Fragilariales algae

Fragilariales is an order of diatom algae that, while not acting as a traditional plant pathogen, poses a significant threat to greenhouse crops, hydroponics, and aquatic agricultural systems. These microorganisms aggregate into complex colonies that can encrust plant surfaces, causing severe physiological stress.

These organisms are characterized by silicified cell walls that allow them to attach firmly to solid surfaces. In agricultural settings, they compete for nutrients and light, essentially choking the plant’s roots and limiting the gas exchange necessary for healthy development and nutrient uptake from the root zone.

Plants at risk include those cultivated in hydroponic setups, water-grown crops like rice, and nursery seedlings kept under high-humidity conditions. The presence of these algae is often an indicator of nutrient imbalance or poor water quality management within the growing environment.

Symptoms include the formation of a fuzzy brown, rusty, or greenish-brown film on roots or the surface of growing media. Affected plants typically show signs of stunted growth, leaf chlorosis, and wilting, as the algae physically prevent the roots from accessing sufficient oxygen and mineral solutions.

Development is accelerated by excessive exposure to light and high nutrient concentrations in irrigation water.

• Implementing strict light management in hydroponics.
• Using UV water sterilizers.
• Regular cleaning of nutrient tanks and reservoirs.
• Balancing nutrient levels to prevent runoff.
• Ensuring proper water circulation.