agricultural land do not occur or are incidental. (ii) Incidental sales For purposes of clause (i), commercial sales described in that clause are incidental if the sales are less than 25 percent of the gross sales of the primary product of the testing, development, or production of public seed varieties or plants for sale or resale to farmers as seed stock carried out on the agricultural land. (3) Land acquired by law For purposes of paragraph (1)(E)— (A) the 5-year period described in that paragraph shall be a covenant running with the title to the agricultural land against any grantee, assignee, or successor of the legal entity