Rust diseases and bermudagrass control highlighted the presentations at the thirtieth annual sugarcane field day at the LSU AgCenter Sugar Research Station July 18.
“Brown rust has become our biggest problem,” said LSU AgCenter plant pathologist Jeff Hoy.
The disease comes in spring and affects sugarcane at a time that it grows most vigorously. Hoy is evaluating new fungicides and studying when and where to best treat for the disease.
“If we can minimize the losses with a good fungicide, we can have a good crop. The final question for producers is, ‘does this stuff pay?’”
Orange rust, a similar sugarcane disease that occurs later in the growing season, has been identified in several fields this year. The disease appears to have come to Louisiana by spores carried in the wind from Florida, where it has been for several years.
So far, the disease has been found on only one variety, Ho 05-961, which only has been planted for seed this year. “You have to know what you’re looking for and look hard to find it,” Hoy said of discovering an infection in a field.
Fungicides that work on brown rust also are effective on orange rust.
Bermudagrass is a persistent problem in sugarcane, but weather conditions during the past year have eased the situation this year, said LSU AgCenter weed scientist Jim Griffin.
The sugarcane crop grew rapidly this past spring and shaded out bermudagrass, Griffin said, explaining various alternatives for suppressing bermudagrass at planting.
“We cannot control bermudagrass in sugarcane, we can only suppress it,” said Griffin. Several herbicide combinations can be effective in slowing down the growth until the sugarcane crop can out-compete it.
“You get four to six to eight weeks of effectiveness following application, then the herbicides are degraded and don’t persist,” Griffin said.
He suggested sequential herbicide applications at planting in late summer. The second application helps prevent bermudagrass from re-establishing and helps control other winder weeds.
LSU AgCenter sugarcane breeder Michael Pontif reviewed the sugarcane varieties available to Louisiana growers and pointed out the strengths of each. He was accompanied by Ed Dufrene with the USDA’s Agricultural Research Service sugarcane research unit in Houma, La.
It takes about 12 years for variety development. The next new variety may be in 2014 from USDA.
Twelve years from crossing to commercialization is typical for sugarcane, said LSU AgCenter sugarcane specialist Kenneth Gravois.
Standing in front of examples of sugarcane plants in various stages of variety development, Gravois explained how wild cane from Asia was introduced into U.S. sugarcane breeding about a century ago. At that time, sugarcane grown in Louisiana began suffering from mosaic and stalk rotting diseases, and new sources of genetic material had to be incorporated into the breeding programs.
“Basic breeding doesn’t give you a commercial variety but a variety to put into the crossing program,” Gravois said.
Today, sugarcane development includes breeding for varieties to be used as biofuels that can be grown in other climates and not compete with food crops, Gravois said. “Research is the arena for innovation and risk.”
Herman Waguespack with the American Sugar Cane League presented results of planting tests with a new planter wagon. He said planting whole stalks with the equipment was more efficient and produced equivalent yields compared with other mechanical planters and hand planting.
Jim Simon, general manager of the American Sugar Cane League, commented on congressional actions concerning the new farm bill. Different versions exist in the House and Senate.
“We don’t know what’s going to happen,” Simon said. “A lot can happen over the next couple of months.”