Calothrix pulvinata

Calothrix pulvinata is a species of filamentous cyanobacteria that occasionally acts as an invasive organism in agricultural aquatic systems. While often found in natural habitats, it can colonize irrigated crops, creating dense mats that impact the physiological health of plants by competing for nutrients and physical space.

The primary crops affected by this organism are flooded rice and various hydroponically grown vegetables. The accumulation of these cyanobacteria on stems and leaves creates a physical film that significantly reduces the efficiency of gas exchange and light interception, which are essential for normal development.

Symptoms of infestation typically include the emergence of small, dark-colored, cushion-like clusters on the plant surface or submerged soil. These mats can harden over time, causing mechanical damage to tender plant tissues and creating a microenvironment that facilitates the spread of other aquatic pathogens.

The development of Calothrix pulvinata is accelerated by high light intensity, warm water temperatures, and eutrophication (excess of phosphorus and nitrogen). Stagnant water bodies are the most susceptible, as they allow the organism to rapidly multiply and establish large colonies across the field surface.

To protect agricultural production, the following management and prevention strategies should be implemented:

• Regular monitoring of water chemistry to prevent nutrient overloading.
• Maintaining water flow or periodic drainage to disrupt the life cycle of the algae.
• Using appropriate algicides at the early stages of infestation to prevent mass growth.
• Integrating cultural practices that increase shading to limit the light available for algal photosynthesis.