§ 2562. Presumption of validity; defenses

(a) Certificates of plant variety protection shall be presumed valid. The burden of establishing invalidity of a plant variety protection shall rest on the party asserting invalidity.

(b) The following shall be defenses in any action charging infringement and shall be pleaded:

(1) noninfringement, absence of liability for infringement, or unenforceability;

(2) invalidity of the plant variety protection in suit on any ground specified in section 2402 of this title as a condition for protectability;

(3) invalidity of the plant variety protection in suit for failure to comply with any requirement of section 2422 of this title;

(4) that the asserted infringement was performed under an existing certificate adverse to that asserted and prior to notice of the infringement; and

(5) any other fact or act made a defense by this chapter.

U.S. Code

§ 2562. Presumption of validity; defenses