插穗生根进程和粗细不同对落叶松扦插苗的影响

调查研究了日本落叶松１年生木质化枝春插生根进程和插穗直径粗细不同对扦插苗生根、生长的影响。在辽东气候条件下，萌发态木质化枝插后４９天开始生根，至２４天时生根率可达８６％以上。插穗直径≤２．５ｍｍ，生根率低。插穗直径增大，扦插苗生长和生根性状可得到明显改善，直径３．６～５．０ｍｍ的插穗生根率高达９４％以上。选用直径粗细适宜的插穗可大幅度提高日本落叶松硬枝扦插育苗效果，降低成本。     

插穗生根进程和粗细不同对落叶松扦插苗的影响

调查研究了日本落叶松１年生木质化枝春插生根进程和插穗直径粗细不同对扦插苗生根、生长的影响。在辽东气候条件下，萌发态木质化枝插后４９天开始生根，至２４天时生根率可达８６％以上。插穗直径≤２．５ｍｍ，生根率低。插穗直径增大，扦插苗生长和生根性状可得到明显改善，直径３．６￣５．０山的插穗生根率高达９４％以上。选用直径粗细适宜的插穗可大幅度提高日本落叶松硬枝扦插育苗效果，降低成本。     

日本落叶松不同无性系生根生长性状相关及苗期选择

研究了日本落叶松幼年采穗园不同母株不同年度插穗生根率的表现，不同无性系扦插苗当年生根、生长性状与２年生移植苗生长间的关系。并进行了苗期速生无性系选择。     

落叶松杂种大规模繁殖配套技术研究

研究了日本落叶松×长白落叶松不同杂交组合的授粉可配性、可育性 ,杂种苗生长、杂种采穗园母株插穗产量和全光雾插条件下不同组合、单株插穗经不同浓度激素处理的生根以及大田生根插穗移植成活、生长情况。日本落叶松×长白落叶松种间易于杂交 ,不同组合间授粉可配性和杂种苗生长差异十分明显。尽管组合间插穗生根存在着明显差异 ,但幼年母株插穗一般生根容易 ,不经任何激素处理生根率也能达到 90 %以上。采穗园 2 .5～ 3.5年生杂种母株 ,平均可繁殖 13～ 2 7株·株 -1 、 级 2年生扦插苗。基于目前的研究结果组装各环节最佳方案 ,用人工控制授粉的方法配制优良组合 (一般、特殊配合力高 )的杂种种子 ,播种育苗后建采穗园进行扦插繁殖 ,即能在短期内大量增殖这些珍稀的遗传改良杂种     

插穗长度与GGR6处理对乌柳扦插苗生长的影响

为了研究插穗长度和植物生长调节剂GGR6处理乌柳扦插苗生长的影响,本文通过设置,不同长度插穗,不同GGR6浓度处理,比较分析乌柳扦插苗的生根及苗期生长特点。结果表明:在一定范围内,插穗长度大于10cm,对高生长、分枝数和成活率均有显著的促进作用,小于10cm,成活率、高生长量显著降低;100ppmGGR6是适合乌柳扦插苗处理的最佳浓度。     

日本落叶松整形修剪对母株生长、产穗量、插穗生根和扦插苗生长的影响

研究了高，中柱式，矮台式整形修剪方法对不同年龄（2-10a生）日本落叶松采穗母株生长，产穗量，插穗生根（无激素处理）及2a生扦插苗生长的影响。结果表明：日本落叶松实生幼年母株每年进行整形修剪，虽然不能完全抑制老龄化对母株插穗生根的影响。但有助于幼化复壮母株组织。未加整形修剪的10a（实际为9.5a)生树形母株的插穗生根率只有24.8%。而同龄经不同剪控措施处理的母株插穗生根率可达55.2%-81.1%(平均64.9%)，均极显著地大于对照。整形修剪方式不同，对母株生长（地径），产穗量和插穗生根率等的影响不同。高，中柱式母株由于修剪相对较轻，生长量大，产穗量高，3.5a,5.5a和8.5a生3个年龄阶段平均产穗量分别为110.5,237.0,173.0穗和85.9,150.7,98.0穗，均显著或极显著地大于矮台式母株（相应地分别为54.3,61.4,43.0穗）。高，中柱式母株虽在生长和产穗量方面具有明显的优势，但母株5.5a生以后插穗生根率呈下降趋势，至9.5a生时骤降至58.3%,55.3%。受连年重剪的影响。矮台式母株生长量小，产穗量小，死亡率高，但延缓老龄化和幼化效果好，7.5a以后插穗生根率才开始下降，与高，中柱式相比，母株插穗生根率开始下降的年龄推迟约2a，并且生根率下降的幅度小，至9.5a生时仍可达81.1%。母株幼年阶段（2.5a生）整形方式对2a生扦插苗的生长影响不明显，但当母株达到一定年龄阶段后（7.5a生）矮台式母株2a生扦插苗高度（44.8cm)显著大于高柱式母株（33.4cm)。为充分发挥采穗母株生产潜力和剪控的幼化效果，日本落叶松幼年实生母株在建圃最初几年应采用高柱式修剪，一定年龄阶段后（8a生）采用再截干幼化处理的方法降低母株高度，以改善插穗生根效果和延长采穗圃使用年限。     

厚皮毛竹生长特性研究

厚皮毛竹生长特性研究＠郭起荣＠杜天真＠张露＠胡宜柏＠冷德家＠韦旭￥江西农业大学林学院￥江西宜丰林业局厚皮毛竹，生长特性厚皮毛竹生长特性研究＊郭起荣杜天真张露胡宜柏冷德家韦旭（江西农业大学林学院南昌３３００４５）（江西宜丰林业局关键词：厚皮毛竹生长特性厚皮毛...     

