Toussoun

Systematic position and nature of the pathogen
The pathogen Fusarium toussoun (synonym Fusarium oxysporum f. sp. toussoun) belongs to the kingdom Fungi, phylum Ascomycota, and genus Fusarium. This phytopathogen is a soil-borne fungus capable of persisting in the substrate for long periods and infecting the vascular system of plants, causing systemic vascular diseases.

Diseases and host crops
This pathogen is a causative agent of fusarium wilt (tracheomycosis) and root rots. The list of host crops primarily includes cereal crops, corn, as well as vegetables such as tomatoes and legumes. The infection attacks the root system, disrupting the normal upward transport of water and nutrients within the plant.

Biology and life cycle
The fungus spreads through infected seeds, plant debris, and soil. Its life cycle includes the formation of microconidia, macroconidia, and chlamydospores, which ensure the fungus survives under unfavorable conditions. The pathogen enters the plant through root hairs or micro-injuries, after which fungal hyphae colonize the plant's xylem.

Development conditions and economic impact
Development of the disease is favored by high soil moisture and temperatures in the 20–25°C range. The harmfulness manifests as loss of turgor, yellowing, and subsequent plant death. Massive infection of fields can lead to yield losses of 30–50%, and in years favorable for the pathogen, it can result in a total loss of commercial quality of the harvest.

Protection and control measures
To manage Fusarium toussoun, a comprehensive approach is recommended, including:

• Using healthy, fungicide-treated planting material.
• Implementing crop rotation to exclude susceptible crops for 3-4 years.
• Applying balanced fertilizers and monitoring soil pH levels.
• Managing crop residues and using deep fall plowing to limit the accumulation of inoculum in the soil.