遮光对红豆杉生长规律及枝叶产量的影响

Effect of Shading on Yield of Branches and Leaves and Growth Law of Taxus spp.

为探寻遮光度对红豆杉生长规律及枝叶产量的影响,进而确定有利于红豆杉生长和枝叶产量提升的适宜遮光度和采收季节,对红豆杉的苗高、地径生长指标进行持续性测定和调查分析。结果表明:遮光能有效延长红豆杉植株的生长周期,但不同光照条件下红豆杉苗高、地径的生长节律大致相同,均表现为3—4月生长缓慢,4—8月进入第1个高速生长期,8—10月生长减缓,10—12月进入第2个高速生长期,12月至翌年2月,生长再次减缓甚至停滞。遮光度65%较遮光度50%、遮光度35%和全光条件,最有利于红豆杉生长和枝叶产量的提升,平均苗高为113.20 cm,平均地径为24.57 mm,平均枝叶产量371.97 g·株^-1。种植红豆杉紫杉醇原料林,宜选择2年生红豆杉一级壮苗,在遮光度65%的条件下种植,枝叶采收则应在当年的12月至翌年2月进行。

In order to explore the effect of shading on the growth law and the yield of branches and leaves,and then determine the appropriate shading degree and harvest season that are conducive to the growth of Taxus spp.and the increase of the yield of branches and leaves.The seedling height&ground diameter growth indicators of Taxus spp.were continuously measured&investigated,and the branches&leaves were harvested after the investigation was completed.Result shows that shading can effectively prolong the growth cycle of Taxus spp.plants,but the growth rhythms of seedling height&ground diameter for Taxus spp.are approximately the same under different light conditions,and both show slow growth from March to April,and enter the first from April to August.During the high-speed growth period,growth slowed from August to October,and the second high-speed growth period entered from October to December.From December to February of the following year,growth slowed down or even stopped again.Compared with the shading degree of 50%,shading degree of 35%&full-light conditions,the shading degree of 65%is most conducive to the growth of Taxus spp.and the increase of leaf yield.Under this shading degree,the average seedling height of Taxus spp.is 113.20 cm.The average ground diameter is 24.57 mm,and the average branches&leaves yield per yew reach 371.97 g.Therefore,when planting a yew paclitaxel raw material forest,a two-year-old Taxus spp.first-class seedling should be selected and planted under the condition of 65%shading.Branch and leaf harvesting should be conducted from December of that year to February of the following year.