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以竹类热处理的副产物竹焦油为原料,柑桔为供试作物,选用60%竹焦油钠盐水剂、75%竹焦油钾盐水剂和50%竹焦油乳油,以20%三氯杀螨醇乳油为对照药剂,对柑桔全爪螨进行田间药效试验。结果表明:60%竹焦油钠盐水剂、75%竹焦油钾盐水剂对甘桔全爪螨的校正防效与对照药剂20%三氯杀螨醇乳油差异不显著,且不同浓度之间无显著性差异。50%竹焦油乳油药后3-7天防效均高于对照药剂,田间试验表明50%竹焦油乳油是一种良好的天然杀螨剂,对柑桔全爪螨具有较强的防治作用。 相似文献
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5种植物源农药对黄脊竹蝗毒力及毒饵的制备与防治效果 总被引：5，自引：5，他引：0
为揭示5种植物源农药对黄脊竹蝗毒力强度，探寻制备诱杀黄脊竹蝗成虫新型毒饵的方法，采用碳酸铵、碳酸氢铵和氯化铵与5种植物源农药混合制备毒饵，并进行诱杀黄脊竹蝗成虫试验。结果表明：5种农药对黄脊竹蝗均有良好的致死作用，1%苦参·藜芦碱可溶液、1.2%烟碱·苦参碱乳油、0.5%藜芦碱可溶液、1.5%苦参碱可溶液和4%鱼藤酮乳油对黄脊竹蝗跳蝻和成虫的LC50依次为1.527、0.856、1.931、0.927、1.602 mg/L和1.767、0.957、2.176、1.126、1.825 mg/L；碳酸铵、碳酸氢铵和氯化铵水溶液可代替人尿作为引诱剂，其最佳浓度配比为70、80和90 g/L，5种植物源农药可代替化学药剂作为胃毒剂，胃毒剂与引诱剂的体积比：1.2%烟碱·苦参碱乳油和1.5%苦参碱可溶液均为1∶30，1%苦参·藜芦碱可溶液和4%鱼藤酮乳油均为1∶20，0.5%藜芦碱可溶液为1∶15。本研究提出的毒饵制备方法，可广泛用于大量诱杀黄脊竹蝗成虫，可为黄脊竹蝗的无公害防治乃至综合防治提供借鉴。 相似文献
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6种植物源农药对竹斑蛾幼虫的毒力及应用分析 总被引：1，自引：1，他引：0
为筛选有效控制竹斑蛾（Artona funeralis）幼虫的植物源农药,选用6种植物源农药开展室内毒力测定和林间防治效果分析。结果表明：6种植物源农药对竹斑蛾幼虫均有良好的致死作用。参试的植物源农药以1.2%烟碱·苦参碱乳油和1.5%苦参碱可溶液的毒力较强,0.4%蛇床子素乳油的毒力较弱;4%鱼藤酮乳油、1.2%烟碱·苦参碱乳油、0.4%蛇床子素乳油、1%苦皮藤素可溶液、碧绿1%苦参碱和1.5%苦参碱可溶液对竹斑蛾幼虫的LC50分别为0.826 mg/L、0.596 mg/L、1.016 mg/L、0.962 mg/L、0.811 mg/L和0.612 mg/L;林间施药4 d后,6种植物源农药的防治效果均超过90%;最佳田间施药浓度为：1.5%苦参碱可溶液和1.2%烟碱·苦参碱乳油均为1 500倍液,碧绿1%苦参碱和4%鱼藤酮乳油均为1 200倍液,0.4%蛇床子素乳油和1%苦皮藤素可溶液均为1 000倍液。参试的植物源农药对竹斑蛾幼虫的防治效果良好,可用于生产上防治竹斑蛾幼虫。 相似文献
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用50%竹焦油乳油分别对水稻纹枯病、稻曲病和黄瓜白粉病进行田间药效试验表明,其防治效果为水稻纹枯病59.1%~74.1%,且使用浓度250、500倍的情况下,对其平均防效与5%井冈霉素WC200倍相当;防治稻曲病效果为56.3%~73.6%,250倍明显高于20%三唑酮EC1000的防治效果;防治黄瓜白粉病效果为63.6%~78.0%,在使用浓度250、500倍的情况下,对其平均防效优于0.3%多抗霉素AS 800倍处理。50%竹焦油用量以500倍为宜。因此,竹焦油EC对3种病原菌均有较好的防治效果是一种高防效低残留安全性好的新型广谱性杀菌剂。 相似文献
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5种生物农药喷雾防治竹镂舟蛾幼虫效果评价 总被引：1，自引：1，他引：0
为揭示无公害防控竹镂舟蛾的关键技术,在福建政和县选择竹镂舟蛾为害的毛竹林设立试验研究区,选用1.5%苦参碱可溶液、3%高渗苯氧威乳油、25%阿维·灭幼脲悬浮剂、1.2%烟碱·苦参碱乳油和1.8%阿维菌素乳油等5种生物农药,应用无人机喷雾技术,开展防治竹镂舟蛾幼虫用药的最佳使用剂量筛选试验,并检测竹林土壤和竹笋中的农药残留。结果显示：药后5 d,5种农药均有2个浓度水平对竹镂舟蛾幼虫的校正死亡率达86%以上;农药的最佳浓度水平(用纯净水以体积比稀释的倍数)是：1.5%苦参碱和1.2%烟碱·苦参碱均为1 500倍液,3%高渗苯氧威为2 500倍液,25%阿维·灭幼脲为1 000 倍液,1.8%阿维菌素为800倍液。在竹笋和土壤中均未检出所施的农药成分。研究结果表明,试验的5种农药对竹镂舟蛾幼虫致死作用强、防效好,且不会产生农药残留,竹林喷施这5种农药,可大幅降低竹镂舟蛾幼虫的虫口数量,达到无公害防控竹镂舟蛾成灾的目的。 相似文献
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2种植物源农药烟雾对黄脊竹蝗的防治效果 总被引：2，自引：2，他引：0
为试验喷烟施放1.2%烟碱·苦参碱乳油和1.3%苦参碱可溶液对黄脊竹蝗的防治效果，确定其最佳应用浓度及药剂用量，在福建省三明市梅列区的灰竹林中开展喷烟防治试验。试验结果表明：施药后4 d，1.2%烟碱·苦参碱乳油和1.3%苦参碱可溶液2种农药对黄脊竹蝗成虫的防治效果均超过86.7%，最佳应用浓度配比均为农药与烟雾剂的容积比为1：7，药剂最佳用量分别为900 mL/hm2和1 050 mL/hm2。喷烟施放2种植物源农药对黄脊竹蝗成虫的致死作用强、防治效果佳，可在生产中用于防治工作。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
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. 相似文献
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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. 相似文献
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Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
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. 相似文献
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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。 相似文献
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Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
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. 相似文献
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《Wood material science & engineering》2013,8(2):76-84
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. 相似文献