Growth Responses of Catalpa bungeito Nitrogen
Annotatsiya
Pot culture experiments were conducted to test the response of one year old Catalpa bungei C.A.Mey clone(I-4) to nitrogen application.Four tested nitrogen concentrations were 1 mmol/L,4 mmol/L,8 mmol/L and 16 mmol/L respectively.The experimental results with the increase of nitrogen application,the height growth showed the tendency of increase and then decrease,basal diameter,leaf number,leaf area and biomass increased with the increase of nitrogen application,whereas the root-top ratio decreased.Refers to the physical parameters,as the nitrogen applied increased,the contents of chlorophyll a,chlorophyll b and carotene increased,the contents of protein decreased on the contrary.Based on comprehensive analysis of height,basal diameter and biomass,it was concluded that the optimal nitrogen concentrations for one year old Catalpa bungei C.A.Mey clone(I-4) was 16 mmol/L.