红麻冠层发育 光能截获及群体生长的关系分析

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。

Analysis on the relationship between the canopy developing and photo-energy utilizing as well as population growing in kenaf

In the fast growing stage of kenaf, the proportion of photo-energy utilizing was the best when canopy was developing at 3.5 of leaf area coefficient. However, when the leaf area coefficint was more than 4, a number of consuming leaves were formed, but when less than 2, photo-energy were insufficiently utilized. After the fast growing stage of kenaf, photo-energy was best utilized at the leaf area coefficient of 5 since, in this stage, the canopy was developing into the formes of best photo-energy adopted.However, the growig rate was greatly increasing at the stage of between early to middle fast growing and maintaining at high level from middle fast growing to pre-flowering stage. The growing rate in late Augest was lower as many consuming leaves were emerging. There were high net assimination at the stage of seedling, mid-fast growing and high fiber assimination. But, the net assimination rate was comparatively low at both of early and fast growing period.