Clearfield Variety Helps Farmers Intensify Battle With Red Rice

News Release Distributed April 2004

The war on red rice intensified this year as more farmers nationwide added a double-barreled weapon to their arsenal.

That combination is Clearfield rice, developed by the LSU AgCenter, and Newpath herbicide from BASF Corp.

Louisiana rice farmers will plant approximately 100,000 acres of Clearfield this year, about a fifth of the total rice expected to be planted in Louisiana, said Randy Ouzts, general manager of Horizon Ag, the company that sells Clearfield.

Even more, the Louisiana planting represents about a fourth of the national use of Clearfield, Ouzts said.

The total amount of Clearfield planted this year is twice the amount grown in the United States last year, according to Ouzts, who said he expects another big increase in 2005.

"I looks like it’s going to double again next year," he said.

Most of the acreage this year – 95 percent – was in the Clearfield 161 variety, Ouzts said, adding that enough Clearfield seed remain on hand for the small percentage of plantings that won’t result in a stand this year.

Ouzts also pointed out that Arkansas farmers are expected to plant 1.6 million acres of rice this year and that 300,000 of those will be with Clearfield.

Clearfield was developed by LSU AgCenter researchers through induced mutation and conventional hybridizing and breeding practices. Development of Clearfield and some of the other research at the AgCenter’s Rice Research Station is enhanced by support from the Louisiana Rice Research Board.

Because of its success and popularity, new lines based on Clearfield 161 are under development by LSU AgCenter rice breeder Dr. Steve Linscombe, who said one of those could be ready next year. Named Clearfield 131, it matures five days earlier than 161, Linscombe said, and it has more lodging resistance since it will be about 2-3 inches shorter.

"Additional tests in 2004 will provide more information on disease resistance as well as milling stability," Linscombe said of the newer variety.

It’s being grown on the LSU AgCenter’s Rice Research Station and 11 off-station sites, including two out of state, Linscombe said. If the results from this year’s test crop are satisfactory, Linscombe said Clearfield 131 could be released for sale in the 2005 growing season.

Clearfield 161 was an improvement over the earlier lines, 121 and 141, because it is more tolerant to Newpath, allowing more flexibility for the application timing. With the early versions, farmers had to spray before emergence and then wait until the plants reached the 4-leaf stage before spraying again, Linscombe said.

But 161 offers the advantage of allowing farmers to apply Newpath after emergence and then spray again before the 4-leaf stage, which allows for better red rice control, he said.

Fred Zaunbrecher of Crowley, who farms with his three brothers, Phillip, Paul and Bill, has grown two crops of Clearfield 161 rice. He said he is eager for the release of Clearfield 131 and hopes it will have higher yields than 161.

The Zaunbrechers planted 588 acres of Clearfield, with 433 acres in 161 and 155 acres planted with RiceTec Clearfield XL8 hybrid –three times the acreage for both varieties than they planted last year. They’re also trying 60 acres of RiceTec XP716 and XP712. The rest of their 2,000 acres in rice are in Cheniere, Cypress and Cocodrie.

Conventional rice seed costs $20 an acre, Zaunbrecher said, and Clearfield is $5 to $10 more per acre. The RiceTec hybrid seed runs $85 to $90 an acre. But he said the long-term benefit of controlling red rice and higher potential yield for the hybrid has to be factored into the equation.

"Clearfield has an excellent fit when you have a severe red rice problem," Fred Zaunbrecher said.

Zaunbrecher said he’ll also use other strategies to combat the problem. In fact, he said some of his 2,000 acres of soybeans will be planted in the Roundup Ready variety – to continue the red rice battle in the rotation with rice.

The Zaunbrechers planted the third week in March. For Clearfield, they used 60 pounds of seed per acre for drill seeding and 75-80 pounds for water-seeded fields. The drill-seeded rice was planted at a depth of three-quarters of an inch to an inch, he said.

Zaunbrecher said he may have to replant roughly 30 acres where the seed appeared to have lost their vigor after germination. He said the unseasonably cool weather added another stressful condition that affected the poor seedling response.

Zaunbrecher said he favors early applications of fertilizer, ammonium sulfate and urea, followed by two more shots of urea, with the latter application dependent on the growing crop’s condition.

One application of fertilizer should be made after the second 4-ounce per acre treatment of Newpath before the permanent flood, he said.

With the second application of Newpath, Zaunbrecher said they tank mix zinc along with Karate or Mustang Max.

After the permanent flood, he said the Clearfield rice is "treated like a normal crop."

Two more shots of fertilizer might be required, along with an additional application of Karate for stinkbugs.

Zaunbrecher said the Clearfield XL8 hybrid produced excellent yields that justified the higher cost for seed. The second crop of Clearfield XL8 brought in 26 barrels per acre, "which is the highest we’ve ever cut." Their average harvest on all fields for last year’s ratoon was 15 barrels, Zaunbrecher said.

Clearfield 161 yielded 40 barrels an acre for the first crop, he said, but he thought with the good stand and excellent weather the yield would exceed 50 barrels.

Overall, Zaunbrecher said he likes Clearfield, but he said other farmers might be reluctant to try it because of the different management practices that are used.

For example, a stale seedbed requires vigilance.

"One thing you do when you’re drilling is not let the vegetation get out of hand," he said. "You have to stay on top of your burndown program."

Allowing wild vegetation to get too tall before spraying creates a moisture-holding blanket that interferes with optimum seed-to-soil contact necessary for uniform germination, he said.


Writer: Bruce Schultz at (337) 788-8821 or

4/22/2005 11:15:23 PM
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