Fusarium wilt of sweet potato

The disease is caused by the fungus Fusarium bataticola, an soil-borne pathogen known for causing vascular wilt in sweet potatoes. By colonizing the xylem vessels, the fungus disrupts the transport of water and essential nutrients, leading to premature wilting and, eventually, the death of the plant. The fungus is highly resilient and can persist in the soil for several years.

The primary host for this pathogen is the sweet potato (*Ipomoea batatas*). It impacts cultivation in both tropical and subtropical regions. Because the fungus thrives in the root zone, it is often difficult to eradicate once it has established in a field, making soil health and prevention strategies essential for long-term agricultural success.

Symptoms typically begin with yellowing and chlorosis of the lower leaves, followed by wilting that progresses upward. Affected plants often display stunted growth and a reduced number of storage roots. A diagnostic cross-section of the stem or root reveals a distinct brown discoloration of the vascular ring, which is a hallmark of the fungal infection.

The development of the disease is favored by warm, humid conditions, specifically with soil temperatures ranging between 25°C and 30°C. Spread occurs through contaminated planting material, movement of soil by farm equipment, and the flow of irrigation water. Poor drainage conditions further exacerbate the risk of a widespread outbreak within a field.

• Use disease-free, certified slips or planting cuttings.
• Implement a strict crop rotation cycle of at least 3 years.
• Ensure proper field drainage to prevent waterlogged conditions.
• Remove and burn any symptomatic plants immediately upon detection.
• Apply soil amendments to maintain optimal soil pH levels.

The economic impact of Fusarium bataticola is significant, often resulting in complete yield failure in heavily infested fields. Furthermore, tubers harvested from infected plants often exhibit poor post-harvest durability, as they become highly susceptible to secondary rots in storage. Effective management relies on an integrated approach focusing on prevention and the use of resistant varieties.