经营措施对日本落叶松插穗质量及生根率的影响

Effect of fertilization, prunning and density on cutting quality and rooting ability of stem cuttings of Larix kaempferi (Lamb.) Carr.

依据扦插生根率的差异 ,探讨了经营措施对日本落叶松插穗适插性能的影响 .分析表明 ,一定量的施肥能够显著改善插穗的生根能力 ,与对照相比可提高生根率 14%～ 37% .生根期间 ,施肥处理的插穗体内N ,P含量较未施肥者有更大的内迁移率 ,推测施肥促进了插穗体内的养分代谢活动 .强度修剪和密度控制不一定增加插穗的总产量 ,但可显著地提高植株中、下层有效穗条 (长度 >15cm ,基径≥ 0 3cm)的数量 .枝条发育在生长季前期主要受修剪的影响 ,后期主要受栽植密度的影响 .通过修剪控制采穗母株的树体高度 ,确定合理的栽植密度是 1 5h(东西向 )× (1 0～ 1 2h) (南北向 )的间距 .

Significant differences in rooting ability of \%Larix kaempferi\%(Lamb.) Carr. stem cuttings were observed as a result of cultural conditions varied with stock plants. Data showed that the application of a specific amount of urea to ortets increased the rooting percentages of cuttings by 14%～37% compared with control. In contrast, the nitrogen and phosphorus concentrations in the former cuttings decrease more than that in the latter during root formation. This changed process suggested the endogenous nutrient metablism stimulated by exogenous fertilizer. The cutting production from heavy hedged donor stocks was similar to that of unhedged ones, but those truncated and topped into the middle\|sized cylindricality type give more expected cuttings both in quantity and in quality (length>15 cm, basal diameter≥0.3 cm), and special improvements were found at the middle and lower layers of the crown. For larch significant effect of prunning on new shoots development at the level of \%P\%=0.01 occurred only in the first half of growth season, in the second half an orchard density became the dominant factor influencing good cutting forms which were relative to rooting potentials. As there was a strong correlation between crown layers of plants and the accumulated irradiance on them, a reasonable 1.5 h×1.0～1.2 h space among seedlings in a hedged orchard is recommended according to the variance of shade length and bearing of ortets with motive orbit of the sun, when H represents the height of individuals.