Aspergillus flavus

Taxonomic position and nature of the pathogen: Aspergillus flavus (a major pathogen often associated with Indian peanut crops) belongs to the kingdom Fungi, phylum Ascomycota, and genus Aspergillus. It is a cosmopolitan soil fungus recognized primarily for its role as a destructive plant pathogen and a prolific producer of secondary metabolites.

Diseases and host plants: This fungus is the primary cause of yellow mold and storage rot. It affects a wide range of economically important crops, including peanuts, maize, cottonseed, and various tree nuts. Infection can occur both in the field during the growing season and post-harvest during storage and transport.

Biology and life cycle: The life cycle is characterized by the production of abundant asexual spores called conidia, which are easily dispersed by wind and insect vectors. The fungus exists saprophytically in soil, surviving on decaying organic matter, but becomes parasitic when it encounters host plants that are weakened or mechanically damaged.

Developmental conditions and harmfulness: The pathogen thrives under warm (25–35°C) and humid conditions. Its main threat is the production of aflatoxins, which are highly toxic and carcinogenic compounds. Contamination by these toxins leads to the rejection of agricultural commodities in international trade and poses a severe health risk to both humans and livestock.

Protection and control measures: Effective management requires an integrated approach to mitigate the risk of contamination:

• Implementing proper crop rotation and soil management practices.
• Managing irrigation to prevent drought stress, which predisposes peanuts to infection.
• Harvesting crops at the appropriate maturity stage to minimize field damage.
• Maintaining low moisture content and adequate aeration in storage facilities to inhibit fungal growth.