Mucor rot

Mucor rot is a significant post-harvest disease caused by the fungus Mucor mucedo. This pathogen is a fast-growing saprophyte that predominantly targets harvested produce, exploiting mechanical injuries or weak points in the plant tissue. It is particularly notorious for its ability to spread rapidly in storage environments where hygiene or ventilation is inadequate.

The fungus affects a diverse range of crops, with strawberries being one of the most susceptible hosts, alongside various berries, stone fruits, and succulent vegetables. Because Mucor mucedo is ubiquitous in the environment, it can easily contaminate produce from the soil, through contaminated water, or via dirty harvest equipment and storage containers.

The primary symptom of the disease is a soft, watery decay of the plant tissues, often accompanied by a distinct, unpleasant yeasty or fermented odor. As the infection progresses, the surface of the fruit becomes covered in a dense, fluffy white or greyish mold mat. As the fungal spores mature, this growth turns dark grey or black, signaling that millions of new spores are being released into the immediate environment.

Development and spread are facilitated by high humidity and moderate temperatures. Under such conditions, the fungus can complete its life cycle in a very short time, leading to total loss of the infected produce. Because the spores are airborne and highly resilient to environmental stress, they can persist on storage walls, wooden crates, and sorting belts, posing a recurring threat to subsequent batches of fresh produce.

Effective management of Mucor rot relies heavily on preventive agricultural practices to minimize the inoculum load. The following measures are crucial for protecting the harvest:

• Strict hygiene protocols in packing houses and storage facilities.
• Immediate cooling of harvested produce to reduce metabolic activity and pathogen growth.
• Avoiding mechanical damage to fruits during harvesting and transportation.
• Systematic removal of decaying fruit to prevent nest-like infection patterns.
• Application of approved post-harvest treatments and effective ventilation systems.