VARDAMAN, Miss. -- Spring rains created two sweet potato crops in Mississippi, and the later-planted crop is shaping up to be better than the first as harvests get underway.
The U.S. Department of Agriculture estimated the state’s sweet potato crop was 42% harvested as of September 22nd. Analysts put the crop at 40% fair and 57% good.
Mississippi annually grows 28,000 to 30,000 acres of sweet potatoes, mostly in Calhoun County and surrounding areas. Calhoun County alone has 9,190 acres of sweet potatoes this year, up slightly from last year’s acreage. Other acreage is scattered across the Delta and in Tate County.
Mark Shankle, a researcher with the Mississippi Agricultural and Forestry Experiment Station at the Pontotoc Ridge-Flatwoods Branch Experiment Station, said harvest of fresh-market sweet potatoes is somewhere below the state average of 300 bushels per acre for the early-planted crop. The later-planted crop has the potential for a much better yield.
“The first crop was subject to dry weather after planting, which resulted in a low root set per plant that did not size up by harvest time,” Shankle said. “The second crop has the potential to be a really good crop if we get a good rainfall event soon and insect pressure does not affect quality.”
Rather than one continuous planting season, spring transplanting of young sweet potato plants, called slips, was halted because the ground got too hot and dry. Once rains fell, growers got the second round of slips transplanted.
Weed control and crop development then became a challenge.
“Preemergence herbicides require timely rain for activation, and several acres of dryland production did not get that rain,” he said.
Sweet potato plants also need rain to mature the roots to market size. Current hot and dry weather has limited root size and formed cracks in the soil that put the crop in danger of insect injury to the roots.
Some late-planted crops have experienced a flush of Southern armyworms. These defoliators are not a problem on a crop about to be harvested, but they can limit a less mature plant’s ability to finish out the crop.
Trent Barnett, Mississippi State University Extension Service agent in Calhoun County, said growers are having to scout for army worms and make pesticide treatments.
“The army worms are going through the foliage and eating the leaves, which is a concern on the crop that still needs to grow a bit before harvest,” Barnett said. “Because of the cracks in the ground, they’re eating the leaves and moving into the root and eating the first potato in some fields.”
The state has received very little rainfall in September. Dry ground can skin the sweet potatoes as they are harvested, making them less attractive for the fresh-market consumer.
“Rain will help prevent skinning and will also finish sizing up the later planted crop,” Barnett said.
Sweet potatoes are labor-intensive to plant and harvest. Workers must plant fields by hand in a two-step process of planting sweet potato pieces, which grow into the slips that are later cut and transplanted for the actual crop. At harvest, mechanical diggers pull sweet potatoes out of the ground. Field hands ride the diggers and sort the roots by hand.
USDA ranks Mississippi No. 3 in sweet potato production behind North Carolina and California, and the state’s sweet potatoes are in demand nationally throughout the year. Sweet potato supplies are low now, and demand is high and expected to become greater at Thanksgiving and Christmas.
“Calhoun County and the Vardaman area soil makes for a very sweet, good-tasting sweet potato,” Barnett said. “That is why sweet potatoes in this area of Mississippi are so sought after throughout the country. The soil helps provide the taste as well as the quality shape of the potato.”
The current market price for a 40-pound box of sweet potatoes is $22 to $24. Shankle said he expects that price to hold steady due to high consumer demand.