Canada to approve phosphorous acid fungicides

The Canadian Pest Management Regulatory Agency (PMRA) has proposed full registration for the sale and use of Winfield Phosphite TGAI, Winfield Phosphite Colorless, Winfield Phosphite Extra, Winfield Phosphite Turf, and Confine Post, containing the active ingredient mono- and di-potassium salts of phosphorous acid, for the control of certain diseases on potatoes; fruiting vegetables; basil; brassica leafy vegetables; leafy vegetables; cucurbits; grapes; ginseng; strawberries; outdoor ornamentals; conifers and trees; and turf grasses.

Mono- and di-potassium salts of phosphorous acid are fungicide active ingredients belonging to Group 33 as designated by the Fungicide Resistance Action Committee and are classified as phosphonates. The mode of action of phosphorous acid is both direct and indirect, and involves the induction of host plant resistance and the inhibition of oxidative phosphorylation.

The PMRA will accept comments on this proposal before 15th November.

Source: Health Canada