The present invention enables providing a method for cultivating a crop plant into which has been introduced either one or both of (1) DNA comprising a nucleotide sequence encoding the amino acid sequence of a cytochrome P450 that shows saflufenacil metabolizing activity and (2) DNA comprising a nucleotide sequence encoding the amino acid sequence of a protein that shows protoporphyrinogen IX oxidase activity, wherein said method comprises applying a weed control agent that contains saflufenacil as an active ingredient to an area where said crop plant is cultivated； among others.
