美国黑核桃嫁接育苗技术

黑核桃原产北美洲,属核桃科核桃属黑核桃种,为温带落叶树种,在美国广为栽培。尤以美国东部黑核桃为主是世界上公认的经济价值最高的材果兼优最佳硬阔材树种之一。国际市场对黑核桃木材的需求量与日俱增,引种栽培美国黑核桃成为世人公认的极具诱惑力的投资项目。该树种适应性强,耐寒程度高,抗寒类型可忍耐零下43℃的低温,耐干旱类型在年降水量3000mm左右的半干旱地区也能生长,     

美国东部黑核桃种子层积催芽的探讨

对美国东部黑核桃种子层积催芽前预处理方法和层积催芽时间进行了试验,认为层积催芽前冷水浸种5d,沙藏层积催芽150d,发芽最快。播种后60d调查,发芽率达75%。     

黑核桃良种苗木繁育技术

良种繁育是目前限制我国推广美国东部黑核桃的重要因素。通过试验研究，结合甘肃实际，总结出了黑核桃育苗地选择、种子调运采集、层积处理、催芽播种、苗木嫁接、苗期管理等良种苗繁育的主要技术。     

美国红栌容器育苗技术

章从容器的选择、营养土配制、整地、营养钵准备、播种和苗期管理等方面，详细介绍了美国红栌的容器育苗技术，在生产中有一定的指导意义。     

美国核桃、黑核桃引种试验*

自１９８４年开始，陆续引进了维纳、强特勒等１２个美国加州主栽核桃品种和黑核桃、魁核桃、小黑核桃、北加州黑核桃及其种间杂种（奇异核桃）等５个树种。１２个加州核桃品种的发芽期在北京比当地品种晚０～１８ｄ；其中维纳、强特勒、契可、爱米格、日地等５个品种具有早实、丰产的优良特性。种植在河南洛宁县土层深厚、土质中性的砂壤土上，８年生黑核桃树高达５ｍ，干径１４．６ｃｍ：在北京门头沟区干旱、瘠薄、碱性（ｐＨ８～８．５）的碳酸盐土壤上，６年生奇异核桃高达６．５ｍ，干径１８．５ｃｍ。     

黑核桃嫁接育苗技术

黑核桃以其木材质地优良，坚果可食，适生范围广，生长速度快以及对病虫害的抗性强等优良特性，于1991年被引种到新疆，经过数十年的栽培和研究，表明该树种在新疆具有广阔的发展前景。但由于黑核桃是从异国和内地引进，其种子、种苗价格偏高，而且用黑核桃实生苗栽植需6年结实，8年进入盛果期，见效期太长，生产单位不易接受，制约了黑核桃在新疆的发展。     

美国黑核桃优良无性系的引种

美国黑核桃优良无性系是20世纪90年代引进的优良核桃品种。行了物候期、形态特征、生长情况、开花结果观察、坚果性状分析和抗性分析研究,结果表明,美国黑核桃优良无性系适应该区域的气候条件,生长发育良好,是今后农用林发展的优势树种之一。     

火炬松容器育苗技术

本文对火炬松容器育苗中的浸种催芽、育苗沙床制作、营养杯的制作、放置营养杯的基床制作、芽苗移植和培育管理等技术措施进行了报道。     

美国黑核桃及其在内蒙古的引种驯化

内蒙古自然条件与美国黑核桃的适生条件有一定差异。1998年分别在内蒙古中部、东部、西部开展引种栽培试验，已于2001年开花结果。试验表明本区不是美国黑核桃的栽培禁区，只要栽培区域合理，选择适宜种源的实生优质种苗或适合本区生长的砧木嫁接苗，栽植前期管理保护措施得当，是可以成功的。通过试验初步认为，美国黑核桃能够在内蒙古南部有灌溉条件的地区栽培。     

Phosphorus requirements for containerized Pterocarpus indicus seedlings

Pterocarpus indicus Willd is a tropical woody legume that holds promise for plantation forestry. Two glasshouse experiments were undertaken on two soil types to determine the phosphorus (P) concentrati...     

