Repeal effective on the one hundred and eightieth day after Aug. 9, 1939, except that notices with respect to imported alfalfa and red clover seed promulgated by the Secretary of Agriculture under authority of former sections 111 to 116 of this title, which were in effect Aug. 9, 1939, remained in full force and effect as if promulgated under sections 1551 to 1610 of this title.