When sprayed glyphosate twice (between 30 days), the inhibition of shikimate content in root tissues was remarkably accelerated by the low glyphosate dosage in comparison with that of the high dosage.

• 二次施用草甘膦（间隔30天）的结果表明，低剂量处理对抑制空心莲子草根组织莽草酸含量的积累更明显。