不同苗龄落叶松造林效果分析

本文对长白落叶松进行了同年育苗、不同苗龄的造林对比试验。经五年观察,结果表明,用一年生苗造林比二年生苗造林生长得快,用一年生苗造林每亩可增加育苗收入1847元。     

日本落叶松整形修剪对插穗产量及生根率的影响

研究了日本落叶松采穗园母株高、中柱式，矮台式等３种整形修剪方式，产穗母枝留茬长度，采条时期等对母株生长、新枝萌发生长、穗条产量及插穗生根效果的影响。高、中柱式母株平均产条量显著大于矮台式。与２年生时相比，３年生母株插穗产量增加一倍以上，平均插穗产量分别达到２８４．６，２０９．８，１３５．５根／株。不同整形方式母株３－３．５年生木质化、半木质化插穗生根率无显著差异。用０．００５％的ＩＢＡ溶液处理后生     

日本落叶松林分密度与胸径、树高生长关系的探讨

日本落叶松林分密度与胸径、树高生长关系的探讨苑辉（辽宁省林科院１１００３２）目前，日本落叶松（ＬａｒｉｘｋａｅｍＰｆｅｒｉ）人工林在辽宁省已大面积郁闭成林，中、幼林占的比例较大，调节和控制林分的密度，可以在林木各生长阶段改变干材的质量和村积生长量，并...     

Improving the evaluation of multiple-dowel-type connection strength

Our study focuses on predicting the ultimate short-term load carrying capacity of timber-to-timber connections with dowel-type fasteners. The wide range of possible configurations in practice makes the resolution of these values by tests unrealistic. Moreover, different current regulations do not consider some specific failure mechanisms. In many countries, the reduction of resistance involved by this phenomenon is taken into account by considering an effective number of dowels (n_ef) smaller than the actual number of dowels (n) in the connection. However, these different regulations disagree on the values of n_ef and on other points (spacing, partial coefficient of security, formulas). These discrepancies in design rules invite the fundamental research on this topic and, therefore, new methods are sought in order to estimate the load carrying capacities of the connections. In the light of these, our approach consists of predicting the load carrying capacity with the neural network numerical tool. The results obtained by this analysis tool are satisfactory, although the model remains complex. Subsequently, we focus on the simplification of this numerical model with classical regression techniques in order to implement it in a design code.     

Insecticidal activity of certain medicinal plants

The methanol extracts of eight species of medicinal plants were tested for insecticidal activity in third instar larvae of Egyptian cottonworm (Spodoptera littoralis). All extracts showed a certain degree of larval toxicity. The extracts of Ocimum basilicum, Origanum majorana and Salvia officinalis appeared to be highly toxic. The extracts significantly affected the growth indexes [relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD)].     

Rehabilitation of diseased cacao fields in Peru through shade regulation and timing of biocontrol measures

The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased (moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to 25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol can realise their production potential.' This revised version was published online in June 2006 with corrections to the Cover Date.     

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.     

Constituents of aromatic plants: carvacrol

Carvacrol is a component of numerous aromatic plants. Up to now, no toxicological data were available. Carvacrol show a weak activity in the mutagenicity studies. Moreover, in the metabolism study, carvacrol has shown to be excreted with urine after 24 h in large quantities or unchanged or as glucoronide and sulphate conjugates. The available data do not allow the assessment of the NOEL. Further toxicological studies are needed.     

Populations of adult fungus gnats and shore flies in British Columbia container nurseries as related to nursery environment,and incidence of fungi on the insects

Adult fungus gnat and shore fly populations were monitored in four container nurseries near Victoria, British Columbia. In general, populations of both insects were larger in summer than in winter. Also, both insects were more abundant in the nursery with a plastic-covered, soil floor, which favored moisture accumulation and build up of algae, liverworts and mosses, than in nurseries with other types of floors such as cement. Results of fungus isolations revealed that gnats and flies both harbor the seedling pathogens Botrytis cinerea and species of Fusarium and Phoma, plus several non-pathogenic fungi. The results are discussed in relation to nursery sanitation practices, their effects on gnat and fly populations, and some possible roles of these insects in seedling disease epidemiology.     

Trees and shrubs as sources of fodder in Australia

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline.     

崖柏属植物的核型分析

[目的]为了从细胞学角度探讨崖柏属植物分类与进化问题,[方法]采用根尖压片法对崖柏属5种植物进行核型研究。[结果]表明:崖柏和日本香柏的核型公式为2n=2x=22=18m(2SAT)+4sm,朝鲜崖柏、北美乔柏和北美香柏的核型公式为2n=2x=22=20m(2SAT)+2sm,5种植物的核型均属于1A类型。[结论]该属在柏科中可能处于比较进步的进化地位;通过进化趋势图分析发现,崖柏在该属中分化最晚,而朝鲜崖柏则较原始。     

Antimicrobial activity of some medicinal plants from India

The results of a preliminary antimicrobial screening of the methanol extracts of Zingiber officinale, Asteracantha longifolia, Citrus acida, Salacia microsperma and Tinospora cordifolia are reported.     

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.