Aspergillus tamarii

Taxonomic position and pathogen nature: Aspergillus tamarii belongs to the kingdom Fungi, phylum Ascomycota, and the genus Aspergillus. It is a cosmopolitan mold fungus that functions as both a saprophyte and a facultative parasite, known for its high enzymatic capacity to degrade plant tissues and store products.

Diseases and affected crops: This fungus primarily causes grain molding and storage rot. It frequently affects cereals such as corn and wheat, as well as oilseeds like soybeans, peanuts, and sunflowers. The infection is characterized by the presence of yellow-brown to olive-green conidial heads that cover the surface of seeds and agricultural commodities.

Biology and life cycle: The fungus spreads through asexual reproduction via conidia. Once the spores land on a suitable substrate, they germinate rapidly to form a mycelial network that infiltrates the plant tissue. The life cycle is driven by the availability of moisture and organic matter, allowing the fungus to propagate quickly in both field and post-harvest environments.

Conditions for development and harmfulness: Aspergillus tamarii thrives in warm, humid conditions with temperatures between 25°C and 35°C. Its impact is severe, leading to decreased seed germination rates, loss of nutritional value in stored grains, and, crucially, the contamination of agricultural products with secondary metabolites, such as kojic acid, which pose significant health risks.

Protection and control measures: Effective management of this pathogen requires stringent post-harvest protocols:

• Immediate drying of harvested grains to moisture levels below the threshold of fungal growth.
• Maintaining optimal storage conditions, including cool temperatures and proper airflow.
• Sanitation of storage facilities to reduce the inoculum load.
• Seed treatment with registered systemic fungicides to protect crops during early growth stages.