Aspergillus reptans

Aspergillus reptans is a species of mold fungus that serves as a significant pathogen affecting a variety of agricultural products. It is primarily classified as a storage pathogen, meaning it thrives on harvested seeds and grains that are kept in suboptimal conditions. Its presence can lead to severe losses in both grain quality and viability, making it a critical concern for agricultural management.

This fungus exhibits a broad host range, primarily infecting seeds of cereals like wheat, barley, and corn, as well as various oilseeds and legumes. Beyond primary crops, Aspergillus reptans can colonize stored feedstuffs, straw, and organic residues. The ease with which it spreads makes it a persistent threat in silos, granaries, and processing facilities where sanitation measures might be neglected.

The primary symptom of infection is the development of visible mold colonies on the surface of the grain. These colonies often transition from a light, cottony appearance to a darker, olive-green, or black color as spores are produced. Infected seeds often become discolored, brittle, and experience a reduction in germination percentage, as the fungus infiltrates the embryo and endosperm tissues, effectively destroying the seed from within.

The development of Aspergillus reptans is strictly governed by moisture and temperature. High moisture content in grain (above 14-15%) coupled with high ambient humidity provides an ideal environment for rapid colonization. The pathogen is most active at temperatures ranging from +20°C to +30°C. Physical injuries to the seed coat, caused by harvesting equipment or insects, significantly increase susceptibility to fungal attack.

The economic impact of this pathogen is twofold. Firstly, it causes direct yield and quality degradation, leading to seed decay and self-heating within grain bulks. Secondly, Aspergillus reptans is known for producing mycotoxins, which pose serious health risks to both humans and livestock. Preventing its spread is essential to maintain the safety and commercial value of agricultural commodities in storage.

• Drying grain to safe moisture levels (typically below 14%) before storage.
• Implementing regular mechanical aeration in storage facilities to prevent moisture pockets.
• Screening grain to remove debris, dust, and damaged seeds that serve as initial infection points.
• Using appropriate seed treatments (fungicides) during the pre-planting phase.
• Sanitizing storage bins, augers, and equipment before and after each harvest season.