Seed mould

The primary symptom of the disease is the appearance of a loose, powdery coating on the surface of the seeds, which may be white, gray, green, olive, pink, or black, depending on the fungal species.

Infected seeds lose their natural luster, appear dull, and often develop a musty or distinct odor associated with mold. Internal tissue damage often results in the deterioration of starch and proteins.

If infection occurs in the soil after sowing, it leads to a significant decrease in germination energy and laboratory viability. Seedlings often die before emergence or appear weak with necrotic lesions on roots and coleoptiles.

During grain storage, mold causes seeds to clump together, leading to self-heating of the grain pile and eventual rotting or blackening of the germ area.

Visual identification is possible by observing the mycelium and spores, which detach easily from the seed coat, creating dust upon handling. Infected seeds may also become soft and lose their structural integrity.

Seed mold is a collective term for an infectious disease caused by a wide range of fungi (Deuteromycetes). The most common pathogens include species from the genera Aspergillus, Penicillium, Mucor, Rhizopus, Alternaria, Fusarium, and Cladosporium.

These pathogens generally have a saprophytic lifestyle but can act as opportunistic parasites. They are polyphagous, meaning they can infect seeds of almost all agricultural crops, regardless of the species.

These fungi are ubiquitous in the environment, inhabiting soil, plant debris, agricultural equipment, and storage facilities, making them a constant threat to seed health.

Infection can occur in the field under unfavorable weather conditions before harvest, or during post-harvest processing and storage if humidity levels are not properly managed.

They possess a highly efficient enzymatic system, allowing them to rapidly colonize seed tissues and utilize the embryo's energy reserves for their own growth and sporulation.

The key factor in disease development is high moisture content in seeds (above 14–15%) and high ambient humidity. These conditions provide an ideal environment for spore germination and mycelial growth.

Optimal temperatures for most mold-causing fungi range from +15°C to +30°C. However, certain species, particularly from the Penicillium genus, can remain active even at lower temperatures.

Improper post-harvest handling, specifically delays in drying grain, significantly increases the risk of massive mold infestation in stored batches.

Mechanical damage to the seed coat during harvesting or cleaning creates "infection portals," allowing fungal spores to easily penetrate deep into the seed tissues.

Adverse weather conditions before harvest, such as prolonged rain or heavy dew, promote the buildup of fungal inoculum directly on the seeds while they are still in the spikes or pods.

The main impact of seed mold is a severe reduction in seed quality. Infected seeds exhibit poor germination energy and viability, leading to sparse crop stands and the need for costly reseeding.

The disease frequently destroys the seed embryo during storage, rendering the entire seed lot biologically non-viable for sowing.

Fungal metabolic processes produce toxic substances known as mycotoxins, which can be harmful to both human and animal health if the grain is used for food or feed consumption.

Massive development of mold in storage leads to increased respiration, causing self-heating of the grain, which leads to the spoilage of large quantities of grain and significant economic losses.

Seed mold lowers the commercial value of grain, limiting its marketability as it fails to meet the quality standards for milling, baking, or fodder due to protein and starch degradation.

Effective control relies on rigorous agricultural practices: timely harvesting with minimal mechanical damage to the seeds and efficient post-harvest management.

It is critical to dry seeds to safe moisture levels (typically 13–14%) immediately after harvest and to maintain appropriate storage conditions, including proper ventilation and temperature monitoring.

Seed treatment with professional fungicides is an essential preventative measure, as it effectively suppresses both surface and internal fungal pathogens before planting.

Regular phytopathological inspections and viability testing of seed stocks are necessary to identify contaminated batches and remove them from the production cycle.

Using high-quality, clean seeds free of debris and damage significantly minimizes the risk of mold development both in storage and after sowing in the soil.