(02/03/22) ALEXANDRIA, La. — A team of LSU AgCenter researchers gave an update to sweet potato growers at the recent annual meeting of the Louisiana Sweet Potato Association.Topics included ongoing developments within the industry including variety development, diseases and ways to combat pests such as weeds and nematodes.

While acreage has declined, Louisiana still produces a large number of sweet potatoes for both the processing and fresh markets.The crop contributes over $85 million annually to the state’s agricultural economy.

Myrl Sistrunk, an extension specialist for sweet potatoes, said this year was good in terms of yield despite the abundant rainfall during the growing season.

“This was a good year to find out just how good the drainage was on your fields,” he said.

Sistrunk said he expects yields to finish around 500 bushels per acre on nearly 7,100 acres. West Carroll and Franklin parishes represent about two-thirds of the state’s total acreage. Sistrunk also said that the processing market receives 55% of the potatoes grown in the state.

Don LaBonte, plant breeder for the AgCenter sweet potato breeding program, is looking at several new varieties that can be used for the fresh market and for the frozen and canning processing sectors of the industry.

“One of the biggest challenges I’m facing is finding a variety that has resistance to the guava root-knot nematode,” LaBonte said. “It has not been easy at all.”

LaBonte is excited about a variety currently designated as LA19-42. He believes it could play a major role for the processing side of the industry.

Chris Clark, AgCenter plant pathologist, gave an update on the effort to reduce viruses in the state’s sweet potato crop and foundation seed program.

“We know that viruses affect both yield and uniformity,” Clark said. “These viruses are nearly always transmitted by aphids.”

Clark said the wet weather did reduce aphid populations, but it did not eliminate them. He said diseases often occur on the edges of fields, and one way to reduce that problem involves planting a different crop around the edges of sweet potatoes fields to create a buffer.

Weed scientist Donnie Miller talked about efforts being studied to control weeds in sweet potato fields.

Miller indicated that the higher costs for herbicides is an issue growers can’t ignore.

“Growers need to identify what type of weeds they have in their fields and use herbicides that specifically control for those weeds,” Miller said.

The possiblepresence of heavy metals in food sources has been anissue for several years. AgCenter horticulturalist Arthur Villordon has begun researching ways sweet potato growers can minimizethe presence of nonessential heavy metals in their crops.

“Soil tests can help identify fields that have a presence of nonessential toxic heavy metals,” he said. “Growers should avoid those areas.”

Villordon also stressed that managing essential nutrients such as phosphorus, calcium, manganese and zinc play a role in reducing or eliminating concerns with nonessential heavy metals.

A recent concern of sweet potato producersinLouisiana is the guava root-knot nematode. It has been found only twice in the state and hasn’t been found in more than two years.

Tristan Watson, AgCenter nematologist, is working on ways to control the guava root-knot nematode and other nematodes that can damage sweet potatoes.

“The problem with the guava root-knot nematode is that it can break through resistance in commercially available varieties that have resistance to other root-knot nematode species,” Watson said. “We have to be very vigilant against it.”

Watson is conducting studies to look at how effective nematicides are for controlling nematodes. Several nematicides are available for use on the crop. Velum is a more recently labeled product that has shown promise in increasing yields and suppressing nematode populations.

Tara Smith, Central Region director and entomologist with extensive knowledge regarding sweet potato insect pest management, gave an update on some of the efforts being conducted by the AgCenter regarding controlling problematic insects such as the cucumber beetle.

“With the recent loss of Lorsban, we basically have three options for preplant incorporated soil insecticides,” Smith said. “They are Belay, Admire Pro and Brigade.”

Smith did say a new experimental product had shown very good results in preliminary trials, and she is hopeful that this product will be available to growers within the next two years.

Charlie Overstreet, retired LSU AgCenter nematologist was the recipient of the Louisiana Sweet Potato Association Distinguished Service Award.

Charles Overstreet, left, received the Distinguished Service Award from Myrl Sistrunk at the Louisiana Sweet Potato Association’s recent annual meeting. Overstreet is a retired LSU AgCenter nematologist and worked closely with sweet potato growers in their efforts to reduce nematodes in their fields. Photo by Craig Gautreaux/LSU AgCenter