Blue-green algae, also known as cyanobacteria, are oxygen-producing organisms that often overproduce when present in favorable environments. Uncensored reproduction can lead to nitrogen runoff, especially when introduced into fertilizer. Cyanobacteria release natural chemicals that can be toxic to plants and lead to distorted development in plants and animals that ingest the chemicals.
Cyanobacteria are toxic to plants, inducing negative responses and triggering dangerous physiological processes. Research that has delved into the subject of protecting food crops from the effects of cyanobacterial poisoning hasn't yielded many results, and as of 2010, further research is needed.
Cyanobacterial toxins have been found to inhibit seed germination rates. The amount of reduction in plant germination varies with species of the plants, but no known plants are completely resistant to poisoning from blue-green algae.
Cyanobacteria that make their way into fertilizer release cyanotoxins that inhibit protein phosphates within plants. The protein phosphate enzymes are needed to regulate nitrogen and carbon synthesis but are forced to slow their processes when poisoned by algae toxins. Some plants can counter the effects of cyanotoxins, but as the algae begin to reproduce, the plant becomes more and more stressed.
Cyanobacterial toxins present in fertilizer are absorbed into plants. As they are absorbed, free radicals are created. Free radicals will begin to degrade within the plant, oxidizing plant lipids and destroying the plant on a cellular level. There is no known cure for cyanobacterial toxicity, but damage can be limited by continued irrigation with clean, uncontaminated water.
Lowered synthesis rates will alter and reduce the development of the plant. This can lead to decreased fruit production, slowed growth and diminished seeds germination. Cyanobacteria are sometimes introduced to fertilizer through irrigation, spreading terrestrially and causing widespread damage.