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在室内培养条件下,采用菌丝生长速率法测定了6种杀菌剂对桑膝节霉的抑制效果。结果显示,6种杀菌剂对桑树轮纹病病原菌桑膝节霉的菌丝生长均有不同程度的抑制作用,其中50%多菌灵、75%百菌清、10%苯醚甲环唑、250 g/L丙环唑、450 g/L咪酰胺和70%甲基硫菌灵的EC50分别为2.45 mg/L、2.51 mg/L、1.68 mg/L、1.31 mg/L、0.46 mg/L和7.99 mg/L。测试药剂中,供试桑树轮纹病菌对450 g/L咪酰胺最为敏感,250 g/L丙环唑次之。450 g/L咪酰胺和250 g/L丙环唑皆可作为防治桑树轮纹病的最佳药剂,用于田间试验。 相似文献
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为筛选出高效防治葡萄灰霉病的杀菌剂,采用菌落生长量法,室内测定8种市场主流杀菌剂抑制武威灰葡萄霉孢菌株的毒力。结果表明:80%腐霉利、50%多菌灵、10%叶菌唑为高毒力药剂,半效浓度≤100 mg/L;250 g/L苯醚甲环唑、25%吡唑醚菌酯、25%氰烯菌酯为中毒力药剂,半效浓度290~380 mg/L;720 g/L百菌清、0.3%四霉素为低毒药剂,半效浓度>700 mg/L。0.3%四霉素、10%叶菌唑随浓度增加其抑菌效应的增长较快,80%腐霉利增长较慢,其余5种供试药剂的增长则相对平缓。综合分析,筛选出50%多菌灵、10%叶菌唑、四霉素,供武威市防治葡萄灰霉病中交替使用。 相似文献
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指出了侧柏叶枯病是侧柏的一种重要叶部病害。为了筛选出对侧柏叶枯病防治效果较好的化学药剂,选择了50%多菌灵、50%百菌清、40%灭病威、50%苯醚·甲硫、50%叶枯唑5种化学药剂对侧柏叶枯病进行了防治试验。结果显示:50%苯醚·甲硫1000倍液防治效果最好,防效达到90%;其次是50%叶枯唑1000倍液防治效果为87%;50%灭病威1000倍液防治效果最差,只有63%。从药剂防治效果来看,防效从高到低依次为50%苯醚·甲硫50%叶枯唑50%多菌灵40%灭病威50%百菌清。并且随着药剂稀释倍数的加大,防治效果呈递减状态。最佳防治时期为6月中旬。 相似文献
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为了有效防治银杏根腐病,以取自石家庄槐安西路、唐山建设路、保定长城北大街、河北农业大学校内的银杏根系为试材,采用组织分离法对其病健组织的病原菌进行分离及形态鉴定;在室内条件下,采用菌丝生长速率法研究比较5种杀菌剂对病原菌的毒力作用;并将筛选出来的药剂做田间防效试验.结果表明:该试验共获得2个具有致病性的菌株SJZ-4、SJZ-5,这2个菌株均为尖孢镰刀菌(Fusarium oxysporum);室内筛选出了3种抑菌效果较好的药剂,即枯草芽孢杆菌、30%苯醚甲环唑、80%多菌灵;稀释300倍的枯草芽孢杆菌田间防治效果最好,可使62.5%的银杏夏季不焦叶或者仅轻微焦叶,严重焦叶(焦叶量>70%)的发生程度仅为6.25%. 相似文献
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7种杀菌剂对杨树烂皮病、溃疡病病菌的室内毒力测定 总被引:1,自引:0,他引:1
室内测定了7种杀菌剂对杨树烂皮病病原菌金黄壳囊孢菌Cytospora chrysosperma (Pers.)Fr.、溃疡病病原菌Dothiorella gregaria Sacc.的毒力.72 h含药平板对抑制金黄壳囊孢菌的菌丝生长毒力最强的有10%苯醚甲环唑水分散剂、250 g/L嘧菌酯悬浮剂,EC50值依次为0.0006,0.020 2μg/mL;其次为70%甲基托布津可湿性粉剂,EC50为0.195 8μg/mL;最弱的是树乐粉剂,EC50为319.658 0μg/mL.48 h对杨树溃疡病病原菌的毒力最强的有250 g/L嘧菌酯悬浮剂、10%苯醚甲环唑水分散剂,EC50依次为0.072 2,0.090 4μg/mL;其次为70%甲基托布津和50%多菌灵可湿性粉剂,EC50依次为2.5603,19.0454 μg/mL;树乐最弱,EC50为366.415 7μg/mL.同一药剂对杨树烂皮病菌的毒力强于溃疡病菌. 相似文献
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桉树小新壳梭孢梢枯病菌室内药剂毒力测定 总被引:1,自引:0,他引:1
在室内培养条件下,采用生长速率法测定了10种常用杀菌剂对桉树小新壳梭孢枝枯病菌Neofusicoccum parvum (Penny Cook & Samuels)的抑制效果,结果表明:25%苯醚甲环唑和25%丙环唑对N.parvum抑制效果最好,EC50值分别是0.0312和0.0330 mg/L;18.7%丙环·嘧菌酯、25%咪鲜胺、50%甲基硫菌灵、50%异菌脲、50%多菌灵、40%腈菌唑和75%百菌清抑菌效果次之,EC50值分别为0.0499,0.0681,0.1462,0.1672,0.2720,0.3454和4.6199 mg/L;25%嘧菌酯抑菌效果最差,EC50值是16.1451 mg/L. 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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《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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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
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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(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