4 (1) Every grower who sells potatoes in interprovincial or export trade, other than to a dealer or a dealer’s agent, shall
(a) at the end of every calendar month, calculate the total sales of potatoes made by him or on his behalf in interprovincial or export trade; and
(2) Every dealer who buys or receives potatoes from a grower for the purpose of sale in interprovincial or export trade shall
[...]
3 Every grower shall pay to the Commission in respect of potatoes described in an item in Column I of the schedule that are sold in interprovincial or export trade a levy in the amount set out in Column II of that item.
