Pseudanabaenales

Pseudanabaenales is an order of filamentous cyanobacteria that, in agricultural environments, are often associated with the growth of harmful algal biofilms. While not traditional plant pathogens, their massive colonization of substrates can lead to severe physiological stress in crops, hindering optimal development and yield.

These organisms primarily affect crops grown under high-moisture regimes, including hydroponic systems, vertical farming, and rice cultivation. They are known for their ability to form dense, slimy mats on growing media, soil surfaces, and even the root systems of young plants in nursery settings.

Common symptoms include the appearance of a visible blue-green, slippery layer on the cultivation surface. This layer effectively creates a physical barrier that restricts gas exchange (oxygen uptake) for the roots, leading to anaerobic conditions in the rhizosphere, which subsequently triggers root rot and nutrient deficiency symptoms.

The development of Pseudanabaenales is heavily influenced by high light intensity, high humidity, and an excess of nitrogen or phosphorus in irrigation water. These conditions provide an ideal environment for rapid cell division, allowing the algae to outcompete crops for available nutrients and space, particularly in recirculating systems.

Control strategies focus on preventing bloom through better management of environmental factors:

• Regular monitoring and cleaning of irrigation lines.
• Optimizing fertilizer concentrations to prevent nutrient runoff.
• Implementing proper ventilation to manage surface moisture.
• Using appropriate algaecides or biological control agents when necessary.