日本植物病理学会报-J-Stage.PDFVIP

日本 植 物 病 理 學 會 報 第 一 巻　第 六 號 大 豆 の紫斑 粒 に關す る研 究 松 本 巍 友 安 亮 一 STUDIES ON PURPLE SPECK OF SOYBEAN SEED by Takashi Matsumoto and Ryoichi Tomoyasu The occurrence of purple speck on soybean seed has long been noticed by many growersand investigators,but until recentlyno considerableattention was given as a disease, as it does not cause any serious damage on growing plants. According to the recent informations given by the Akita and Hokkaido Agricult ural Experiment Stations, however, a rather considerable economic loss due to the purple speck has been noticed by impairing the commercial standing of the bean to no small degree. Concerning the cause of the disease Suzuki (21) noticed that the trouble might be attributed to the mechanical stress exerted by the pod in consequence of unequal rate of growth between pod and seed; thus climatic conditions being considered as a chief cause of the disease. R. Kikuchi working with the same disease expressed his opinion in his private letter sent to the senior author on November 21, 1922 that the cause of the disease might be due to a fungus parasite which seemed to belong to the genus Cercospora. Subsequently Kung (23) confirmed the responsibility of a fungus parasite, but nothing has been touched upon the subject to determine whether the pathogen is the same with 2 友安、松本-大豆の紫斑粒に關す る研究 that observed by Kikuchi or not. Acoording to the more recent paper (23) published by the Shigaken Agricultural Experiment Station, however, the disease might b