水稻莖稈特性與其對螟蟲之感受性關係研究

供試之臺中190號、臺農67號、臺中秈10號等3種水稻品種，二化螟蟲為害所引起之枯心率及白穗率均以臺中秈10號最高，被害率在12.9～16.05%，屬感蟲品種；而臺中190號較具抗性，被害率僅2.1及1.05%。於分蘗盛期調查稻株之莖寬與莖厚，以臺中秈10號之莖稈較寬，平均達11.05 mm，而臺中190號則僅為7.30 mm。莖厚也有類似情形，但差異較小。另以萬能物性試驗機測定莖稈強度，結果以臺中秈10號最弱，莖稈強度僅為1.87kg/cm^2，而臺中190號莖稈強度較高為3.72 kg/cm^2兩者相差一倍；不同施肥量對稻株之莖寬及莖稈強度有影響，少氮多磷鉀肥及增施矽肥可增加稻株之莖寬及莖稈強度，多氮少磷鉀肥區則反之。由於本試驗係表面施肥，故不同肥料量對螟蟲危害所引起之枯心率處理間差異不顯著。但對水稻生育中後期有影響，施用多氮少磷鉀肥區由於莖稈強度變軟，致使白穗率增加；而少氮多磷鉀及施用矽肥能使莖稈強度變硬，白穗率因之降低。

關鍵字

水稻；莖寬；莖厚；莖稈強度；枯心率；白穗率

並列摘要

Among the three rice varieties tested, the striped stem borer Chilo suppressalis Walker, caused the highest deadheart (12.9%) and whitehead (16.05%) damage in Taichung Sen 10 (a susceptible variety), and Taichung 190 was the most resistant to this borer with only 2.1% deadheart and 1.05% whitehead percentage. At maximum tillering, Taichung Sen 10 had the widest stem averaging 11.05 mm while the stem width of Taichung 190 averaged only 7.30 mm. The same difference, though slightly less significant, was observed in stem thickness. Measurement by the Rheometer revealed that the stem of Taichung Sen 10 was the weakest with a hardness of 1.87 kg/cm^2 while the stem hardness of Taichung 190, i.e., 3.72 kg/cm^2, was almost doubled. Fertilization rates significantly influenced the width and hardness of rice stem. Lower nitrogen, higher phosphorus and potassium and application of silica increased the width and hardness of the stem. Because foliar application of fertilizers was used in this experiment, no significant difference in deadheart damage was observed among treatments of various fertilizer rates. However, increased whitehead damage was observed in later stages of rice plants that received higher nitrogen and lower phosphorus and potassium. The stem of the rice plants receiving lower nitrogen and higher phosphorus and potassium was hardened and thus the whitehead percentage decreased.

並列關鍵字

rice ； stem width ； thickness ； hardness ； dead heart ； white head

國際替代計量

水稻莖稈特性與其對螟蟲之感受性關係研究

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