Sweet potato

Sweet potato (Ipomoea batatas) is a vital global food crop that is unfortunately susceptible to a wide array of pathogens. While it is not a pathogen itself, understanding the diseases that affect this plant is essential for modern agronomists to minimize losses and ensure food security. The interaction between Ipomoea batatas and its pathogens defines the success of the agricultural cycle.

Taxonomically, the crop belongs to the Convolvulaceae family. The most common phytopathogens affecting it include the fungus Fusarium oxysporum (causing vascular wilt), Plenodomus enteroleucus (foot rot), and Ceratocystis fimbriata (black rot). Furthermore, viral complexes like the Sweet Potato Feathery Mottle Virus (SPFMV) significantly impact the plant's vigor and yield quality.

The biology and lifecycle of these pathogens vary; for instance, soil-borne fungi persist in debris for several seasons, while viruses are systemic and persist in the tubers. Infection usually occurs through soil contact, wounding during harvest, or via insect vectors such as aphids and whiteflies. Once inside the vascular system or parenchyma, these pathogens rapidly consume the plant's nutrients.

Environmental factors play a crucial role in disease dissemination. High humidity and poor soil drainage are the primary catalysts for root rot development. Conversely, warm and dry conditions during the vegetative stage may favor the spread of certain viral diseases transmitted by insects. Once the storage phase begins, improper ventilation can lead to total crop destruction within a short period.

Effective management and control require a multi-faceted approach to mitigate damage:

• Utilizing disease-indexed or virus-free planting stock.
• Implementing long-term crop rotation to break pathogen lifecycles.
• Applying recommended fungicides as seed treatments before storage.
• Practicing strict hygiene during the harvesting process to prevent wounding.