⋅ BY JOHN LOVETT ⋅
University of Arkansas System Division of Agriculture
The new conventional medium-grain and long-grain rice varieties developed by the Arkansas researchers to achieve increased yield potential are proving popular with seed growers.
Taurus, the new medium-grain rice developed at the University of Arkansas System Division of Agriculture’s Rice Research and Extension Center in Stuttgart, was publicly released in January 2022. Taurus has significantly outyielded other medium-grain varieties, including Jupiter and Titan, during recent seasons in the variety testing program.
All the initial foundation seed available for Taurus this year has been spoken for by seed growers. Orders are being taken through the end of February for 2024 seed. The Division of Agriculture produces foundation seed, which it sells to certified seed producers who in turn grow seed to sell to individual rice producers.
“Taurus is a step-change in yield for medium-grain rice,” said John Carlin, director of the division’s Arkansas Rice Variety Improvement Program. “We feel like it replaces Jupiter as the go-to, Mid-South medium-grain variety.”
Demand for medium-grain rice seed in the South coincides with a decrease in California’s medium-grain production due to severe drought over the past several years. The price of California’s medium grain rice has been above $30/cwt since October 2021, and as high as $35/cwt in the last few months, according to Alvaro Durand-Morat, assistant professor of agricultural economics and agribusiness for the Arkansas Agricultural Experiment Station, the research arm of the Division of Agriculture.
Although Arkansas medium-grain rice is targeted to different export markets than California’s, there could be some spillover effect on medium-grain planting intentions, Durand-Morat noted.
Foundation seed for Ozark, the new conventional long-grain rice from the experiment station, was mostly sold out by the end of January, according to Glenn Bathke, the experiment station’s Foundation Seed Program director.
For the 2024 season, the Foundation Seed Program will produce 20 percent more Taurus and Ozark seed than that ordered this year by the end of February, Carlin said.
A cross between four other conventional varieties, Taurus has a plumper kernel than Jupiter and outshined the latest Arkansas-bred medium-grain varieties, Lynx and Titan, in the 2021 trials at six locations, according to Xueyan Sha, senior rice breeder for the experiment station. In 2022, Taurus outperformed Titan by over 20 bushels per acre in the Arkansas Rice Variety Advancement Trials (ARVAT) averaged across six locations in Arkansas.
The Foundation Seed Program produced its maximum amount of Taurus foundation seed, 630 units, by utilizing a nursery in Puerto Rico over the winter. A unit is a 50-pound bag of seed.
Taurus has both Pi-ks and Pi-z genes for rice blast resistance. Milling and grain quality for Taurus, as well as lodging tolerance, are equal to or slightly better than Jupiter, Sha said.
Taurus reaches 50 percent heading in an average of 86 days, which is about three days earlier than Jupiter or Lynx but three days later than Titan, with a plant height of 36 inches. The new medium-grain variety has an average milling yield of 64 percent head rice and 71 percent total milled rice. In comparison, Lynx, which was released in 2020, offered average milling yield of 59 percent head rice and 68 percent total milled rice.
Titan will continue to be produced by the Arkansas Foundation Seed Program, while Jupiter will be phased out in 2023, Bathke said. In early February, there were 120 units of Titan and 20 units of Jupiter remaining in foundation seed inventory.
“With the reduced acres of California medium-grain rice, there will be unmet demand that Arkansas farmers could meet,” Bathke said.
With a 10-bushel-per-acre yield advantage over its predecessor Diamond, Ozark has also attracted attention among rice farmers, Carlin said. The conventional long-grain rice was publicly released in January 2022. In the 2022 ARVAT, Ozark averaged 190 bushels per acre which was an 18 bushel advantage over Diamond.
The Arkansas Rice Foundation Seed Program produced 1,500 units of Ozark seed for customers this year. Sha planted additional breeder seed at the experiment station’s research site at the University of Puerto Rico-Mayaguez’s Lajas Experiment Station. Hurricane Fiona struck the island in September 2022, but Sha said Ozark stood up well to the hurricane’s high winds.
Ozark is agronomically like Diamond with a plant height of 43 inches. Maturity for Ozark is a day or two earlier than Diamond at 88 days to 50 percent heading, Sha said. Lodging tolerance is also like Diamond with a slight improvement in milling, especially head rice yield.
Disease resistance is also like Diamond, with susceptibility to sheath blight, leaf and neck blasts, and moderate susceptibility to narrow brown leaf spot. Ozark also shows moderate susceptibility to false smut and is moderately resistant to straighthead.
Research to develop Taurus and Ozark was funded partially by the Arkansas Rice Research & Promotion Board’s Rice Checkoff program. The new varieties were developed with a complete package of management recommendations for fertilizer, irrigation and related agricultural practices. To receive the right recommendations for your growing conditions, contact your county extension agent.
The Arkansas State Plant Board offers the approval process to become a certified seed producer.