Chromulinales algae

Chromulinales constitute an order of golden algae that can act as opportunistic colonizers in agricultural settings, particularly within hydroponic and aquaponic systems. While not traditional plant pathogens, their presence creates a biological film that competes with the host plant for space and resources.

These organisms primarily affect greenhouse-grown crops, including leafy greens and seedlings, where high humidity and light availability coincide. The algae attach to stems, leaves, and the root-zone surfaces, disrupting the normal physiological processes of the plants by clogging surface pores and hindering gas exchange.

Symptoms of infestation are identified by a visible yellow, brown, or golden-colored surface layer. This coating can vary from a dry powdery texture to a wet, slimy film. If left untreated, the covering reduces photosynthetic efficiency, which leads to stunted growth, yellowing (chlorosis) of the foliage, and increased susceptibility to opportunistic bacterial infections.

The proliferation of Chromulinales is driven by high light exposure in nutrient-rich environments. In greenhouse production, light leakage into the nutrient solution tanks is the most common cause of rapid blooms. These algae thrive in oxygenated water containing excess minerals, making controlled environment agriculture (CEA) particularly vulnerable.

Effective prevention and control include rigorous sanitation protocols for all equipment and reservoirs. Growers should utilize opaque materials for nutrient delivery systems to eliminate light penetration. Additionally, implementing UV sterilization for recirculating water systems and maintaining proper nutrient balances can significantly inhibit the development and spread of these golden algae.