Saccharomycetes

These fungi are single-celled organisms that propagate via budding. Unlike filamentous fungi, they do not develop a true mycelium, which allows them to colonize plant tissues with high speed.

Their pathogenicity stems from their ability to metabolize sugars, converting them into ethanol and carbon dioxide. This metabolic activity leads to rapid decay and loss of quality in carbohydrate-rich plant products.

Transmission occurs through water splashes, insect vectors, and contaminated agricultural tools. These microorganisms are ubiquitous in the environment, residing on the surface of healthy tissues.

For infection to occur, the pathogen must penetrate the plant through existing micro-wounds or physiological ruptures in the skin of fruits and berries.

The primary symptom of a Saccharomycetes infection is the softening of fruit tissues, accompanied by a distinct acidic or alcoholic odor, characteristic of fermentation.

Visible symptoms often include the release of gas bubbles and exudate on the surface of the fruit. The interior of the fruit turns watery and darkens significantly.

Unlike many other fungal pathogens, Saccharomycetes rarely produce a visible fuzzy mycelial layer on the fruit surface. Instead, the focus is on the structural degradation of the pulp.

Due to the destruction of cellular integrity, the fruit loses its shape and may begin to leak its juices. This structural collapse makes the fruit extremely susceptible to secondary infection.

Affected fruits often attract fruit flies (Drosophila), which act as secondary vectors, accelerating the spread of the infection to healthy parts of the crop.

High humidity and the presence of surface moisture (condensate) are the most critical factors for the development of the disease. Proper aeration is essential to prevent such conditions.

The optimal temperature for rapid fermentation ranges from +20°C to +30°C. In these conditions, yeast cells multiply exponentially, causing severe damage within a short timeframe.

Mechanical damage is a prerequisite for primary infection. Bruises, insect bites, or cracks caused by over-ripening serve as direct entry points for the yeast cells.

Poor ventilation in storage facilities leads to the accumulation of carbon dioxide and moisture, creating a perfect environment for the uncontrolled growth of these fungi.

Over-ripeness, characterized by a high sugar content, makes the crop significantly more vulnerable, as the yeast finds an abundance of accessible energy sources for rapid colonization.

The harm caused by Saccharomycetes results in the total loss of marketability and nutritional value of the produce. Fermentation processes irreversibly destroy the quality of fruits.

The disease triggers a secondary cascade of infections, including bacterial rot, which rapidly leads to the complete destruction of the harvested batch during storage.

Economic damage includes direct crop loss, increased labor costs for sorting damaged produce, and the expense of disposing of contaminated material.

Products of fermentation render the fruits unsuitable for processing into juices, jams, or preserves due to off-flavors and undesirable chemical changes.

The speed of the disease progress often leads to widespread contamination during transit, resulting in significant post-harvest logistics losses.

The primary preventive measure is to ensure careful harvesting procedures, avoiding mechanical injuries that could compromise the skin of the fruits.

Maintaining proper ventilation in warehouses helps reduce air humidity and prevents condensation, which is crucial for stalling pathogen activity.

Sanitizing storage containers and facilities before the harvest season is mandatory to reduce the initial load of yeast spores in the environment.

• Rigorous sorting of fruits before packing.
• Pest management throughout the growing season.
• Rapid cooling of the produce immediately after harvest.
• Use of clean, dry packaging materials.

Applying preventive fungicide sprays during the vegetative phase can reduce the risk of primary fruit infection by protecting the skin surface from colonization.