本研究主要目的在探討埋土深度對黃姨菜（Youngia japonica (L.) DC）、兔兒 菜（Ixeris chinensis (Thunb.) Nakai）及長柄菊（Tridax procumbens L.)種子萌芽與休眠之影響，將三種菊科植物種子埋入0〜5公分之土壤，試驗結束將未出土種子挖出進行生長箱發芽試驗，判斷未發芽種子為休眠或死亡，試驗結果如下：黃鵪菜、兔兒菜及長柄菊種子埋入 0 cm、0.2 cm、0.4 cm、0.6 cm、0.8 cm、1.0 cm、1.5 cm、 2.0 cm、2.5 cm、3.0 cm、3.5 cm、4.0 cm、4.5 cm、5.0 cm 公分深之土壤中，顯示以埋土 0〜0.4 cm幼苗出土率較高，出土率達56.0%以上，其中長柄菊埋土 0.4公分出土率尚達71.3 %，當埋土深度5 cm時，黃鵪菜及長柄菊種子無萌芽出土，兔兒草則有2.7 %之出土率，將三種菊科植物無出土種子進行休眠性檢定顯示有 65〜67%種子因深埋休眠而解除，而有16-35%則呈深度休眠或死亡種子。

The main purpose of this study was to investigate the effect of buried depth to seed germination and dormancy with Youngia japonica (L.) DC., Ixeris chinensis (Thunb.) Nakai and Tridax procumbens L.. Seeds of three Compositae plants were buried in 0~5 cm soil. At the end of the experiment, the unearthed seeds were excavated for growth chamber germination test to judge whether the ungerminated seeds were dormant or dead. The results were as follows: Youngia japonica (L.) DC., Ixeris chinensis (Thunb.) Nakai and Tridax procumbens L. were buried in the soil with 0 cm, 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm, 1.0 cm, 1.5 cm, 2.0 cm, 2.5 cm, 3.0 cm, 3.5 cm, 4.0 cm, 4.5 cm and 5.0 cm, which showed that seeds buried 0~0.4 cm had higher seedling emergence rate, and it was over 56.0%. The emergence rate of buried 0.4 cm with long-stemmed Tridax procumbens L. could reach 71.3 %. When buried depth was 5 cm, seeds of Youngia japonica (L.) DC. and Tridax procumbens L. could not germinate, but seeds of Ixeris chinensis (Thunb.) Nakai still had 2.7% emergence rate. Dormancy tests for three ungerminated seeds of Compositae performed that 65-67% of seeds dormancy released due to deep dormancy, while 16-35 % were deep dormant or dead seeds.