Problem to be solved: to provide a disease resistance enhancing agent effective for controlling disease of coffee stem.Problem to be solved: to control the disease of the coffee stem by applying the disease resistance enhancing agent of the coffee stem including lysine to the leaf of the coffee stem, etc.Diagram【課題】コーヒーノキの病害の防除に有効な病害抵抗性増強剤を提供する。【解決手段】リジンを含むコーヒーノキの病害抵抗性増強剤をコーヒーノキの葉等に施用することによって、コーヒーノキの病害を防除する。【選択図】図1