One of the most important amendments of the UPOV Convention when it was revised in 1991 was the introduction of the concept of essential derivation.
Article 14 of the 1991 Act of the UPOV Convention, which defines the scope of the breeder’s right, provides in paragraph (5)(a)(i) that the scope of the breeder’s right apply in relation to varieties which are essentially derived from the protected variety, where the protected variety is not itself an essentially derived variety.
In paragraph (5)(b) of Article 14 there is a definition of an essentially derived variety from an initial variety: