PROBLEM TO BE SOLVED: To provide a bactericide composition for agricultural and horticultural use that contains a copper 8-quinolinonate agent with an enhanced controlling effect.SOLUTION: A bactericide composition for agricultural and horticultural use contains both copper 8-quinolinonate and dipotassium hydrogen phosphate.SELECTED DRAWING: None【課題】8-ヒドロキシキノリン銅剤の防除効果を増強させた農園芸用殺菌剤組成物を提供する。【解決手段】8-ヒドロキシキノリン銅と、リン酸水素2カリウムとを併用する。【選択図】なし