PROBLEM TO BE SOLVED: To provide a technique against diseases that cause lesions or symptom expressions in potato tubers, the technique enabling to diagnose the growth state of a crop with respect to an influence from a pathogenic microorganism without digging out the tubers as well as irrespective of the presence or absence of lesion or symptom expression of tuber disease.SOLUTION: The method for diagnosing the growth state of potato (Solanum tuberosum) crop with respect to influence from a pathogenic microorganism of tuber disease comprises the steps of: providing as an index value the content of organic acid in an aboveground part of a potato crop or a level based on the content of the organic acid and, with respect to the aforementioned index value, making a comparison between an index value from an aboveground part of potato provided as a diagnosis target and an index value from an aboveground part of a crop in a healthy field to determine the presence or absence of or the degree of substantial difference between the indexes.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2017,JPO&INPIT【課題】ジャガイモ塊茎に病斑又は病徴が発現する病害に関して、塊茎を掘り起こすことなく且つ塊茎病害の病斑又は病徴の発現の有無に関わらずに、当該病害原因微生物からの影響に関する作物体の生育状態を診断可能とする技術を提供する。【解決手段】塊茎病害原因微生物からの影響に関するジャガイモ(Solanum tuberosum)作物体の生育状態を診断する方法であって、ジャガイモ作物体の地上部における有機酸含量又は当該有機酸含量に基づく値、を指標値とする工程、及び、前記指標値について、診断対象である作物体地上部からの指標値と健全圃場での作物体地上部からの指標値とを比較して、指標値間の実質的な差異の有無又は差異の度合いを判定する工程、を含む。【選択図】図4
