Effects of Rare Earth La on Some Physiological Indices of Rape and Its Critical Concentration

Effects of lanthanum on the growth and some other physiological indices of rape (Brassica juncea),such as biomass,chlorophyll content,nitrate reductase,root activity,were studied in a solution culture experiment.The results showed that the biomass,chlorophyll content,nitrate reductase activity and root activity increased when 0 03～3 mg/kg La ³⁺ was sprayed or added into the culture solution,and decreased,but POD activity,when more than 30 mg/kg La ³⁺ was added.The critical concentration of lanthanum to rape was suggested to be 30 mg/kg.