Potential Use of Polyphenolic Compounds Obtained from Olive Mill Waste Waters on Plant Pathogens and Plant Parasitic Nematodes

Phenolic compounds, primarily derived from the phenylpropanoid pathway and acetate pathway are plant secondary metabolites that constitute one of the most common and widespread groups of substances in plants playing an important role in plant resistance. Polyphenols are chemical compounds, belonging in the class of antioxidants, which have attracted extensive attention as natural bioactive materials. Polyphenols are found in plant tissues as well as hazardeous residues after food factory processing olive mill wastes (OMW) which are characterized as phytotoxic and considered a threat to the environment. Thus, there is currently an increasing interest in using of agricultural wastes like Olive Mill Waste Waters-OMWW containing natural polyphenols as non-hazardous organic phytochemical and plant protective substances and substances such us organic matter, minerals, and nutrients. This review article is focuses on the full utilization of OMWW, which are one of the most polluting food industry wastes, in accordance with the principle zero discharge, strategy and most central waste management option. These substances (mainly from the liquid-phase) result to eco-friendly alternatives of chemical pesticides and other agrochemicals and also contribute to the health protection of the farmers and of the consumers. The recovery of high added-value products from waste plant material such as OMWW is therefore a significant issue in non chemical disease control. Several studies worldwide have investigated and proven their bioactivity potential and their effectiveness against various plant pathogens. The development of sustainable strategies based on the reuse of OMW for plant disease control in view to reduce the use of chemical and synthetic pesticides may have considerable economic benefits.