US (MN): Sweet potato undercutter studies show promise
The undercutter digs below the surface with a V-shaped blade to cut the roots that feed the potato from the soil. This stops the flow of nutrients and water to the potato and induces a state of shock that causes the skin to toughen, Ward said. “Our preliminary studies show some increased skin strength in some varieties,” Ward said. “But we still have some questions to answer about whether undercutting improves storage performance and translates into value for the grower.”
The MSU prototype can undercut two 40-inch rows and can be adjusted to standard row spacing. It is constructed with a homemade toolbar and attachments from Roll-A-Cone Manufacturing. “This is not the only undercutter out there,” Ward said. “This approach is used in other crops, but we built this one with existing parts that can be purchased now,” Ward said. “After we establish that it works and how best to use it, a grower can quickly adopt this system and likely start with parts they already have on hand.”
Whether growers sell their potatoes in the fresh market immediately after harvest or in a year-round market, storage losses are a concern. “A sweet potato’s skin is its first line of defense against organisms that might cause spoilage,” said Stephen Meyers, regional sweet potato specialist with MSU’s Extension Service. “If the skin is damaged, the sweet potato, which is 85 percent water, is more prone to lose moisture and subsequently weight. Weight loss translates to lost revenue for sweet potato farmers and reduces the quality of the sweet potato. Sweet potatoes with excessive damage to the skin won’t sell in the fresh market because they don’t look good.”
A faster skin set would allow growers to harvest large numbers of potatoes quickly, allowing growers to keep enough potatoes on hand to sell all year. The prototype is undergoing a number of field tests at MSU’s Pontotoc Ridge-Flatwoods Experiment Station and in Vardaman and Arkansas. Ward said the machine could undergo more modifications depending on the test results.
For more information:
Dr. Jason Ward
Mississippi State University
Tel: 662-325-3282
Email: [email protected]
