment Station in 1907. The university also maintains one of world’s largest collections preserving citrus biodiversity through its Givaudan Citrus Variety Collection with about 4,500 trees representing over 1,000 types.
Williams concluded: “When you look at Tango’s success… it also reminds you we’re just one chapter in much longer story… The challenges facing citrus today—new diseases climate sustainability—are different from those a century ago but mission is same: keep California citrus viable valuable accessible well into future.”
