4 The Commission may, in relation to the powers granted to it by section 3 with respect to the marketing of potatoes in interprovincial and export trade, by order, fix levies or charges and impose them on and collect them from persons described in section 3 who are engaged in the production or marketing of potatoes and for such purposes classify such persons into groups and fix the levies or charges payable by the members of the different groups in different amounts and the Commission may use such levies or charges for its purposes, including the creation of reserves, the payment of expenses and losses resulting from the sale or disposal of potatoes and the equalization or adjustment among producers of potatoes of moneys realized from the sale thereof during such period or periods of time as it may determine.
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