Aspergillus terreus

Aspergillus terreus is a filamentous fungus often found in soil that functions as a facultative plant pathogen. While primarily known as a saprophyte, it can infect various crops under stress, particularly in post-harvest environments. It is characterized by its distinct cinnamon-brown spore colonies and its ability to secrete bioactive compounds.

This pathogen commonly attacks a wide range of crops, including wheat, maize, and legumes. It is especially notorious for infecting seeds and stored grain, leading to significant economic losses. The fungus spreads rapidly in bulk storage, compromising the quality and safety of agricultural commodities by producing harmful mycotoxins.

Symptoms of infection include the appearance of dense, powdery fungal growth on the surface of seeds, pods, or stems. When seeds are infected before germination, the pathogen leads to "damping-off," where the seedling dies shortly after emergence due to tissue necrosis at the base of the stem or root system.

The development of the disease is strictly dependent on environmental factors, specifically high relative humidity (above 70%) and warm temperatures (25–35°C). The fungus exploits micro-cracks in seed coats caused by pests or mechanical damage to invade deep tissues. Spores are easily disseminated via wind and contaminated equipment.

Management strategies focus on prevention and sanitation. Recommended practices include:

• Using high-quality, fungicide-treated seeds.
• Drying harvested grain to moisture levels below 14%.
• Maintaining well-ventilated, cool storage facilities.
• Implementing integrated pest management to reduce mechanical damage to grain.