Abstract:The effects of 4 color shading-nets (red:shading rate 45.0%,blue:shading rate 51.1%,grey:shading rate 47.2%,black:shading rate 47.3%) on plant growth and photosynthetic characteristics of flowering Chinese cabbage (Brassica campestris L.ssp.chinensis (L.) var.utilis Tsen et Lee) were studied.The results showed that red-net covering increased plant height,stem diameter,total plant fresh mass and leaf area of flowering Chinese cabbage significantly,while blue,grey and black net covering decreased plant growth characteristics comparing with the control (no shading).The 4 shading nets covering significantly reduced plant specific leaf mass,while the contents of chlorophyll a,b,total chlorophyll and carotene were increased with the tendency black net>red net>grey net>blue net>control.The ratio of chlorophyll a/b was decreased by shading treatments compared with the control.In the light density range of 0-2 000 μmol/(m2·s),net photosynthetic rate (Pn) of flowering Chinese cabbage leaf increased steadily with the increase of light density,and the Pn value among treatments showed control≈red net>blue net>grey net>black net.Apparent quantum yield (AQY) of flowering Chinese cabbage in red-net shading treatment increased by 1.1%,compared with the control,but decreased by 30.3%,44.0%and 54.2% in blue,grey and black net shading treatments,respectively.Red-net shading could promote plant growth of flowering Chinese cabbage significantly by improving its photosynthetic performance,indicating that it was suitable for popularization and application.