The Effect of Trace Elements on Disease Resistance in Crops (1) The Effect of Manganese on Blast Disease Resistance of Rice.

Abstract

If the amount of Mn applied exceeded a certain limit (about 200 ppm), the growth of rice seedlings were markedly reduced, and at the same time, the development of blast lesion after inoculation was inhibited. However, a small amount of Mn promoted both. By chemical analysis of the plant, it was found that the N content was reduced with the increase of Mn application. 本試驗係水耕液巾加注不同濃度之Mn，觀察對於稻熱病之發生與稻苗生長之影響而舉辦者。茲將其結果摘要如下： 1.加注Mn區之草高均比標準區（無加注區）為不良，如加注高濃度（200 ppm,500ppm)時其差異更顯著。葉長如加注Mn 0.5~20ppm者與標準區之差異不顯著，但加注50ppm 風上時有類著之差異。 2.根長及葉寬除高濃度（200 ppm, 500 ppm）有顯著之差異外，其他處理區均與標準區略為相同。 3.對稻熱病發生之影響，如Mn濃度低（50 ppm以下），則無顯著之影響，但濃度高（200 ppm似上）則顯著減少稻熱病之發生，並同時呈現相當之藥害。 4.處理後之稻苗將分析其莖蘖囊內之N,Mn含有量，則Mn之含有量添加區均較無添加區為高，N之含有量除0.5 ppm區外均比無加注區較低。 5.稻苗莖葉的煎汁調製培地，培養稻熱病菌時，加注Mn 0.5, 1及2 ppm 區之發育較無添加區稍為優，其他比2 ppm較高濃度區在培地上均會抑制稻熱病菌之發育。