The approval followed a routine review of the CL161 rice variety, and it clears the way for global marketing of this variety and other rice lines derived from it by the LSU AgCenter rice-breeding program.
The Clearfield rice lines were developed from herbicide-resistant rice discovered by Tim Croughan at the LSU AgCenter's Rice Research Station at Crowley. They are revolutionary because of their tolerance of imidazolinone herbicides, which makes it possible to control the nuisance weed known as red rice without harming the rice crop.
BASF Corp. markets both Clearfield rice and the imidazolinone herbicides, which are marketed under the name Newpath for rice.
Although CL161, one of the Clearfield lines, was developed through traditional plant breeding methods and is not genetically engineered, it was considered novel and was subjected to Canada's feed and food approval process.
"The approval, following a routine review of the CL161 rice variety, clears the way for the global marketing of this trait and any rice lines derived from it," said Matthew C. Plitt, BASF's rice market manager.
Plitt said the Clearfield Production System for rice is a unique cropping system comprised of herbicide-tolerant rice, Newpath herbicide and a stewardship agreement with growers to ensure the system's sustainability.
CL161 is the second generation of Clearfield rice lines that were developed at the Rice Research Station, according to Steve Linscombe, LSU AgCenter rice breeder and regional director. It is closely related to the variety Cypress, which was developed by the LSU AgCenter and released in 1992.
Linscombe said CL161 has a higher level of tolerance to the Newpath herbicide than the earlier-generation varieties that have been marketed as CL121 and CL141 since 2001. All three varieties will be available to growers in 2003.
"The higher level of tolerance will allow considerably more flexibility in both agronomic practices and herbicide timing," Linscombe said of CL161. "This should lead to a greater success in controlling red rice."
Red rice, because it belongs to the same species as cultivated strains of rice, historically has been difficult to control.
Linscombe said the higher tolerance for the herbicide will allow producers to plant CL161 in clear water and apply the herbicide in two, post-planting applications. The earlier varieties require planting in dry soil with one herbicide application made prior to planting.
"Water seeding will allow more planting flexibility and more red rice control through cultural practices," Linscombe said.
BASF also received full U.S. federal label registration on rice production with Clearfield technology. The label allows for two post applications as well as clear water planting on all varieties or hybrids with the enhanced-resistance gene. This includes CL1612 and Clearfield XL8, a hybrid available from RiceTec.
BASF reported CL161 and Clearfield XL8 will be available for the 2003 growing season. CL161, CL141 and CL121 will be available through Horizon Ag and its Orygen seed retailers, and Clearfield XL8 will be available from RiceTec.