ABSTRACT
ABSTRACT Cyanobacteria and algae have attracted much attention because of their potential biotechnological applications. These primary producers are ubiquitous in distribution, possess distinct features of evolutionary signicance, and are the prolic sources of varied biologically active metabolites with potent biomedical and biotechnological applications. This chapter provides insight into the importance of cyanobacteria and algae as biological control agents against many phytopathogens. It is evident that many cyanobacteria and algae produce unique antibacterial and antifungal bioactive metabolites that are eco-friendly and may be suitably applied to the control of phytopathogens. Biological control through the use of microorganisms offers an alternative and attractive approach for disease control without the negative impact of chemicals. Biocontrol agents have become important for sustainable agriculture because they are easy to deliver, may activate plant resistance mechanisms such as systemic/induced resistance, and thereby can indirectly improve plant growth and yields. The comparative efcacy of cyanobacteria and algal extracts against phytopathogens shows that these organisms have future potential as potent biocontrol agents.
