Sweet potato spot virus

Pathogen and disease type. The disease is caused by Potyvirus batatamaculae, a member of the Potyviridae family. As a viral pathogen, it interferes with the host plant's physiological functions, systematically colonizing the plant tissues and causing significant metabolic disruption, which ultimately leads to reduced vigor and productivity of the sweet potato crop.

Susceptible crops. The primary host for this pathogen is the sweet potato (Ipomoea batatas). Due to the nature of sweet potato propagation, which typically involves stem cuttings or roots, the virus poses a high risk of being transmitted through systemic colonization of the planting stock. Related species within the Convolvulaceae family may also act as alternative hosts in agricultural landscapes.

Symptoms and signs. Infected plants typically exhibit chlorotic spots, mosaic patterns, and speckling on the leaves. Severe infections can lead to leaf distortion, stunted growth, and general chlorosis. The symptoms are often more pronounced in younger leaves, but as the virus spreads systematically, the entire canopy of the plant can show signs of stress and reduced development.

Conditions for development and spread. The virus is primarily transmitted by aphid species in a non-persistent manner. This means that aphids can acquire and transmit the virus in a very short time frame during feeding. Additionally, the movement of infected plant materials across regions remains the most critical factor for the introduction and long-distance dissemination of Potyvirus batatamaculae.

Economic impact and control measures. The disease causes substantial yield losses, affecting both the quantity and quality of the storage roots. Since there are no curative measures for virus-infected plants, control is strictly preventive. Key strategies include:

• utilizing high-quality, virus-indexed propagation material;
• implementing rigorous aphid control programs;
• practicing strict sanitation by removing diseased plants from the field;
• ensuring adequate spatial isolation between new fields and old, potentially infected crops.