STUTTGART — Two new high-yield, Clearfield®rice varieties developed by the University of Arkansas System Division of Agriculture will be widely available from Horizon Ag in 2020.

Professor Xueyan Sha, Arkansas Agricultural Experiment Station rice breeder based at the division’s Rice Research and Extension Center near Stuttgart, released two new Clearfield varieties, according to a news release.

The two varieties are a long-grain rice, CLL15, and a medium-grain rice, CLM04, that will be part of the Horizon Ag lineup next year, said Tim Walker, Horizon Ag general manager.

“These Clearfield varieties will provide farmers with outstanding yield and grain quality combined with the agronomic characteristics rice farmers need to manage their crops for maximum profitability,” he said.

Sha said CLL15 is a semi-dwarf rice that averaged 186 bushels per acre in 42 state and regional trials during the 2016 to 2018 growing seasons. Milling yields were comparable to other Clearfield varieties with head rice yield of 59.8 percent and total milled rice of 69.5 percent in 22 statewide and regional trials.

CLL15 has improved blast resistance compared to other Clearfield varieties and good straw strength, making it moderate resistant to lodging, Sha said.

CLM04 is an early maturing, semi-dwarf rice with outstanding yield potential, good milling and grain quality, Sha said. In 43 state and regional trials from 2016 to 2018, it averaged 198 bushels per acre, slightly better than CL272 and Jupiter, and slightly below Titan.

Milling yield averaged 60.1 percent head rice to 68 percent total rice in 23 state and regional trials, Sha said. Its chemical composition is nearly identical to Jupiter, which is part of CLM04’s breeding lineage, making it a good choice for cereal companies.

Compared to other popular medium grain varieties, Sha said, CLM04 has good lodging and blast resistance.

Clearfield rice was developed at Louisiana State University when rice breeder Tim Croughan discovered a breeding line of rice with a naturally occurring genetic mutation that was tolerant to the imidazolinone family of herbicides, said Bob Scott, Rice Research and Extenstion Center director.

LSU licensed the genetic material to American Cyanamid, now BASF, which shared the breeding material with the UA System Division of Agriculture about 1999, Scott said. Horizon Ag is a seed technology company licensed by BASF to market Clearfield rice varieties.

“Both of these new varieties will fill current needs for Southern rice farmers today and will be valuable additions to the Horizon Ag variety lineup,” Walker said. “Since 2001, Horizon Ag has brought forward rice varieties that have enabled farmers to meet the challenges they face while producing a product that returns more to their bottom line.

“CLL15 and CLM04 will continue that 20-year legacy,” Walker said.

To learn more about Division of Agriculture rice breeding and research, visit the Arkansas Agricultural Experiment Station website: Follow us on Twitter at @ArkAgResearchand Instagram at ArkAgResearch.

For more information about CLL15 and CLM04 in seed production, visit

The University of Arkansas System Division of Agriculture offers all its Extension and Research programs to all eligible persons without discrimination.

— Fred Miller is science editor with the U of A Division of Agriculture.