A chemical composition for reducing stress on a plant comprising: at least one substance (A) selected from the group consisting of compounds represented by Formula (I) and the like and a salt thereof and a substance (B) which affects a physiological function of the plant [in Formula (I), R 1 to R 4 each independently represents a hydrogen atom, -SO 3 H, -PO 3 H 2 , glycosyl group or -COR 11 . R 11 represents an unsubstituted or substituted C1 to C30 alkyl group or an unsubstituted or substituted C2 to C30 alkenyl group.].