Mucor mucedo

The mycelium of this fungus lacks septa and spreads rapidly, forming a fluffy gray or brownish coating. During development, globose sporangia form on the tips of the hyphae, containing thousands of tiny spores that are easily dispersed by air currents.

The organism is primarily a saprotroph, but in agronomic practice, it acts as an opportunistic pathogen that infects plant tissues with compromised defenses or damaged produce.

This species is a cosmopolitan organism, existing widely in soil, decaying organic matter, manure, and in storage facilities where environmental conditions are poorly managed.

Identification in a laboratory setting relies on microscopic observation: the absence of septa in the mycelium and the presence of dark sporangia allow for accurate classification within the genus.

The fungus affects a wide range of agricultural products, including cereal crops, vegetables, particularly root crops with high sugar content, fruits, and seeds.

Mucor causes the most significant damage during post-harvest storage in closed environments with high humidity. It poses a serious threat to planting material (tubers, bulbs) and grain seeds, reducing their germination capacity.

In field conditions, the fungus can develop on weakened plants, but its primary economic impact is observed in vegetable stores and grain elevators.

Produce infected with Mucor becomes unfit for human consumption due to the accumulation of fungal metabolites, which may possess toxic properties.

The pathogen can also affect livestock feed, presenting risks to animal health, as ingestion of moldy feed may lead to mycotoxicosis in livestock.

Active development of the pathogen occurs during post-harvest processing, transportation, and long-term storage, when favorable microclimatic conditions are present.

Under high humidity (above 85%) and temperatures between 15 and 25 degrees Celsius, the fungus reproduces extremely quickly, covering large areas within a few days.

Seasonal dispersal of spores in field conditions is usually tied to warmer periods, when maturing fruits become highly susceptible to fungal penetration through micro-traumas.

During winter, the fungus survives in the soil and on plant residues in the form of resistant zygospores, which can withstand harsh environmental conditions.

In storage facilities, the season of activity is virtually continuous if proper ventilation is lacking and high moisture levels are maintained.

The first sign of infection is the appearance of white fluffy mycelium, which eventually darkens due to the formation of spores.

Infected plant tissues become soft, watery, and develop a characteristic unpleasant smell of rot, which distinguishes mucor rot from other mold types.

On grain, mucor infection manifests as a dark coating that densely covers the husk, leading to delayed germination or complete loss of seed viability.

In vegetables, the infection often begins at small focal points that gradually expand, turning the plant tissue into a decaying mass.

• Formation of a gray or brown fluffy coating.
• Softening and decay of fruit tissues.
• Presence of a specific moldy odor.
• Reduction in germination energy and seed viability.

The primary control strategy involves strict management of storage conditions: maintaining air humidity below 70% and ensuring efficient ventilation of storage areas.

Before placing produce into storage, it must be thoroughly cleaned of soil particles and damaged units, as these serve as the primary infection points.

It is essential to conduct regular disinfection of storage rooms and containers using approved fungicides to destroy the pathogen's zygospores.

During cultivation, effective pest management is crucial to minimize damage to fruit skins, as any mechanical injury significantly facilitates the entry of Mucor spores.

For seed treatment, the use of fungicidal seed dressings is recommended to create a protective barrier on the seed surface and prevent mold development during the early stages of growth.