木荷裸根苗和容器苗造林效果对比分析

采用一年生木荷容器苗和裸根苗在不同造林地类型上造林,比较造林效果。结果表明:木荷容器苗造林成活率和保存率在不同的造林地类型中均明显优于裸根苗。木荷容器苗造林树高生长和地径在不同的造林地类型中均明显优于裸根苗,并且差异显著。不同的造林地类型中,采伐迹地的成活率、保存率、树高生长量和地径生长量最好,其次为林冠下,再次为生物防火带。     

First year field growth of chemically root pruned containerized seedlings

Containers deform seedling root systems and have a potential to inhibit tree growth after outplanting. Ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa), western white pine (Pinus monticola Dougl. ex D. Don), and Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) were grown in containers coated with latex paint containing different concentrations of cupric carbonate and outplanted in a forest. Treatment effects on seedling growth and root morphology were determined after one growing season in the field. Seedling height was unrelated to treatment and stem diameter was not significantly affected (p0.05). New root growth in the upper portion of the root plug was significantly increased (p0.05). The optimal concentration of cupric carbonate for seedling root growth in the upper portion of the root plug was estimated by multiple regression.     

Transpiration of containerized Picea abies seedlings grown with different irrigation regimes

Norway spruce seedlings were grown in 50 ml pots, and irrigated when 30, 50, 70 and 90% of the liquid held at container capacity was left in the substrate. The total volume of nutrient solution added was smallest in the irrigation regime with the most frequent irrigation, and increased with decreased irrigation frequency. This was an effect of increased leaching with decreased irrigation frequency. Within each irrigation regime, the transpiration rate of the highest transpiring seedling was three times that of the lowest transpiring one. The transpiration rate was linearly related to shoot volume, independent of irrigation regime for approximately 50 days. Thereafter, the relationship became curvilinear and more affected by irrigation regime. The deviation from linearity was ascribed to an increased stomatal resistance when the growth substrate became drier. Towards the end of the experiment, the seedlings subjected to the most frequent irrigation transpired on a per seedling basis approximately four times more than seedlings subjected to the least frequent irrigation. Even on a shoot volume (or shoot dry weight) basis the transpiration was 2.5 times higher for seedlings with the most frequent irrigation compared to the ones in the least frequent irrigation. In conclusion, frequent irrigation with small volumes could be a way to reduce the risk for individual seedlings to experience the extreme conditions of drought and drowning, which could be one way to grow more uniform seedlings. Besides, the reduced drainage should reduce the pollution hazards, and more nursery resources could be converted to nursery products.     

江南油杉容器育苗基质筛选

用椰糠、泥炭土、塘泥、过磷酸钙和钙镁磷肥与南方普遍用作育苗基质的黄心土进行不同体积比或质量比混合作为育苗基质,开展江南油杉容器苗育苗基质试验,以期筛选出适合南方培育江南油杉的理想育苗基质.结果表明:育苗基质对江南油杉容器苗有较显著的影响,对苗木苗期的主要生长指标苗高、地径、根粗、保存率和生物量进行综合分析,筛选出较适合南方培育江南油杉容器苗的基质配方体积比为黄心土66.7％+椰糠33.3％,其次是黄心土50％+椰糠50％和黄心土80％+塘泥20％.     

