2018—Subsec. (a). Pub. L. 115–334 substituted “, tuber propagated, or asexually reproduced” for “or tuber propagated” in introductory provisions.

1996—Subsec. (a)(1)(B)(i). Pub. L. 104–127 inserted “, except that in the case of a tuber propagated plant variety the Secretary may waive the 4-year limitation for a period ending 1 year after April 4, 1996” after “filing”.

1994—Pub. L. 103–349 amended section generally, substituting present provisions for substantially similar former provisions.

Amendment by Pub. L. 103–349 effective 180 days after Oct. 6, 1994, see section 15 of Pub. L. 103–349, set out as a note under section 2401 of this title.