LSU AgCenter sweet potato breeder Don Labonte, left, describes new sweet potato varieties during a field day Aug. 16 at the LSU AgCenter Sweet Potato Research Station in Chase, La. (Photo by Linda Benedict. Click on photo for downloadable image.)

LSU AgCenter researcher Arthur Villordon, right, displays two sweet potato transplants and explains how different watering treatments caused the roots to differ during a field day Aug. 16 at the LSU AgCenter Sweet Potato Research Station in Chase, La. (Photo by Linda Benedict. Click on photo for downloadable image.)

LSU AgCenter weed scientist Donnie Miller tells how producers should “mix and match” herbicide treatments to control weeds in sweet potatoes during a field day Aug. 16 at the LSU AgCenter Sweet Potato Research Station in Chase, La. (Photo by Linda Benedict. Click on photo for downloadable image.)

News Release Distributed 08/17/12

CHASE, La. – Two new sweet potato varieties – Orleans and 07-146 – were featured at the LSU AgCenter Sweet Potato Research Station field day Aug. 16.

This is the first time two varieties have been released in the same year, said LSU AgCenter sweet potato breeder Don Labonte.

“We think it has a lot of prospects for the industry,” Labonte said of Orleans, which was started in the breeding program in 2005. It compares well with Beauregard, which has been the industry standard since it was released by the LSU AgCenter.

Orleans has good production capabilities, he said. In three of four plots, it outyielded Beauregard in U.S. No. 1 grade sweet potatoes.

The other new variety, 07-146, is different, with red skin and good sugar content, Labonte said. “It’s a very good french fry sweet potato.”

It produces significant yields of U.S. No. 1 potatoes with “double-digit gains over Beauregard” in the range of 15 percent to 20 percent. “When we dig our plots, we see we have something special,” Labonte said. “It’s really a good sweet potato.”

The variety 07-146 is licensed to ConAgra, and out-of-state growers must have a license with the company to grow the variety. Louisiana growers who want to plant it for the fresh market must purchase a license through the LSU AgCenter.

Labonte, who heads the AgCenter’s sweet potato breeding program, reviewed the breeding and selection process during a number of stops on the field tour. “We have to select for superior flavor, and that’s what we do every day,” he said.

Now in the 76th year of sweet potato breeding – the oldest program in the world – the research station has two new lines that are “coming along fast,” Labonte said.

Labonte said his work has increased focus on looking at how varieties perform in other parts of the country. “We know our home base in Louisiana, but if we can get out-of-state producers helping to contribute to our research programs, we can improve,” he said.

In addition to variety development, research at the station covers all aspects of sweet potato production, handling and pest management.

Arthur Villordon, a researcher at the station, is conducting research to find consistent and predictable results in crop yield and management. His current plot work compares nitrogen fertilization, irrigation, row heights and plant spacing.

“We’re providing incremental steps that translate into expected yield per acre,” Villordon said.

The Specialty Crop Research Initiative, a grant-funded program of the U.S. Department of Agriculture’s National Institute of Food and Agriculture, includes producers in evaluating new production practices.

“We’ve changed the way we do things,” said Larry Fontenot of E&L Produce in Evangeline Parish. “This work has helped us tremendously, but we still have more to learn.”

Ted McDermott, sweet potato manager for R.D. Offutt Co., said he is interested in irrigation and in monitoring the results of Villordon’s research.

Because of restrictions, growers have gaps in herbicides available for use after sweet potato planting, said LSU AgCenter weed scientist Donnie Miller.

Nutsedge, alligator weed and smell melon are problem weeds, Miller said. Producers have to “mix and match herbicides for best control.”

Sweet potatoes are planted following herbicide treatments, and the process of planting disturbs the herbicides in the soil. “You always have to go to full label rates,” he said.

Miller is looking for alternative herbicides to fill in the gaps. “A lot of times small plot research doesn’t translate to larger areas,” he said.

Theresa Arnold, a graduate student and research associate at the station, is researching relationships among plant spacing, fertility regimes, planting date and harvest date. She’s “looking at every possible combination you can imagine” to learn how best to maximize production of new varieties such as Orleans and 07-146.

Microscopic worms in the soil called nematodes also cause problems for sweet potatoes. Reniform nematodes have become more of a problem than root knot nematodes, said Tara Smith, LSU AgCenter sweet potato specialist and resident coordinator at the Sweet Potato Research Station.

Smith has been evaluating rates and application regimes of chemicals to combat nematodes. “It’s critical to sample in fall,” she said of the worms that effect yield and cause quality problems.

The sugarcane beetle is no longer considered a “sporadic” insect, Smith added. “It is a huge problem for us.”

Smith and Julien Beuzelin, an LSU AgCenter entomologist, are evaluating several insecticides that may be effective on sugarcane beetles. They have a three-year, $74,500 Louisiana Department of Agriculture and Forestry Specialty Crop Grant for research on sugarcane beetles in sweet potatoes.

Beuzelin has two plots in St. Landry Parish for evaluating soil insects.

LSU AgCenter scientist David Picha, who specializes in post-harvest care of horticultural crops, talked about post-harvest care of sweet potatoes and how it affects flavor and quality.

Picha is looking at how temperature, humidity and variety affect sweet potato marketability. “Profiles differ for different end products,” he said. New varieties store well under the right conditions, and the Orleans variety is slightly sweeter and keeps as well as Beauregard.

The United States is a leading exporter of sweet potatoes to Europe, Picha said.

AgCenter plant pathologist Chris Clark is studying how to reduce virus infections in sweet potatoes in the field.

The sweet potato verification program is collecting cost and price information, said AgCenter economist Kurt Guidry. He said sweet potatoes have had a substantial increase in acreage since 2005, but weather prevented all the sweet potatoes planted from being harvested.

The projected crop for 2012 is 25 percent higher in the five-year average for the second consecutive year. Guidry said he sees a “tremendous growth in demand and exports.”

Demand may be slowing down a bit, however, and supply may outpace demand, he said.

Acreage planted in North Carolina has increased but it is down in Louisiana, primarily because of weather, Guidry said. In addition, the cost of producing an acre of sweet potatoes is from $3,000 to $3,500 compared with significantly lower costs for producing corn and soybeans, which are bringing high prices.

“Profit margins have shrunk for sweet potatoes,” Guidry said.

More than 175 people attended the field day, including producers and industry representatives from several states, including Louisiana Arkansas, Alabama, Mississippi, North Carolina, Oklahoma, Texas and Washington and from Canada.