ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of S-3307 spraying time and density on photosynthetic characteristic of Ligusticum chuanxiong.</p><p><b>METHOD</b>The photosynthetic characteristic of L. chuanxiong under different S-3307 spraying time and density was studied by plot cultivation experiment.</p><p><b>RESULT</b>The content of chlorophyll a and chlorophyll b in leaf increased when the spraying density was 20, 40, 80 mg x L(-1), while the net photosynthetic rate was the maximum. When the spraying density was 160 mg x L(-1), the content of chlorophyll a and chlorophyll as well as net photosynthetic rate were not increased.</p><p><b>CONCLUSION</b>S-3307 spraying can raise the photosynthetic capacity of L. chuanxiong and promote the form of assimilation products.</p>