Sweet potato (as a pathogen host)

Sweet potato (Ipomoea batatas), belonging to the Convolvulaceae family, plays a significant role in plant pathology as a primary host for various viral, fungal, and phytoplasmal pathogens. Because it is propagated vegetatively, the plant often acts as a long-term reservoir for infections that can persist through generations of tubers, making it a critical focus for disease management programs.

The main diseases associated with sweet potato include the Sweet Potato Feathery Mottle Virus (SPFMV), Fusarium wilt (Fusarium oxysporum), and bacterial soft rot. These pathogens infiltrate the plant tissue systemically. Once the plant is infected, the pathogen is distributed throughout the stems and tubers, ensuring that any cuttings or tubers taken from infected plants will carry the disease into new fields.

The biology of these pathogens varies: viruses rely heavily on insect vectors such as aphids and whiteflies to spread within and between fields, while fungal pathogens are often soil-borne or originate from contaminated storage environments. The developmental cycle of these pathogens is often synchronized with the host's growth stages, with infection severity peaking during periods of high physiological activity or plant stress.

Environmental conditions such as high soil moisture and temperatures ranging from 25°C to 30°C create an optimal environment for the proliferation of fungal pathogens like Fusarium. Furthermore, the lack of crop rotation and the failure to remove infected plant debris serve as primary drivers for the rapid spread and establishment of these disease complexes in the soil, which can persist for years.

The economic impact of these pathogens is severe, often resulting in significant yield reduction, tuber decay, and complete loss of crop quality. Effective management strategies involve the exclusive use of certified virus-indexed planting material, integrated pest management (IPM) to control vectors, strict hygiene during harvest and storage, and a robust crop rotation plan to break the pathogen's life cycle.