Cylindrospermum licheniforme

Cylindrospermum licheniforme is a species of nitrogen-fixing cyanobacteria that often colonizes waterlogged soils. While these organisms are natural contributors to soil nitrogen cycles, their excessive proliferation can create physical barriers on the soil surface, negatively impacting commercial agricultural crops.

The primary crops affected by this organism are rice grown in flooded paddies and various potted plants in greenhouse environments. In these conditions, the cyanobacteria can quickly cover the substrate surface, creating an anaerobic layer that hinders root respiration and promotes the development of secondary pathogenic fungi.

The characteristic symptoms include the formation of dark green to brownish slimy mats on the soil surface. Once the water level recedes or the surface dries out, these mats transform into brittle, hard crusts that block oxygen exchange and restrict the emergence of young seedlings.

The development of Cylindrospermum licheniforme is driven by high humidity, stagnant water, and elevated temperatures, combined with nutrient-rich soil. In greenhouses, poor ventilation and overwatering are the main factors that facilitate the rapid colonization of cultivation media by these cyanobacterial mats.

Effective management strategies focus primarily on water management. By improving drainage and avoiding constant saturation of the soil, the growth conditions for the cyanobacteria are effectively eliminated. Additionally, physical disruption of the surface crust through cultivation and, in severe cases, the application of targeted algaecides can help suppress population levels and protect the crop.

Maintaining a balanced soil chemistry and proper ventilation in greenhouses are crucial for preventing the establishment of these colonies. Regular monitoring of moisture levels is the most critical agronomic practice to prevent the negative effects associated with this species on plant growth and development.