LSU AgCenter research, extension boost sugarcane industry

Linda Benedict  |  7/2/2008 9:25:31 PM

Kenneth A. Gravois, plant breeder, is the Graugnard Brothers Professor and Resident Coordinator at theLSU AgCenter’s Sugar Research Station in St. Gabriel. (Photo by John Wozniak)

Photo By: John Wozniak

Kenneth A. Gravois

As Louisiana begins its third century of sugar production, research continues to play a vital role that sustains both growers and processors. Many facets of the industry continue to change. Farm and factory sizes have increased. Input costs continue to climb. Labor is becoming an ever-increasing problem. Sugarcane rust disease has increased to a point of lowering yields. Sugarcane varieties once thought invincible have shown weakness, and new varieties have arrived. Unfortunately, one thing that has not changed much is price. Sugarcane farmers and processors face a host of challenges. The LSU AgCenter mission is to conduct research and extension programs that maximize production while minimizing the inputs needed for sustainable yields.

Varieties and diseases
As one reads through the history of sugarcane production in South Louisiana, the relationship between varieties and diseases is evident. In fact, much of the early sugarcane variety work was done by plant pathologists. Destructive diseases including mosaic, ratoon stunting disease and stalk rotting disease were found in Louisiana from the beginning of sugarcane cultivation. These diseases culminated their destructive effects in the 1920s by nearly decimating a once-thriving industry.

In the decades following, sugarcane varieties changed in lock step with the strain changes of mosaic. New diseases have arrived: Brown rust in the late 1970s, smut in the early 1980s, leaf scald in the early 1990s and yellow leaf in the late 1990s. Orange rust was found in Florida in 2007 and could present problems for the Louisiana sugar industry. Disease-resistant varieties have been the main line of defense against these diseases.

Kenneth Gravois and Keith Bischoff lead the AgCenter sugarcane breeding efforts. With increasing levels of brown rust in the state’s leading variety, LCP 85-384, new disease-resistant varieties are needed. Changing varieties in a perennial crop such as sugarcane is not an easy process, especially when the acreage peaks at 91 percent as was the case with LCP 85-384 in 2004. Since 2003, the LSU AgCenter, U.S. Department of Agriculture-Agricultural Research Service and the American Sugar Cane League have released seven new varieties to replace LCP 85-384. These varieties include HoCP 96-540, L 97-128, Ho 95-988, L 99-226, L 99-233, L 01-283 and HoCP 00-950. The work is ongoing as new experimental varieties continue to be developed in the breeding program. Many in the industry have said that the influx of new sugarcane varieties has kept them in business. Sugarcane varieties are truly the lifeblood of the industry.

Jeff Hoy has research responsibilities for sugarcane diseases. More recently, his efforts have included finding a fungicide to aid in the control of brown rust in Louisiana. Disease-resistant varieties have been the mainstay of control for brown rust, but other control strategies would be useful. His work has shown yield losses up to 7 tons per acre because of brown rust. The use of fungicides has helped recoup these losses with timely applications. Hoy continues to manage the Sugarcane Disease Detection Laboratory as the Louisiana industry continues its fight against an old foe – ratoon stunting disease – and new diseases such as yellow leaf. Maximizing yields from billet-planted sugarcane is another research interest for Hoy. Many growers have switched to billet planting in an effort to circumvent labor shortages. Billet planting is also the only choice if seedcane has been lodged (fallen over), such as after hurricanes.

Old, new insect pests
The sugarcane borer has caused significant yield reductions in South Louisiana. In the early days of the industry, farmers did not have many options to combat the sugarcane borer. Beginning in the 1950s, insecticides became a popular control option. Many of the early insecticides were effective but harsh on the environment. Gene Reagan leads an AgCenter entomology research program combating the harmful effects of the sugarcane borer. Over the years, Reagan’s research efforts have led to the use of pyrethroid insecticides, a new and safer chemistry. More recently, his research efforts have led to the registration of the insecticide Confirm, the most environmentally safe insecticide in use in sugarcane. Applications of Confirm specifically target the sugarcane borer while avoiding beneficial predators. Work is continuing with the insecticide Diamond, another environmentally safe insecticide. Full registration is possible for 2008.

A new insect pest is on the horizon – the Mexican rice borer. Reagan has led a multistate research effort determining the effect of this new stalk borer on Louisiana sugarcane varieties. He also has investigated the ecology of this new insect pest to determine the best means of its control. His research and monitoring efforts have tracked the eastward movement of the Mexican rice borer. Louisiana will be much better prepared when this new insect invades the rice and sugarcane growing regions of South Louisiana.

