Polyscytalum infection

Polyscytalum is a genus of fungi responsible for significant plant diseases, with Polyscytalum pustulans being the most recognized pathogen in this group. It primarily acts as a soil-borne fungus that targets the subterranean parts of crops, leading to necrotic lesions and skin disorders.

The primary hosts for this pathogen include vegetable crops, particularly potatoes. The fungus exploits wounds on the skin or lenticels to invade the host tissues, where it establishes its mycelium, gradually causing physiological decay and impacting the overall quality of the tubers or root systems.

Symptoms of the infection typically manifest as superficial or deep pustules, brown spots, and irregular ulcers on the surface of the plant organs. In severe cases, the eyes of tubers may become completely necrotic, which severely impairs sprouting and creates entry points for secondary bacterial and fungal pathogens.

Development and spread are favored by cool to moderate temperatures and high soil moisture levels. The pathogen is highly persistent, capable of surviving in the soil debris for extended periods, and can be easily disseminated through contaminated seed stock or infected agricultural machinery moving between fields.

Effective management requires an integrated approach to mitigate the inoculum levels in the soil and protect the planting material.

• Use certified disease-free seed tubers
• Implement long-term crop rotation cycles
• Maintain low humidity levels in storage facilities
• Apply specialized seed treatments prior to planting