1Institute of Agricultural Quality Standards and Testing Technology Research，Hubei Academy of Agricultural Sciences，Laboratory of Quality & Safety Risk Assessment for Agro-products（Wuhan），Ministry of Agriculture and Rural Affairs，Hubei Key Laboratory of Nutritional Quality and Safety of Agro products，Wuhan 430064，Hubei，China；2Tuanfeng Agriculture and Rural Affairs Bureau，Huanggang 438000，Hubei，China
Abstract：Chlormequat chloride（CCC），as a plant growth regulator has been widely used in vegetable production．In order to investigate the using effect and safety of CCC on acquatic vegetable Artemisia selengensis Turcz.，this experiment adopted field trial method，set 4 levels of CCC concentration（0，150，300，450 mg ·L-1）and studied the effects of CCC on dissipation rule of Artemisia selengensis Turcz.，and its yield，quality and nitrogen utilization characters．The results showed that the degradation rule of CCC on Artemisia selengensis Turcz.was in accordance with the first-order kinetics equation．Its half-life period in stem was only 6.9-9.1 days．The degradation rate was significantly greater than leaves．After foliar spraying in the seedling period，all harvested stems were safe inspection．But in leaves，CCC residues all exceed the standard，except those treated with low concentration（150 mg · L-1）．As the spraying CCC concentration increased，the content of chlorophll in leaves and soluble sugar content in stems were gradually increased，and the dwarf degree of plant was intensified．But，its yield，apparent using efficiency of nitrogen，nitrogen partial productivity，nitrogen agronomic efficiency all showed a downtrend．Low CCC concentration（150 mg · L-1）treatment had insignificant effect on dwarf of Artemisia selengensis Turcz. plant．The single plant stem weight and single plant leaf weight were 57.5 g and 45.0 g，respectively．Compaired with the treatment without spraying CCC，the yield of Artemisia selengensis Turcz. was increased by 13.5% and nitrogen agronomic efficiency was increased by 49.9%．To sum up，low CCC concentration（150 mg · L-1）could be applied safely during the planting process of Artemisia selengensis Turcz．
