Sweet potato greens could offer consumers a nutritious new vegetable option while creating an additional source of income for growers. Because both the leaves and storage roots can be harvested from the same plant, the crop could provide farmers with two potential food products.
Researchers at Lincoln University of Missouri (LU), Waana Kaluwasha and Safiullah Pathan, investigated the nutritional characteristics of young sweet potato leaves and stems produced under different growing and soil-management practices.
Sweet potato greens are commonly eaten in several Asian and African countries, where tender leaves and stems are prepared in a variety of vegetable dishes. They provide protein, dietary fibre, minerals, essential amino acids and bioactive compounds. However, their use remains limited among consumers and producers in the United States.
“Increasing interest in the nutritional and health benefits of food has prompted researchers to explore non-traditional leafy greens such as SPG,” Pathan said. “A few studies have been done in the United States; however, further research is needed.”
The study compared three varieties — Covington, Murasaki and White Bonita — grown using conventional and organic production methods. Researchers also assessed the impact of a mustard cover crop on nutritional quality.
Overall, conventionally grown greens tended to contain more protein, fibre, fat, minerals and essential amino acids, while organically produced greens showed higher carbohydrate and copper concentrations. The differences between production systems were generally modest.
The mustard cover crop had limited influence on overall nutrient composition but was linked to moderate increases in protein, iron, zinc and certain essential amino acids.
Researchers also found relatively similar nutritional profiles among the three varieties, allowing growers to consider factors such as yield, disease resistance and storage-root performance when selecting varieties.
The findings suggest sweet potato greens could become a useful specialty vegetable and diversify farm revenue. Early-season harvesting of young shoots could be followed by harvesting storage roots later, while the crop’s heat and drought tolerance may offer additional advantages.
“A multi-year, multi-location study across both research field and small-farmer fields, in addition to awareness initiatives, will help popularize SPG as an alternative leafy green vegetable,” the researchers commented.