Biochemical Biopesticides: Organic Acids

Peracids are highly effective sanitizing agents used for control of pathogens and algae.  Peracids, also called activated peroxygen, use hydrogen peroxide (H2O2) as their base component. Hydrogen peroxide is a well-known chemical compound that can be found in most people’s medicine cabinets for disinfecting cuts and bruises, among other uses.
Peracids combine hydrogen peroxide and organic acids, typically acetic acid, to form a new compound called peroxyacetic acid, abbreviated as PAA. This new compound is an activated form of hydrogen peroxide and produces a much more stable and powerful oxidizing compound to treat pathogens and algae in water.

The mode of action of peracids is by oxidation of cell membranes and penetration into cell structures of algae, bacteria and fungi. More specifically, peracids form free hydroxyl radicals (OH), which oxidize and disrupt thiol groups in proteins and enzymes.

Several features make peracids an excellent choice for agricultural and horticultural water treatment. First, peracid products that have been specifically formulated for horticulture offer a high degree of safety with regard to phytotoxicity.  With formulated peracids, the grower can easily adjust the concentration of active ingredient in the treated water to account for increased biological loading.  This is important since some organisms are easily susceptible even at low levels of peracids whereas others such as Pythium require higher active ingredient levels.  Peracid products can be used for sanitation of greenhouse surfaces, shock applications for tanks and piping, continuous application at a low concentration, and also as a bactericidal or fungicidal application to plant foliage or roots. A further advantage is that when peracids degrade, the byproduct is oxygen, which is safe and beneficial .