The present invention relates to a plant disease control agent containing a compound represented by the following formula (1) or salt thereof as an active ingredient (in the formula, R 1 and R 2 represents a hydrogen atom or methyl group but excepting cases where R 1 and R 2 are the same), a plant disease controlling method applying the plant disease control agent on plants suffering from diseases, and a novel compound represented by formula (1) or salt thereof.
