红麻旺长期的冠层光能利用率以叶面积系数3.5最高,超过4则形成大量消费叶。小于2则冠层透光率过大,光能利用不足。旺长期后,由于红麻植株冠层顶部变尖,株型向有利于吸收更多光能的方向改变,叶面积系数在5以上能获得更大的光合产量。红麻的生长速率在旺长初至旺长中期上升最快,旺长中期与开花前都维持较高水平,但旺长后期(7/下—8/上),叶面积系数达最高4左右,个体与群体生长明显不协调,这以后中下部大量叶片转化为消费叶,从而导致8月下旬出现生长速率低谷。净同化率则在苗期、旺长中期及纤维积累盛期均较大,而旺长中期之前,由于新叶发生速度快,叶面积系数迅速上升及旺长后期叶片衰老,叶面积比下降幅度大,相对生长速率降低,这两个时期的净同化率相对较低。 The long-term energy utilization rate of kenaf with the highest leaf area coefficient of 3.5, more than 4, the formation of a large number of consumer leaves. Less than 2 canopy light transmittance is too large, insufficient use of light energy. After a long period of growth, the kenaf plant had a sharp change in the top of the canopy, and the plant type changed in a direction that favored absorption of more light energy. Larger leaf photosynthetic rate above 5 yielded greater photosynthetic production. The growth rate of kenaf rose rapidly from the first to the mid-Mongolian wang, and remained at a high level in the mid to mid-pollen and before flowering. However, the leaf area index reached a maximum of about 4 in the late Mongolian (7 / -8 / up) , Individuals and groups obviously incoherent growth, after which a large number of leaf into consumer leaves, resulting in the late August growth rate trough. Net assimilation rate was higher at the seedling stage, mid-wang and mid-accumulation period, but before the mid-long period, due to the occurrence of new leaves, the rapid increase of leaf area index and the leaf senescence in late growth stage, Large, relative growth rate decreased, the net assimilation rate of these two periods is relatively low.