(10(4):47-52)EFFECT OF CHEMICAL ELEMNTS ON THE GROWTH OF CROP PATHOGENS 1. Effect of Cd、Co、Cu、Zn and Mn on the fungi of rice blast and shesth spot diseases

著者等為明瞭各種化學元素，對植物病原菌發育之影響而舉辦本試驗，並希望本資料能供抗病原理研究之參考；另一方面祈能成為新殺菌藥劑發現上之基木資料。又本試臉採用Cd、Co、Cu、Zn、Mn 等五種金屬之硫酸鹽、硝酸鹽、氯化物等三種鹽類共十五種化合物。並以稻熱病菌及稻紋枯病菌為試驗對象，將其主要結果事項列舉如下： (1）本試驗採用之五種元素中以Cd對稻熱病菌及稻紋枯病菌之發育抑制力最為顯著。 (2）Co及 Zn兩元素在10-3Mol 時，亦有抑制稻熱病菌及稱紋枯病菌之發育。 (3）在本試驗之三種銅鹽類中，除CuCl2有抑制稻熱病菌及稻紋枯病菌之發育外，其他鹽類均無顯著之抑制作用。 (4）據本試驗之觀察 Mn 稍有促進發育之傾向。 (5）三種鹽類之中以氯化物之毒性為最強。 (6）對稻熱病菌發育抑制力之順位是 Cd > Co > Cu > Zn > Mn 而對稻紋枯病菌卻是 Cd > Co > Zn > Cu > Mn 之順位。 In order to clarify the influence of chemical elements (Cd、Co、Cu、Zn and Mn) upon the growth of Pirioularia orvzae Cay. and Corticium Sasakii (Shirai) Matsumoto et Yamamoto, this experiment was made. The results will be summarized as follows: 1. It was found that Cd is one of the most toxic element to the growth of both fungi deseribed above. 2. When treated with concentration 10-3Mol., Co and Zn were toxic to the growth of fungi, but no effect was found when treated with less than 10-3Mo1. 3. It was found the copper chloride showed significant effect on the growth of fungi but not for other copper compounds under the concentration of this experiment. 4. Mn was found to promote the growth of fungi under condition of the present experiment. 5. Chloride salt was found to be the most toxic to the fungi within three kinds of salt used. 6. The order of inhibition of chemical elements on the growth of Pirioularia oryzae was found to be Cd>Co>Cu>Zn>Mn, and that of Cortium Sasakii was Cd> Co>Zn>Cu>Mn