Prime Time for Sweet Potatoes

The sweet potato digger at the LSU AgCenter Sweet Potato Research Station at Chase uses a blade that digs up the potatoes and walks the potatoes up a conveyer while shaking off the dirt to a place where six people then put the potatoes in bins. (Photo by Mary Ann Van Osdell)

"Festive Holiday Yams" in the "Serving Louisiana" cookbook available from the LSU AgCenter.

Freshly harvested sweet potatoes. (Photo by Mary Ann Van Osdell)

Louisiana also boasts the only sweet potato research station in the country. It’s a 307-acre site in Chase. The Sweet Potato Research Station was established in 1949 through a direct legislative act.

‘Louisiana Yams’
The correct answer to the question, “Is it a yam or a sweet potato?” is “yes and no,” says Tara Smith, LSU AgCenter sweet potato extension specialist.

“The terms yam and sweet potato are used interchangeably in the U.S. markets when referring to sweet potatoes,” Smith said. “But true yams and sweet potatoes are actually unrelated and two completely different plant species.

“The term yam as it relates to sweet potatoes was coined several decades ago by Louisiana growers,” Smith said. “It was used as a marketing tool to help distinguish their softer, sweeter and moister varieties from the drier varieties traditionally grown on the East Coast.”

To add further confusion, there is also a practice of referring to fresh sweet potatoes as “sweet potatoes” and cured sweet potatoes as “yams.”

“Freshly harvested sweet potatoes are referred to as green, and the sweet potatoes fresh off the turn row aren’t as sweet, soft and moist as cured sweet potatoes,” Smith said. “Sweet potatoes are sweetest when baked if they are allowed to cure six to eight weeks following harvest.”

Freshly harvested sweet potatoes are shipped to market beginning with the new crop in July and August until about the first part of November. Those shipped for the Thanksgiving market and thereafter are generally cured, meaning they have been harvested and stored long enough for them to develop the desired flavor and texture when baked.

2007 Crop
Sweet potato harvest conditions in Louisiana have been more cooperative in 2007 than in 2006, when late season rains caused several acres to go unharvested.

And though the acreage is down slightly – 15,000 acres compared to 16,000 acres – the yields should more than compensate.

Average total yields per acre are ranging around 300-350 bushels per acre, Smith said, adding, “Some producers have seen yields in certain fields of 400-600 bushels per acre.”

Movement of the early harvested portion of the 2007 crop has been strong.

“Louisiana producers are pleased with the current prices they are receiving and are confident about the quality of the potatoes going into storage,” Smith said.

Several growers have had to rent additional storage facilities for their crop, Sistrunk said.

"Consumers are beginning to understand the health benefits of incorporating sweet potatoes into their diets," Smith said. "We’re seeing a push for a quality stored product, which is why a lot of growers are putting in storage facilities that can hold sweet potatoes for up to a year.”

She said the holiday demand will be satisfied by this year’s crop.

“There are a lot of different ways to use sweet potatoes. They are not just a baked item on the table at Thanksgiving anymore," Smith said.

New Variety 'Evangeline'
A new variety, Evangeline, which was released by the LSU AgCenter in early 2007 was planted in small plots on several farms this year. In addition, several acres of Evangeline seed were planted at the Sweet Potato Station in 2007, and many Louisiana producers will have an opportunity to evaluate the variety on a limited commercial scale in 2008. 

One of the more unique projects at the station is the planting in greenhouses of approximately 30,000 true seed from the breeding nursery in Baton Rouge. Each of these seedlings is a potential new variety.

Eat Sweet Potatoes
They’re good for you. They’re low-calorie and loaded with beta-carotene. Here’s a recipe from the LSU AgCenter’s “Serving Louisiana” cookbook.

Serves 10

8 to 10 yams
2 cups fresh cranberries
1/3 cup walnuts, chopped
1 cup orange marmalade
½ cup packed brown sugar
¼ cup (1/2 stick) butter
¼ cup honey
1 tablespoon lemon juice
1 tablespoon orange juice concentrate
½ teaspoon cinnamon
¼ cup brandy

Combine the yams with enough water to cover in a saucepan. Bring to a boil. Boil just until tender; drain. Let stand until cool. Peel and cut lengthwise into halves. Arrange the halves overlapping in a 9x13-inch baking dish. Sprinkle with the cranberries and walnuts.

Combine the orange marmalade, brown sugar, butter, honey, lemon juice, orange juice concentrate and cinnamon in a saucepan. Cook until the butter melts and the mixture is of a syrupy consistency, stirring frequently. Remove from heat. Stir in the brandy. Pour over the prepared layers. Bake at 350 degrees F for 30 minutes or until bubbly.

(This AgCenter Lead was updated on Nov. 8, 2007, by Linda Benedict.)

The LSU AgCenter is one of 11 institutions of higher education in the Louisiana State University System. Headquartered in Baton Rouge, it provides educational services in every parish and conducts research that contributes to the economic development of the state. The LSU AgCenter does not grant degrees nor benefit from tuition increases. The LSU AgCenter plays an integral role in supporting agricultural industries, enhancing the environment, and improving the quality of life through its 4-H youth, family and community programs.