LSU AgCenter entomologist Gene Reagan discusses insect management research at the 29th Annual Sugarcane Field Day at St. Gabriel on July 20. New sugarcane varieties, soil fertility and weed control were also featured. (Photo by Johnny Morgan. Click on photo for downloadable image.)

ST. GABRIEL, La – Scientists discussed the strengths of new sugarcane varieties and various management options available to growers during the July 20 sugarcane field day at the LSU AgCenter Sugarcane Research Station.

In May, the LSU AgCenter, working with the U.S. Department of Agriculture and the American Sugar Cane League, released HoCP 04-838, a new sugarcane variety, LSU AgCenter sugarcane specialist Kenneth Gravois said.

“This variety has good yields, a good disease and insect resistance package, and we believe it has the best cold tolerance that we’ve ever had,” Gravois said. It’s important to have a cold-tolerant variety because growers are continuously trying to beat the first freeze of the year.

Approximately 420,000 acres of sugarcane are planted in Louisiana this year, with about 45 percent of that total planted in the variety HoCP 96-540 with L 99-226 coming in second.

Growers are encouraged to diversify their crop to get the most from disease and pest resistance, Gravois said.

The dry spring caused some stress for many Louisiana crops, but it hasn’t had a negative effect on sugarcane. Gravois said the colder-than-normal winter helped to keep disease problems down, which has allowed for a good crop so far.

The price that growers are receiving for their crop is fairly decent right now, Gravois said.

“The growers have been able to replace some much-depreciated equipment and also to put some money back into their operations that have been running lean and mean for a number of years,” Gravois said.

The goal of the AgCenter’s sugarcane breeding program is to look for ways to increase the sucrose levels in the plants and also to increase disease resistance, said LSU AgCenter plant breeder Collins Kimbeng.

The process of developing a new variety normally takes about 12 years from first cross to release of the variety.

“During this time we are able to look at the variety growing in different locations around the state, and by year 12 we are sure that it will do what we say it will do,” Kimbeng said.

Before the release of HoCP 04-838, there had not been much concern for cold-tolerance, Kimbeng said.

“But with the program leaning more toward bioenergy cane, we are more interested in growing cane further north where temperatures get lower,” he said.

Each year there is some concern for cold tolerance, Kimbeng said, but it has not been a major issue in past years.

Other issues discussed during the field tour included soil fertility, insect and disease management and weed control.

The focus of the soil fertility project in sugarcane is to look at nutrients that are needed in the largest amounts, according to LSU AgCenter soil scientist Brenda Tubana.

“These are nitrogen, phosphorus and potassium, but we also are focusing on micronutrients, which are essential to the crop but in smaller amounts,” Tubana said.

Research on insecticides to control the Mexican rice borer is showing promise, LSU AgCenter entomologist Gene Reagan said.

“We’ve found that we need to have the chemical on the plant before the insect hatches and bores into the plant and is protected from the spray,” Reagan said.

Using disease-resistant varieties would be the way to control disease in a perfect world because it would decrease cost to the grower, but that’s not possible, LSU AgCenter plant pathologist Jeff Hoy said.

“The problem is, if we breed for disease resistance totally, we could affect yield. And we know that the No. 1 priority of the breeding program is yield. Also the No. 2 and No. 3 priorities of the program are yield,” Hoy said.

Dry weather has been good for the management of Bermuda grass unlike last year when there was lots of rain during the growing season, LSU AgCenter weed scientist Jim Griffin said.

“You may recall I told you last year that the best way to control Bermuda grass is when it’s very dry,” Griffin said. “Last year, almost every time we worked the fields, we would get a rain, and the Bermuda grass would reroot and come right back. This year has been different.”

One problem that growers face is calculating the cost of leaving ground fallow, Griffin said. He now has a computer program that allows the grower to put in the individual costs, and the program will calculate the total cost of leaving the land fallow.

The Excel spreadsheet is free and available on the sugarcane weed management webpage of the LSU AgCenter website www.LSUAgCenter.com.

Johnny Morgan