Common Sweet Potato Plant Diseases:
How to Identify and Treat

Sweet potatoes are a popular and nutritious vegetable that is enjoyed around the world. However, just like any other plant, they are susceptible to various diseases that can hinder their growth and productivity. Being able to identify these diseases early on is crucial in order to implement effective treatment and prevent further spread. In this article, we will discuss some of the most common sweet potato plant diseases, their symptoms, and how to treat them.

1. Sweet Potato Scab

Sweet potato scab is a common disease caused by the fungus called Streptomyces ipomoeae. It is characterized by rough, corky lesions on the surface of sweet potato tubers. These lesions can vary in size and shape but often appear as raised, dark-colored patches that may crack or become scaly.

To treat sweet potato scab, it is important to practice good cultural management practices. Avoid planting sweet potatoes in soil that has a history of scab disease. Additionally, maintaining proper soil moisture levels and avoiding excessive fertilization can help reduce the severity of the disease. If scab symptoms are observed, it may be necessary to apply fungicides labeled for sweet potato scab control.

2. Fusarium Root Rot

Fusarium root rot is caused by the fungus Fusarium solani and is a major concern for sweet potato growers worldwide. This disease affects both the roots and storage roots of sweet potato plants, leading to stunted growth and reduced yield.

Symptoms of Fusarium root rot include wilting, yellowing of leaves, and overall plant decline. Infected roots may exhibit brown discoloration and decay. To manage Fusarium root rot, it is important to start with healthy seedlings and practice crop rotation. Fungicides labeled for Fusarium control may also be used, but prevention through good cultural practices is key.

3. Black Rot

Black rot, caused by the bacterium Xanthomonas campestris pv. campestris, is a destructive disease that affects various cruciferous crops, including sweet potatoes. It is characterized by dark, watery lesions on the leaves, stems, and storage roots of infected plants.

In sweet potatoes, black rot can cause significant yield losses and affect the quality of tubers. To prevent black rot, it is important to plant disease-free seedlings and practice crop rotation. Infected plants should be removed and destroyed to prevent further spread of the bacteria. Copper-based fungicides may also be used to control the disease.

4. Sweet Potato Leaf Curl Virus

Sweet potato leaf curl virus (SPLCV) is a viral disease that is transmitted by whiteflies. It affects the leaves of sweet potato plants, causing curling, yellowing, and stunting of growth. Infected plants may also have reduced tuber production.

Controlling whiteflies is crucial in managing SPLCV. Regular monitoring and early detection of whitefly populations can help prevent virus transmission. Insecticides labeled for whitefly control may be used if necessary. Additionally, practicing good sanitation measures such as removing infected plants and controlling weeds can help reduce disease incidence.

5. Root Knot Nematodes

Root knot nematodes are microscopic roundworms that feed on the roots of sweet potato plants. They cause the formation of galls or knots on the roots, leading to reduced nutrient uptake and stunted growth.

To manage root knot nematodes, it is important to start with nematode-free planting material and practice crop rotation with non-host crops. Soil solarization, a technique that involves covering the soil with a clear plastic sheet to trap heat and kill nematodes, can also be effective. Nematicides may be used as a last resort if nematode populations are high.

In conclusion, sweet potato plants are susceptible to various diseases that can impact their growth and yield. Early identification and implementation of appropriate treatment measures are essential in managing these diseases effectively. By practicing good cultural practices, including crop rotation, proper irrigation, and regular monitoring, sweet potato growers can minimize the impact of these diseases and ensure a healthy crop.