Member States shall restrict access to compensatory payments for rapeseed and colzaseed to any or all of the following categories of seed ... seed of stocks which have an erucic acid content greater than 40 % of the total fatty acid content and for which a cultivation contract was made with an approved first buyer, before sowing, for the production of a crop intended either for a specified non-food use or for use as seed for sowing to produce such a crop ...