Growth and nutrition of containerized Pinus Resinosa seedlings at varying moisture regimes

Containerized red pine (Pinus resinosa Ait.) seedlings were grown over a 16-week rotation at different irrigation treatments to assess moisture stress on plant growth and nutrition, and to evaluate container capacity as a guide for irrigation. Wet, moist and dry moisture regimes were induced by watering trees to the container capacity weight of the growing medium after declining to respective 92, 73 and 57% of this reference weight. The seedlings received the same amount of fertilizer over the growth period. Maximum shoot and root growth was attained under the wet moisture regime, but biomass was reduced 21 and 43% for the moist and dry regimes. Plant nutrient concentrations were not significantly affected by watering treatment, and vector diagnosis of dry matter production and element composition indicated that macronutrients were non-limiting. Seedling nutrient uptake however, was significantly diminished by moisture stress which was attributed to decreased root growth and lower mass flow and diffusion of nutrients when moisture availability was reduced in the peat rooting media. Container capacity was found to be a sensitive reference for judging the watering requirements of greenhouse-grown containerized seedlings. The method can be relatively easily applied on an operational basis.     

Effects of seed pre-soaking on the emergence and early growth of containerized Norway spruce seedlings

To study the effects of seed soaking on seedling emergence and development in Norway spruce [Picea abies (L.) Karst.] two commercial seed lots were soaked for 15 h in aerated water. After soaking, floating and sunken seeds were separated and analyzed prior to being sown in peat-filled containers. Seedling development was followed for one growing season. All sunken seeds were viable according to radiography whereas the floating seeds contained a considerable number of larvae filled and empty seeds. Mean time of emergence of the sunken seeds was approximately 1.5 days shorter than control (i.e. dry) seeds and floating seeds. Soaking had no effect on the time taken for most germinants to emerge in both seed lots, thus failing to synchronize seedling emergence. The later a seedling would emerge, the more likely it was for it to die during the growing season or to be culled at the end of the growing season. Soaking had an inconsistent effect on stem diameter at the end of the growing season and no effect on stem or root biomass. Seedling size uniformity was equal in all treatments. This study suggests that soaking and seed sorting does not guarantee a more uniform seedling crop, but this technique may be useful in upgrading poor quality seed lots of Norway spruce containing a high number of empty or larva infested seeds.     

长白山区核桃楸芽接技术研究

以核桃楸1 a生接穗为材料,研究不同芽接时间和方法对嫁接成活率和接穗生长量影响,结果表明:在不同嫁接时间对核桃楸接穗嫁接成活率影响试验中,6月5日嵌芽接成活率最高,为48.67%,其新梢平均长度和平均直径分别为17.02 cm和6.24 mm,显著高于方块芽接和"T"字形芽接;在不同嫁接方法对接穗成活率影响试验中,5、6月份和7、8月份嵌芽接平均成活率最高,分别为26.00%、31.90%,高于方块芽接和"T"字形芽接。嵌芽接值得推广,最适时间在6月初。     

The effect of low-temperature event on the survival and growth of Juglans mandshurica seedlings within forest gaps

In forest ecosystems, gap formation changes the allocation of abiotic resources and thus affects the survival and growth of understory plants.However, how tree seedling survival and growth respond to low-temperature events and the influencing mechanisms remain unclear.To clarify how low-temperature event limits the survival and growth of tree seedlings in the montane regions of eastern Liaoning Province, northeast China, we investigated temperature and light intensity within secondary forest gaps,and the survival and growth of Juglans mandshurica seedlings after a low-temperature event in the spring of2014.Damage to seedlings due to low temperature significantly varied in different aspects.Seedlings in gaps on southeast-facing slopes were the most seriously damaged,followed by those in gaps on northeast-facing slopes.In contrast, seedlings in west-facing gaps and in control plots without slope aspect were not damaged.The freezing injury index for seedlings was negatively correlated with minimum temperature(r =-0.608, P 0.01), but it was positively correlated with light intensity(r = 0.818,P 0.01).In addition, height and root collar diameter of damaged seedlings were significantly lower than those of the undamaged seedlings(P 0.01) during the early growing season(April–July), but no significant difference were observed during the late growing season(July–October)(P 0.05).The extent of seedling damage was directly related to slope aspect.Low temperature and high light intensity were found to be the dominant factors affecting extent of damage to seedlings on southeast-and northeast-facing slopes.