Dry rot of root crops

Dry rot of root crops is a severe fungal disease primarily caused by various species of the Fusarium genus. This pathogen is notorious for causing significant postharvest losses, often turning healthy-looking produce into decayed material during long-term storage in warehouses and cellars.

This disease targets a wide range of root crops, including potatoes, sugar beets, carrots, and turnips. The fungus is soil-borne, meaning it survives in the field for years as dormant spores or within plant debris. Consequently, once a field is contaminated, the risk of infection remains persistent for subsequent cropping seasons.

The visual symptoms typically appear as shrunken, brownish, or dark-colored lesions on the skin of the root crop. As the infection progresses, the internal tissue becomes dry, powdery, and corky. In many cases, deep voids form within the root, frequently lined with white, pink, or light-yellow fungal spores, confirming the presence of the pathogen.

Conditions favorable for the development of dry rot include high soil moisture during the growing season and poor handling during harvest. Mechanical injuries, such as cuts and bruises occurring during harvesting or transportation, provide ideal entry points for the fungal spores, allowing them to penetrate deep into the root tissues.

Effective control strategies require a combination of preventative field practices and postharvest care. Key measures include rotating crops, minimizing mechanical damage during harvest, and ensuring that produce is properly cured before storage. Additionally, maintaining a cool and well-ventilated storage environment, along with the use of appropriate fungicides on seeds, significantly reduces the disease pressure.