Farmers turn to lab-grown slips as virus cripples sweet potato production

A complex of viruses is attacking the sweet potato crop, slashing yields and driving prices to unprecedented highs this holiday season. The Ministry of Agriculture said it is working on a solution, but it may take time to implement.

Ron Hope, farm manager of Valley Island Farms in The Valley, St George, told Barbados TODAY that an island-wide shortage of sweet potatoes had emerged as farmers battled production challenges.

The supply disruption has led to higher market prices, with a pound of sweet potato now costing as much as $7—a five-dollar increase. The viruses have also severely affected two St Philip farms, Edgecumbe Plantation and Armag Farms, the island’s main producers.

Hope revealed that the impact of the viruses was so severe that a 10-acre field, which should typically yield 50 000 pounds of sweet potatoes, now produces only 5 000 pounds. He noted that the older C104 variety was hardest hit, although newer varieties such as “look-a-like” and “carrot” (CB32/CB48) were also significantly affected.

He said: “I switched from the C104 to the look-a-like and carrot varieties. The C104 is an older variety, and from discussions with experienced farmers and ministry representatives, the virus has had more years to multiply in that variety, reducing its yields. While the newer varieties perform slightly better, they are still impacted, producing scraggy-looking tubers instead of sizeable ones.”

The viruses have also increased production costs, forcing farmers to use more fertiliser to maintain yields.

“You need very fertile soil high in potassium and phosphorus, or you get no production. Even with the newer varieties, without fertilisation, you won’t see results,” he said. “In the past, a rod (10 feet) would yield 25 pounds. Now, many farmers get less than 10 pounds—sometimes even five or none.”

Hope added that sweet potatoes, which traditionally take 14 to 16 weeks to mature, now require longer periods due to the viruses, with the C104 variety taking up to 24 weeks. Adverse weather has exacerbated the problem.

“Sweet potatoes have been in short supply all year, and the situation has worsened,” he said. “My demand has quadrupled compared to last year because people cannot find sweet potatoes. Every day, more people are coming to me.”

Despite the challenges, Hope said he is striving to keep prices reasonable: “I usually harvest mechanically, but due to the extreme wet conditions, I couldn’t. I’ve had to pay workers to dig manually, and in some cases, they’ve had to pull potatoes with their hands because the soil is so waterlogged. That, combined with fertiliser costs and security measures to combat praedial larceny, has pushed my wholesale price to $4 per pound and retail to $5.”

The C104 variety remains the consumer favourite, but Hope suggested a national campaign to encourage acceptance of other varieties.

“Fertiliser is key to improving yields, but it’s not a complete solution. I don’t want to advocate for importing sweet potatoes. We can improve our yields with the right support, including clean planting material in sufficient volumes.”

Acting Chief Agricultural Officer Michael James said the Ministry of Agriculture was assisting farmers by using tissue culture to produce virus-free planting material.

“Right now, the sweet potato slips are full of viruses, which is why yields are declining. Clean planting material will reduce the disease burden,” James said. “Through the tissue culture lab, we’re working to produce and distribute clean planting material, but it will take time to scale up to meet demand.”

James suggested that farmers could multiply the clean planting material on their farms and that commercial growers might consider producing slips for wider distribution. 

sheriabrathwaite@barbadostoday.bb