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对云杉新播和换床苗的不同施氮量、不同施氮次数、不同施氮时间等因素与苗木生长的相关关系进行了研究,结果表明:尿素最佳施肥量新播苗为10 g/m^2,换床苗为24 g/m^2;以2次施氮为好;新播苗2次施氮最佳时期:第1次为6月上旬,第2次为6月下旬;换床苗2次最佳施氮时期:第1次为5月中下旬,第2次为6月上旬至下旬。 相似文献
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<正>樟子松换床苗是指2a樟子松留床苗,高不足10cm,苗木纤细,木质化不好又具有培育价值的苗。苗木换床的好处在于降低新育苗的成本,提高优质的成苗产量,而且能起到切根的作用。 相似文献
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对丰产素在落叶松育苗上的应用进行介绍。通过对落叶松换床苗木浸根和落叶松换床苗木及新播苗木叶面喷施,对试验结果进行分析论证,综合评定丰产素在落叶松育苗上的增产效果。 相似文献
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多效唑、矮壮素对绿篱植物大叶黄杨的矮化效果研究 总被引:3,自引:1,他引:2
通过不同浓度的多效唑、矮壮素在绿篱植物大叶黄杨上的矮化效果试验及效果比较,探索化学修剪中的最佳药剂品种、最佳浓度、药害浓度,为绿篱植物的化学修剪提供参考。试验表明:多效唑比矮壮素矮化效果明显,且观赏性、安全性更好;多效唑在单一大叶黄杨绿篱的化学修剪中,适宜浓度范围是0.2‰~1.0‰,最佳浓度1.0‰,用药量500ml/m2,喷施3次,药害浓度为1.5‰;矮壮素的适宜浓度范围是1‰~2.4‰,最佳浓度2.4‰,用药量500ml/m2,喷施3次,药害浓度为3.6‰。 相似文献
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为解决大枣根蘖苗造林成活率低的难题 ,应用ABT生根粉 3号对枣树根蘖苗木进行浸根处理试验 ,结果表明 :应用质量分数为 1.0× 10 -3 的ABT生根粉浸根 ,苗木生根率、成活率、生长高度均高于对照苗木。平均生根数 16条 ,平均根长 2 5 .5cm ,分别为清水对照处理的 2 .2 9倍和 3.6 4倍 相似文献
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文章研究了晚秋沙棘嫩枝扦插苗根系的生长发育规律和形态变化,把根系的生长发育科学的划分为三个阶段。把幼根期确立为床苗最佳移植期,可显著提高晚秋沙棘扦插苗成活率。 相似文献
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【目的】为充分利用杂种优势,从白蜡杂交种中筛选出优良耐盐株系,【方法】采用盆栽试验方法,研究了不同浓度NaCl(0‰、2‰、4‰、6‰)胁迫对绒毛白蜡新品种‘青碧’不同半同胞家系子代苗的生长量、膜透性、丙二醛(MDA)含量、脯氨酸(Pro)含量、超氧化物歧化酶(SOD)以及叶绿素含量的影响,并结合隶属函数法综合评价4个白蜡杂交组合一年生苗的抗盐能力强弱。【结果】1)盐胁迫抑制了各半同胞家系子代的生长量,随着NaCl浓度的提高,各组杂交苗的苗高增长量、地径增长量均呈下降趋势,其中68号、70号杂交苗的下降幅度相对较小;盐胁迫对不同亲本的杂交子代生理指标的影响不一致:2)膜透性、MDA含量、脯氨酸含量均呈现出逐渐升高的趋势,68号杂交苗的膜透性及MDA含量受影响最小,70号杂交苗的脯氨酸含量增长幅度最大;各组杂交苗的SOD活性变化规律不一致,70号杂交苗的SOD活性增长幅度最大,其次为68号;3)叶绿素含量变化也无一致规律,在6‰浓度下,68号杂交苗的叶绿素含量最高。【结论】利用隶属函数法对4组杂交子代苗的耐盐性进行综合评价,各杂交材料耐盐性强弱顺序为:68号> 70号> 69号>‘青碧’半同胞。研究结果可为选育白蜡优良耐盐新品种提供理论依据和种质材料。 相似文献
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杉木营养平衡与苗木干物质的分配关系 总被引:6,自引:3,他引:6
详细研究了不同营养 (N、P、NP)条件下杉木苗木干物质在根冠的分配规律 ,结果表明 ,不同的营养条件可导致苗木光合产物在根冠发生明显再分配 ,苗木的营养状态和根冠干物质分配的关系规律可应用异速生长模型y =axk 来描述和刻划。基于营养与光合产物在根冠的再分配规律及异速生长模型参数k值对营养胁迫反应的敏感性变化规律 ,提出了新的营养平衡理论和营养诊断方法 (称之为苗木群体营养诊断法 )。营养诊断法则为 :(1)在某一营养条件下 ,如果苗木异速生长模型参数k <1时 ,表明根系相对生长速率高于冠层相对生长速率 ,苗木处于营养亏缺状态 ;(2 )当k >1时 ,表明苗木冠层相对生长速率高于根系 ,苗木处于营养过剩状态 ,一般在自然条件下 ,k >1是不会出现的 ;(3)当k =1时 ,表明根系和冠层相对生长速率相等 ,苗木处于营养平衡状态。根据新的营养诊断方法 ,制定了杉木叶片和土壤营养诊断标准 ,并通过大量的杉木幼、中、近熟林施肥试验结果验证了营养平衡理论的正确性。 相似文献
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Fine roots are important in root absorption of nutrient and water, and in root turnover. Accurate definition of fine roots is a prerequisite to improved estimation of the physiological and ecological functions of forest ecosystems. Root development and physiological functions are reflections of root anatomical structure. In this study, the anatomical structures of different root orders were analyzed by examining paraffin sections of one-year old Fraxinus mandshurica seedlings. One-year-old F. mandshurica seedlings had over five root orders. The root anatomical structures of all orders showed more differences. First and second order roots consisted of four sections: the epidermis, cortex, pericycle, and vascular bundles. Fourth and fifth order roots were mainly composed of the skin and peripheral