Section 14. Membership in such corporations shall be limited to persons engaged in the production of products which are handled or to be handled by the corporation, as specified in its articles of organization, including the lessees or tenants of land used for the production of such products and lessors or landlords to whom are due all or any part of such products produced on leased or rented premises in payment for the use of such premises. If a member is a corporation, it may be represented by any officer thereof, duly authorized in writing.