Eustigmatales algae

Under conditions of high humidity, the affected areas take on a slimy consistency, which hinders aeration of the topsoil and impairs root gas exchange.

Membranous formations appear on the leaves of low-growing crops or in the root neck area of seedlings, obstructing the normal growth of young plants.

Upon drying, the film can form a hard crust that cracks, leading to mechanical damage to the delicate epidermal tissues of seedlings.

Visually, affected areas often look like "green mold" that suppresses the development of microflora necessary for the nutrition of cultivated plants.

The pathogens are unicellular algae of the order Eustigmatales, capable of active reproduction when the water regime is disrupted.

This is not a disease in the classical fungal sense; however, the excessive growth of these organisms is classified as a negative biotic factor.

Reproduction occurs through zoospores, which quickly colonize available surfaces in the presence of sufficient moisture and sunlight.

These organisms are distinguished by specific pigments that ensure their survival across a wide range of temperatures.

Biologically active substances released during the life cycle of the algae can change the pH of the root zone, inhibiting beneficial symbionts.

The main factor for development is excessive soil moisture, which often occurs when irrigation regimes in greenhouses are poorly managed.

High levels of solar radiation promote intensive photosynthesis in algae, leading to their rapid colonization of all accessible substrate surfaces.

Poor ventilation in greenhouses creates a favorable microclimate with high air humidity, accelerating the spread of spores.

High content of easily available nutrients, especially nitrogen and phosphorus on the soil surface, triggers population outbreaks of these species.

Poor soil structure, prone to compaction and waterlogging, provides an ideal environment for the active vegetation of Eustigmatales algae.

The main damage lies in creating a physical barrier that prevents oxygen from reaching the root system of the cultivated plants.

The algal film absorbs significant amounts of nutrients from the topsoil, competing with crops for essential elements.

Metabolic products of these algae can have a phytotoxic effect, leading to slowed growth rates and chlorosis of seedling leaves.

The presence of algae contributes to favorable conditions for the development of secondary pathogens, including root and stem rots.

In nurseries, the mass development of these organisms leads to the rejection of commercial products due to the loss of decorative and quality characteristics.

The basis of prevention is strict control of the irrigation regime, preventing constant over-saturation of the substrate's top layer.

Regular loosening of the soil is recommended to break the surface crust and improve air access to roots, which suppresses algal growth.

Ensuring high-quality ventilation and airflow in greenhouses significantly reduces air humidity, curbing spore production.

In cases of severe infestation, fungicides with algicidal properties permitted for use on specific crops can be applied.

Prophylactic replacement of the topsoil layer with fresh, coarse-grained substrate prevents the recurrence of algal colonies.