Weed control, cultural practices, environmental issues
Perennial weeds mean perennial problems. Jim Griffin leads AgCenter research and extension programs in sugarcane weed control. Weed control costs are high for sugarcane in Louisiana. Griffin’s research constantly explores ways of reducing weed control costs while maintaining good weed control. Other research efforts include evaluating new herbicides, using alternative crops as a means of weed control and testing reduced tillage systems. Griffin’s work has shown that Louisiana sugarcane farmers could reduce tillage without adverse effects on yield.

Ben Legendre conducts research on chemical ripeners, which increase the sucrose content in sugarcane. Louisiana has moved toward earlier harvests. Research has shown that chemical ripeners can increase the recoverable sugar per ton of cane by 50 to 70 pounds. His work also includes the search for alternative ripeners, such as Palisade. An alternative nonglyphosate-based ripener would be useful in the advent of herbicide-resistant crops such as Roundup Ready sugarcane.

With escalating fertilizer costs, determining cost effective fertilizer rates is the research area for Sonny Viator and Brenda Tubana. Their efforts have led to the changing of sugarcane fertilizer recommendations that include reduced nitrogen rates. Other research efforts include the fine-tuning of soil test results to match recommended rates of fertilizers.

Producing sugar with a minimal impact on the environment is another research objective within the LSU Ag- Center. Magdi Selim, Richard Bengtson and Sonny Viator conduct research on improved water quality. To economically produce sugarcane in Louisiana, sugarcane growers must burn the leafy trash residue either before harvest or after harvest. If the leafy trash blanket is left on harvested fields, yield reductions of 3 to 5 tons per acre can occur in the subsequent crop. Results from this research have led to the development of BMPs (best management practices) for sugarcane production. It is important that the Louisiana sugar industry manage itself rather than being managed by federal and state environmental mandates.

Sonny Viator has also cooperated with USDA-ARS scientist Richard Johnson on research pertaining to precision agriculture. Applying nutrients and herbicides to areas only where they are needed can decrease production input costs, maximize yields and mitigate any harmful effects to the environment. Applying variable rates of lime to fallow sugarcane fields appears to be an excellent application of this new technology.

Economics
Sugarcane farmers and processors are in business to make money. Mike Salassi assists in these efforts by preparing an annual sugarcane budget that estimates sugarcane production costs based on inputs, equipment costs and yield potential. With urban encroachment increasing, Salassi provides information on land and crop values. Another of Salassi’s current projects is to minimize transportation costs for sugar factories through hauling schedules. Mike Salassi has also been called upon by the U.S. Department of Agriculture to determine the feasibility of using sugarcane and it processing products and byproducts for ethanol production. His work has shown that the most economical sugarcane feedstock for ethanol production is molasses. Salassi works with many in the research and extension groups to apply economic analyses to their research and outreach efforts.

Sugar processing, new technologies
The Audubon Sugar Institute continues its long-standing mission of maximizing the production of raw sugar in Louisiana’s sugar factories. Records kept by personnel at the Audubon Sugar Institute show an ever-increasing trend in Louisiana factory efficiency, even as factory size increases. As the sugar industry becomes more integrated with sugar refineries, research on producing a high level of sucrose in sugar (the pol level) with optimum color continues.

As the nation looks to the agricultural sector of the economy to meet some of its energy demands, work at the Audubon Sugar Institute focuses on ethanol conversion technologies. Funding, primarily through the Department of Energy, has focused research on converting sugarcane bagasse (a byproduct of raw sugar production) to ethanol. Although bagasse is used as a fuel for boiler operations within raw sugar factories, high fiber sugarcane varieties could become more common as the technology to convert cellulose to ethanol becomes more economical. The Audubon Sugar Institute is taking a lead role as the Louisiana sugar industry hopes to diversify through energy production.

Sugarcane has helped invigorate the South Louisiana economy for more than 200 years. Research and extension efforts of the LSU AgCenter have the goal of sustaining and diversifying an industry vital to the people and culture of south Louisiana.

Kenneth A. Gravois, Graugnard Brothers Professor and Resident Coordinator, Sugar Research Station, St. Gabriel, La.

(This article was published in the spring 2008 issue of Louisiana Agriculture.)
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