不同品种枸杞产量的对比分析

为了选择出适宜甘肃省中部黄河上游灌区栽培的优良枸杞品种,从宁夏、内蒙古引进了10个枸杞品种并开展栽培对比试验,对各品种2龄幼树全年7次采摘的干果产量进行了方差和产量累进曲线分析。结果表明,品种间产量差异显著;0901、宁杞3号、宁杞4号、宁杞7号、宁杞5号5个品种产量均较对照宁杞1号有所增加,从产量指标上判断,可作为适宜栽培品种。10个品种夏果累进增速均较秋果快;秋果产量是影响总产量排名的主要因素;适宜栽培品种中,宁杞3号秋果产量增速最快,应重视果园秋季管理,以进一步提高产量;宁杞5号秋果产量增速最慢,宁杞7号增速较慢,应主抓夏果的生产;0901、宁杞4号、宁杞1号全年产量增速较平稳,应同时重视夏果、秋果的生产。     

长林3号等油茶品种引种栽培试验初报

从亚林所引种长林3号、4号等5个油茶新品种,栽培6年后,单株产量2.51～4.87kg,比对照提高58.8%～208.2%,且品种间差异显著;冠幅产量1.71%～2.48kg/m2,比对照提高14.0%～65.3%;666.7m2平均产油17.56～34.88kg,比对照提高了114.9%～326.9%。引种的品种与原产地相比,各项经济指标变化不大。长林3号、4号等油茶品种适应性强、丰产稳产、产油高、抗性强,是适合湖北省推广的优良品种。     

天麻原种室内袋式河沙高产栽培技术研究

采用自行研究的室内袋式河沙栽培法与对照湖北山区常规土壤固定菌床窖式栽培法,对天麻原种进行了栽培经济性状的比较。室内河沙栽培的5个月红天麻原种产量达3.64 kg/m2,生产1 kg天麻原种菌材用量仅为1.65 kg,投入产出比为1∶10.2;而对照原种产量0.98 kg/m2,生产1 kg天麻原种菌材用量15.31 kg,投入产出比为1∶4.0。两者相比,提高产量271%,节约菌材9.28倍,投入产出比提高2.55倍。室内袋式河沙栽培的红天麻、乌天麻、乌×红杂交天麻和绿天麻原种与对照相比,室内袋式河沙栽培法生产的原种依品种不同,平均单位粒重提高0.71~4.4倍,最大单粒重提高3.2~4.5倍,可缩短不同品种原种栽培期4~12个月。     

部分野生与栽培牡丹种质资源亲缘关系的RAPD研究

利用RAPD技术对芍药属牡丹组的 11个野生牡丹类群和 12个栽培牡丹品种间的亲缘关系进行了研究。筛选出的 17个单引物和 1个组合引物共扩增出 191条谱带 ,其中 15 3条表现多态性 (占 80 1% ) ,揭示了牡丹组植物丰富的遗传多样性。对扩增结果进行UPGMA聚类分析表明 :革质花盘亚组的野生类群与栽培品种聚为一类 ,革质花盘亚组各野生种与栽培品种间的亲缘关系都比较近。 5个野生种与受试牡丹品种间的平均遗传距离值为 0 4 8～ 0 5 7,与栽培牡丹间亲缘关系从近到远依次为 :杨山牡丹、四川牡丹、卵叶牡丹、紫斑牡丹和矮牡丹。另外 ,本次RAPD试验扩增出的 2 5个特异标记可用于牡丹组内种间、品种间的分类与鉴定。     

板栗良种铁粒头,石丰,九家种引种试验

经过在湖南省的小面积引种试验,筛选出表现优良的铁粒头、石丰、九家种3个板栗品种。以湖南省主要农家品种——它栗作对照,进一步进行品比试验,获得了与小面积引种栽培试验基本一致的结果;与此同时,还进行了多点试验,参试品种的丰产性能在不同试验点表现基本一致;历时14年的引种试验证明,这3个品种在湖南省自然条件下生长、结实良好,引种获得了成功。     

枇杷疏花疏果技术及对产量品质影响研究

通过对各参试品种在湘南低山丘陵区红壤土、石灰土、钙质土立地条件下枇杷优质丰产高效栽培技术研究及相关资料的系统分析,提出了枇杷疏花疏果技术要点。并以红壤土上10~14年生太城四号枇杷为材料,系统研究了疏花疏果对枇杷果实产量及品质的影响。结果表明:太城四号枇杷疏花疏果后以每穗留果3~5个为最佳,疏果后平均单果重、单株产量及收益分别比对照提高117%、32%、163%。同时可提高果实的可食率、可溶性固形物含量、含糖量,降低含酸量,有效改善果实品质、口感风味、色泽,大大缩短果实采摘期。     

武汉地区早钟6号枇杷引种栽培试验初报

枇杷是原产于我国的主要水果之一,多年来在武汉地区只有零星的栽培.枇杷品种多,丰产性好,但适生性的差异显著.为了引入适合武汉地区栽培的枇杷品种,掌握其引种栽培特性和技术措施,于2006年春季引种3年生早钟6号枇杷190株,按株行距为4 m×2 m的密度栽植,建立了引种实验园0.15 hm<'2>,次年挂果,产量为3 00...     

黑龙江省保护地厚皮甜瓜引种比较试验

筛选出适合黑龙江省栽培的优良厚皮甜瓜品种。以厚皮甜瓜品种伊丽莎白为对照品种,引进了6个厚皮甜瓜品种进行栽培适应性试验,经过3年试验,调查分析不同品种的生物学特性、植物学特性、产量和品质等性状。试验表明:特异性厚皮甜瓜品种风味4号在试验点的总体表现优良,它生育期适中、比较早熟;生长势强,坐瓜较早;产量高、品质优良、风味独特、抗病性好;综合性状优于对照品种伊丽莎白和其他品种,比较适合在黑龙江地区棚室栽培。     

天麻一代和多代栽培对比及添加配料试验

天麻无性1代和多代种应用5种栽培方法进行产量比较,天麻无性1代种根据不同栽培方法其产量为3.90～10.35kg/m2,比无性多代分别提高15.77%～51.16%,平均提高27.66%;5种栽培方法以茵材伴栽与培育栽培法最优,平均天麻栽培产量达9.65 ks/m2;3种添加配料以H淀粉增产效果最好,比对照分别增产8.66～16.52%,平均增产12.34%.上述项目内容对比试验,效果显著,对天麻生产具有指导意义和应用推广价值.     

丽江市油橄榄丰产栽培试验研究

在丽江市玉龙县大具乡进行油橄榄丰产栽培试验研究。文中阐述油橄榄的栽植、土壤管理、水肥管理、整形修剪、病虫害防治等技术方法。试验结果表明，佛奥、豆果、皮瓜尔3个参试品种的扦插苗（2a生）第三年开始结果，参试品种的单株产量、公顷产量与对照组相比均有较大提高，达到了丰产的效果。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.