Penicillium rot

Penicillium citrinum is a common filamentous fungus known for its significant impact as a post-harvest pathogen and a storage mold. As a versatile saprotroph, it can easily colonize weakened or damaged plant materials, causing physiological decay and biochemical degradation of seeds, fruits, and stored agricultural products.

This pathogen affects a vast range of crops, primarily targeting cereals, maize, legumes, and various fruit species. Its agricultural significance is largely defined by its ability to cause severe damage to stored commodities, leading to substantial economic losses by reducing both the quantity and the nutritional quality of the harvest.

The hallmark symptoms of infection include the appearance of a dusty, blue-green or grey-green mold layer on the affected surfaces. In seeds, the fungus penetrates the embryo, causing softening of tissues, a musty odor, and a complete loss of germination potential. In fruit, it leads to rapid tissue breakdown and the development of watery rot pockets.

Environmental conditions are the primary drivers of Penicillium citrinum development. The fungus thrives in environments with relative humidity levels exceeding 75% and temperatures ranging from 20°C to 25°C. Poor ventilation in storage facilities and the presence of physical injuries on the harvest serve as ideal entry points for spores, leading to rapid contamination across entire batches.

Beyond physical damage, the fungus is known to produce the mycotoxin citrinin, which poses significant health risks to both humans and livestock if contaminated feed or grain enters the food chain. Management strategies must prioritize strict moisture control in stored products, regular cleaning and sterilization of storage facilities, and the application of effective fungicidal seed treatments to prevent field-to-storage infection cycles.