Lysenkoism was a political campaign led by Soviet biologist Trofim Lysenko against genetics and science-based agriculture in the mid-20th century, rejecting natural selection in favour of a form of Lamarckism, as well as expanding upon the techniques of vernalization and grafting.

Trofim Denisovich Lysenko was a Soviet agronomist and pseudoscientist. He was a strong proponent of Lamarckism, and rejected Mendelian genetics in favour of his own idiosyncratic, pseudoscientific ideas later termed Lysenkoism.