New sugarcane varieties are increasing yields, but diseases pose a constant threat, farmers were told by LSU AgCenter researchers at a recent sugarcane field day at St. Martinville, La.

The mid-July event was held for farmers in St. Martin, Lafayette and St. Landry parishes.

Researchers told farmers that developing new varieties is an ongoing effort. “Trying to stay one step ahead of rust is getting to be quite an ordeal,” said Ken Gravois, LSU AgCenter sugarcane breeder.

The excellent stubbling ability of the variety LCP 85-384 has not been duplicated in many of the newer lines and varieties, Gravois said. A new variety, L 01-283, with good stubbling ability is being released during 2008.

Jeff Hoy, LSU AgCenter pathologist, said serious brown rust problems could develop with the variety HoCP96-540, currently grown in more than half the state's acreage. He said rust outbreaks became significant when acreage of LCP 85-384 reached that level.

Hoy said fungicides may be helpful against brown rust, and a Section 18 Emergency Use label was granted for the fungicide Headline for use during the spring.

“I think over time we are going to have a continuing, cyclical problem with rust, and fungicides will help reduce losses during those times,” he said.

Orange rust, another rust disease affecting sugarcane, was found in Florida cane fields during 2007, Hoy said. Louisiana growers could be finding it soon. “We are anticipating it is going to show up this year or the next,” Hoy said.

Hoy said preliminary variety resistance evaluations are being conducted for orange rust in Florida.

Gene Reagan, LSU AgCenter entomologist, said the Mexican rice borer has been found in Chambers County, Texas, near the Louisiana-Texas state line.

Meanwhile, the sugarcane borer continues to be a pest of Louisiana cane growers, Reagan said, and research is showing that early planting could make sugarcane more susceptible to the insect.

Jim Simon, general manager of the American Sugar Cane League, said the recently announced decision by the U.S. Sugar Corp. in Florida to discontinue growing sugarcane in Florida theoretically could have implications on Louisiana's cane industry. The corporation produces 8 to 9 percent of the nation's sugar.

Simon said U.S. Sugar's cane acreage allocation could be divided up among other states, including Louisiana.

“To date, we (Louisiana growers) haven't used all the allocation we have,” Simon said.

If sugar prices remain at current levels, he said, Louisiana farmers may increase their acreage when U.S. Sugar sells its fields in five to six years.

Simon said Louisiana farmers are benefiting from the choice made by many sugar beet growers to grow more profitable crops such as corn and soybeans. Beet acreage has fallen 15 percent, he said. In addition, growers in Mexico are not having a good year and overseas sugar producers are not willing to pay expensive fuel costs to ship foreign sugar to the United States, he said.