Sweet potato

Sweet potato (Ipomoea batatas) is a host plant for numerous soil-borne and airborne pathogens. In agricultural practice, managing these phytopathogens is crucial, as they directly impact the yield, quality, and storage life of the storage roots, often causing significant losses to growers.

Key pathogens include Fusarium oxysporum, which causes vascular wilt, and Ceratocystis fimbriata, the agent of black rot. These organisms attack various plant parts, from roots and stems to the harvested tubers, leading to necrosis, tissue softening, and total plant collapse under favorable conditions.

The biology and lifecycle of these pathogens are typically soil-dependent. They survive as resting structures such as chlamydospores or sclerotia within crop residues. When favorable conditions—such as high soil moisture and moderate temperatures—occur, they germinate and penetrate the host tissue through natural openings or wounds.

Environmental conditions are the primary drivers of disease outbreaks. Poor drainage, heavy soil compaction, and prolonged rainfall facilitate the spread of fungal and bacterial pathogens. Furthermore, improper handling during harvesting, which leaves wounds on the periderm, makes tubers highly susceptible to secondary infections in storage.

Control strategies must be integrated. Effective measures include using certified disease-free "slips" (cuttings), implementing a strict crop rotation schedule to break the pathogen's lifecycle, and sanitizing storage facilities. Maintaining optimal post-harvest curing conditions is also vital to allow the skin to heal, effectively blocking entry points for pathogens.