Louisiana rice producers have experienced record yields the past couple of years, but weather has made this year's crop “fair-to-good.”
During the Northeast Louisiana Rice and Soybean Field Day held July 24 at Woodsland Plantation near Monroe, La., Johnny Saichuk, a rice specialist with the LSU AgCenter, said this summer's temperatures and rain may end up being detrimental for 2002 rice crop.
“We're starting to see signs of rice blast show up after some of the recent rains,” Saichuk said. “This is a disease that attacks the leaves and the stalk of the plant. There's not much of a problem if it attacks just the leaves, but if it moves to the stalk, it can really affect yields.”
The symptoms of blast include leaf lesions that are spindle-shaped and elongated, with brown borders and grayish centers. The disease is spread by airborne spores.
To control the disease at leaf stages, the LSU AgCenter recommends maintaining proper flood levels in the fields. In addition, producers should plant varieties that are resistant to prevalent races of the fungus and avoid excessive rates of nitrogen, Saichuk said. The use of fungicides also will help in the management of blast, he said.
Sheath blight is another disease Saichuk warned producers about. Symptoms of this disease include large spots with cream-colored centers and broad, dark reddish-brown borders that appear on the sheath, usually beginning near the water line. Alternating wavelike tan and brown bands can extend up the sheath and may include the flag leaf. The wavelike band pattern may extend out on part or all of the leaf surface.
Thick stands and excessive nitrogen applications tend to contribute to disease development, he said. But producers can use fungicides to kill the disease, the LSU AgCenter specialist added.
In addition to controlling diseases, producers should also keep insect management in mind. Boris Castro of the LSU AgCenter's entomology department in Baton Rouge, said the best times to scout for insects in rice crops are early morning and late evening.
“This is because more of the insects are out during these times,” Castro said. “These are also good times to spray because more of the insects are out and you're more likely to get a ‘quick kill’ where you wouldn't if you spray at other times.”
Steve Linscombe, regional director for the LSU AgCenter's Southwest Region and a former rice breeder, gave an update on the status of the Clearfield rice lines.
These lines were developed from herbicide-resistant rice discovered by Tim Croughan at the LSU AgCenter's Rice Research Station in Crowley, La. They are revolutionary because of their tolerance to imidazolinone herbicides, which makes it possible to control the nuisance weed “red rice” without harming the rice crop.
“The CL161 is currently in the approval process,” Linscombe said. “We hope it will be available by 2003. We believe this is the Clearfield line to the future.”
Linscombe said the CL161 has a higher level of resistance to the Newpath herbicide that is used in Clearfield systems. The existing Clearfield lines can suffer from some degree of injury due to the herbicide, he said.
Another line that is being looked at for potential release is LA2174, according to Linscombe, who said this semi-dwarf line has a good yield potential and a good grain quality, as well as good milling characteristics.
A. Denise Coolman writes for the LSU AgCenter.