Formula (A) as for the phosphate, it is possible in regard to the auxiliary substance in order this invention, the polar solvent, and formula (A) included the phosphate (the later mentioned sort), to reinforce the activity of the shooting harmful biological agent, to exist as a acidity, and/or as a salt as for the polar solvent, it is possible, possesses the 60 super flash point to mix with the water at optional ratio. In environment or the crop around those where this invention, in the shooting harmful biological agent and the agricultural chemical composition which includes the auxiliary substance, in manufacturing method of the auxiliary substance to which makes with the polar solvent and formula (A) the phosphate contact, in use of the auxiliary substance in order to reinforce the activity of the shooting harmful biological agent, and the plant pathogenic bacteria and/or the desirable vegetation and/or controls the attack of the desirable insect or tick, and/or furthermore regards the method of adjusting the growth of the plant, the said composition, in the respective pest, should protect from the respective pest, the soil and/or the desirable plant and/Or the crop and/or it makes that it operates the environment around those possible.< Selective figure >It is not本発明は、極性溶媒、及び式(A)のリン酸エステル(後述の通り)を含んだ、殺有害生物剤の活性を増強するための補助剤に関し、式(A)のリン酸エステルは、遊離酸として、及び/又は塩として存在することが可能であり、極性溶媒は、任意の比率で水と混和することができ、60℃超の引火点を有する。本発明は、殺有害生物剤及び補助剤を含んだ農薬組成物に、極性溶媒と式(A)のリン酸エステルとを接触させる補助剤の調製方法に、殺有害生物剤の活性を増強するための補助剤の使用に、並びに植物病原菌及び/又は望ましくない植生及び/又は望ましくない昆虫若しくはダニの攻撃を抑制し、及び/又は植物の成長を調節する方法にさらに関し、該組成物が、それぞれの有害生物に、それぞれの有害生物から保護されるべきそれらの周囲環境又は作物に、土壌及び/又は望ましくない植物及び/又は作物及び/又はそれらの周囲環境に作用することを可能にする。【選択図】なし