vascular bundles (including the xylem and phloem). Third order roots had root epidermal and cortical structures, but the quantity and integrity of the cortical cells were inferior to those of the first and second order roots, and superior to those of the fourth and fifth order roots. All the first and second order roots and some third order roots with discontinuous cork layer (< 0.4 mm in diameter), but not the fourth and fifth order roots, were the fine roots of one-year old F. mandshurica seedlings. Although they had similar diameters, different portions of root systems had different anatomical structures and therefore, vary in capacity to absorb water and nutrients. Fine roots were accurately defined by root diameter, branch orders, and anatomical structural features of one-year old F. mandshurica seedlings. 相似文献
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Joanna Mucha Andrzej M. Jagodziński Bartosz Bułaj Piotr Łakomy Adrian M. Talaśka Jacek Oleksyn Marcin Zadworny 《Annals of Forest Science》2018,75(1):22
Key message
Quercus robur seedling mass was affected more by planting density than by taproot pruning. Root pruning enhanced stem biomass at the expense of roots in later growth stages. Alteration of biomass allocation due to nursery practices may result in greater susceptibility to injury and death of the seedlings under unfavorable environmental conditions.Context
Plants adjust their growth and modulate the resource allocation in response to applied treatments and environmental conditions.Aims
The aim was to examine how taproot pruning in seedlings grown at different densities affected long-term growth of Quercus robur.Methods
Seedlings, sown as acorns at two planting densities, with or without pruned roots were harvested in the second, fourth, and fifth years of growth. The effect of root pruning on biomass allocation was determined by measuring leaf, stem, and root mass fractions; carbohydrate concentrations in the roots; and C/N ratios. Specific leaf area and root length were also determined to assess morphological adaptations to growth conditions.Results
Total seedling mass was affected more by planting density than by taproot pruning. After 4 years of growth, root mass fractions were lower and stem mass fractions were greater in seedlings planted at a higher density. Five-year old root-pruned seedlings also had a lower root mass fraction and higher stem mass fractions than unpruned seedlings. Specific root length was not affected by root pruning or planting density.Conclusion
Decrease of relative root biomass with simultaneous increase of stem biomass may be a long-term consequence of taproot pruning of Q. robur, and the effects may manifest years after the seedling stage.20.
孟加拉东南部土壤中的砷含量很高,不仅威胁人的健康,而且对土壤也有破坏作用。云南石梓(Gmelina arborea)在孟加拉是个快速生长的树种,也是含砷土壤中的潜力树种。研究评价了含砷试验土中丛枝菌根真菌对云南石梓(Gmelina arborea)生长的影响。播种前,四种不同浓度的砷(10mg·kg-1、25mg·kg-1、50mg·kg-1和100mg·kg-1)被加入到试验土中。记录生长参数,如,植物的根、苗鲜重、干重、冠幅径、根长和苗高、根瘤菌和孢子菌群落。菌根植株较非菌根植株生长好。与其它含砷量高的土壤中植株的生长情况相比,在含砷量为10-mg·kg-1的土壤中,菌根植株和菌根生长效果最佳,菌根植株生物量最高。随着砷浓度的增加,种苗生长,根瘤菌和孢子菌群落均明显降低p0.05)。与非菌根植株比较,菌根植株高生长增加了40%,生物量增加了2.4倍。研究表明,根瘤菌接种可以减少有害土壤中的云南石梓(Gmelina arborea)的初生长的影响。 相似文献