Aspergillus oryzae

Systematic position and nature of the pathogen: Aspergillus oryzae belongs to the kingdom Fungi and the genus Aspergillus. While industrially significant for fermentation processes, in an agronomic context, it is recognized as a facultative parasite and a common post-harvest pathogen that degrades plant material and causes deterioration in storage.

Diseases and susceptible crops: This fungus primarily affects the seeds and grains of major crops, including rice, wheat, corn, and soybeans. It is a major cause of grain mold in storage facilities, leading to heating, discoloration, and a characteristic musty odor that signals the loss of quality and safety of the stored product.

Biology and life cycle: The fungus reproduces via asexual spores known as conidia, which are highly resilient and easily dispersed by air currents. Once they land on a suitable substrate with sufficient moisture, the conidia germinate, producing hyphae that penetrate the grain, utilizing stored nutrients for rapid growth and colonization.

Conditions for development and harmfulness: The development of Aspergillus oryzae is highly dependent on environmental factors, specifically moisture levels exceeding 14-15% and temperatures between 25°C and 35°C. Its harmfulness stems from the destruction of seed embryos, leading to loss of germination capacity, reduced grain mass, and the accumulation of potentially toxic metabolites.

Protection and control measures: Effective management relies on strictly controlled storage environments and preventive hygiene:

• Thorough cleaning and drying of grain to reduce moisture content below critical levels.
• Utilization of automated ventilation and cooling systems in grain silos.
• Routine inspection and monitoring of moisture and temperature markers within the bulk grain.
• Implementation of warehouse sanitation protocols, including the use of approved antifungal treatments to sanitize storage facilities.