Fenton as advanced oxidation process for controlling downy mildew of cucumber under greenhouse conditions

In this research, the curative action of Fenton reagent (H_2O_2)/Fe(2+)), Fenton like reagent (H_2O_2)/Fe(3+)), Fenton complex (H_2O_2)/Fe(3+)/oxalic acid) and famoxadone + cymoxanil as foliar applications were examined against downy mildew of cucumber caused by Pseudoperonospora cubensis (Berk. and Curtis) under greenhouse conditions during two successive growing seasons. Likewise, the impact of these treatments was also investigated on some biochemical and growth characters of cucumber plants. In addition the toxicity of Fenton solutions were assessed on rats as for biochemical and histological changes in liver and kidney of treated rats with respect to control. Results demonstrated that famoxadone + cymoxanil was the best treatment against downy mildew followed by Fenton like reagent, Fenton reagent and Fenton complex, in both growing seasons. There was marked increase in each biochemical parameter of cucumber plants (chlorophyll, peroxidase and polyphenoloxidase) and also in cucumber yield under all treatments compared to untreated control. No noticeable alterations were observed in liver and kidney of rats treated with the tested Fenton solutions compared to control. Fenton solutions could be utilized as efficient and safe means to control downy mildew of cucumber in greenhouse conditions.