Penicillium rot

The causal agent of this disease is the microscopic mold fungus Penicillium viridicatum, which belongs to the group of imperfect fungi. It is a typical saprophyte that can manifest pathogenic properties under specific environmental conditions, causing significant degradation of agricultural products. The disease is classified as mold or storage rot affecting seeds and fruit tissues.

The primary hosts of this pathogen are cereal and legume crops, including wheat, barley, and corn, as well as various fruit and vegetable products. The fungus is particularly dangerous to grain stored with high moisture content, as it colonizes the intergranular space and penetrates deep into the embryo and endosperm of the seeds.

Symptoms of the infection manifest as a characteristic blue-green or gray-green powdery bloom on the surface of seeds or fruits. As the mycelium develops, the tissue darkens, becomes spongy, and develops a distinct musty odor. In cases of severe infection, the grain clumps together, indicating deep penetration of the fungal hyphae.

Development of Penicillium viridicatum is facilitated by high grain moisture levels (above 15-16%) and elevated temperatures in storage facilities. The fungus spreads via conidia, which are easily carried by air currents, dust, or storage pests. Poor ventilation and inadequate temperature management are the primary drivers of large-scale infection outbreaks.

The harmfulness of this fungus stems not only from reduced seed germination and aesthetic damage but also from the accumulation of hazardous secondary metabolites known as mycotoxins, specifically ochratoxins and citrinin. Consumption of contaminated products by humans or animals poses a major health risk, as these substances are known for their significant nephrotoxic effects.

• Maintain grain moisture levels at 13-14% or lower during storage.
• Perform regular cleaning and disinfection of storage facilities.
• Monitor temperature levels within grain bins and silos.
• Apply appropriate fungicidal treatments to seed stock.
• Implement strict control measures against storage pests to prevent spore spread.