PROBLEM TO BE SOLVED: To provide a bactericide for agricultural and horticultural uses, containing cupric hydroxide and reinforced with controlling effects against plant pests, and a method for controlling the plant pests by using the same.SOLUTION: An agrochemical hydratable composition obtained by blending cupric hydroxide is characterized in that among 5 strong lines (until fifth diffraction peak by an order of having strong diffraction intensity) in the powder X ray diffraction (CuKα: 1.5412 Å) of the composition, equal to or more than one peak disappearing in the powder X ray diffraction of a dried material of diluted liquid dried on leaf surfaces after spraying the diluted liquid obtained by dispersing the composition in water on an objective plant, or the diffraction intensities of ≥2 diffraction peaks decrease to ≤3/4.COPYRIGHT: (C)2014,JPO&INPIT【課題】水酸化第二銅を含有し、植物病害に対する防除効果が増強された農園芸用殺菌剤及び該剤を用いて植物病害を防除する方法を提供する。【解決手段】水酸化第二銅を配合してなる農薬水和性組成物であって、該組成物の粉末X線回折(CuKα:1.5412Å)における5強線(回折強度の強い順に5番目までの回折ピーク)のうち、該組成物を水に分散させた希釈液を対象植物に散布後、葉面で乾燥した希釈液乾燥物の粉末X線回折では1以上の回折ピークが消失する、または2以上の回折ピークの回折強度が3/4以下に低下することにより特徴付けられる農園芸用水和性殺菌剤により上記課題を解決する。【選択図】なし