利用触破式微粒胶囊剂防治栗山天牛成虫试验初报

通过利用触破式微粒胶囊剂进行栗山天牛成虫的野外防治试验，发现触破式微粒胶囊剂对栗山天牛成虫有较好的防治效果，并且残较期长达40d左右。通过本试验还筛选出林间最佳防治用药剂量和施药期，为今后采用科学的防治方法提供了科学依据。     

触破式微胶囊剂防治天牛成虫试验研究

通过林间应用触破式微胶囊剂 (Aprionagermari)防治杨树桑天牛、柳树光肩星天牛成虫试验 ,结果表明该药剂不仅对两种天牛致死快、防治效果显著 ,且药效持续时间长达 5 0天。     

触破式微胶囊剂防治黄斑星天牛试验

触破式微胶囊剂是防治杨树蛀干害虫的新型药剂。通过防治黄斑星天牛Anoplophora nobilis Ganglbauer成虫试验 ,施药 40天后罩网平均防效达 91 .6 % ,地面防效调查平均单株成虫死亡数为 5 6 0头 ,防治效果显著 ,在杨树天牛防治工作中具有较好的推广应用前景     

触破式微胶囊剂防治杨树天牛试验

触破式微胶囊剂是防治大型害虫的新型药剂,通过防治杨树蛀干天牛成虫田间试验、罩网防治试验,施药52天后具有较强的触杀作用和很长的持效期,伐倒木罩网不同施药浓度38天后的平均死亡率95.53%。防治效果显著,用浓度以0.33%为宜。     

触破式微胶囊剂防治黄斑星天牛试验

触破式微胶囊剂是防治杨树蛀干害虫的新型药剂。通过防治黄斑星天牛Ａｎｏｐｌｏｐｈｏｒａ ｎｏｂｉｌｉｓ Ｇａｎｇｌｂａｕｅｒ成虫试验，施药４０天后罩网平均防效达９１．６％，地面防效调查平均单株成虫死亡数为５６０头，防治效果显著，在杨树天牛防治工作中具有较好的推广应用前景。     

林间药剂喷雾防治新疆光肩星天牛的药效试验

通过选择48%乐斯本、5%锐劲特、2.5%溴氰菊酯、8%触破式微胶囊剂、2%噻虫啉微胶囊悬浮剂等5种高效低毒农药对光肩星天牛(Anoplophora glabripennis Motschulsky)进行喷雾防治试验,结果表明:防治效果较理想的为8%触破式微胶囊剂、2%噻虫啉微胶囊悬浮剂和5%锐劲特3种药剂,防效分别达到80.7%、78.1%和76.3%。     

直升机喷洒微囊剂防治松褐天牛的药效试验

以诱捕到的松褐天牛成虫总数来测定8%氯氰菊酯触破式微囊悬浮剂(绿雷二代)和3%噻虫啉缓释型微囊悬浮剂防治对松褐天牛的飞机防治效果。结果表明:8%氯氰菊酯触破式微囊悬浮剂和3%噻虫啉缓释型微囊悬浮剂都对松褐天牛有较强的毒力,但8%氯氰菊酯触破式微囊悬浮剂药效持效期更长,可高达1个月以上;在后续的田间试验防治松褐天牛试验中,两种药剂设置用药量分别是6.67 mL/hm2和13.34 mL/hm2,和空白对照3个处理,分别设3个重复。两种药剂结果对比发现,8%氯氰菊酯触破式微囊悬浮剂比3%噻虫啉缓释型微囊悬浮剂表现出更好的速效性、持效性和综合防效的稳定性;8%氯氰菊酯触破式微囊悬浮剂对松褐天牛的虫口减退率始终保持在90%-98%之间,3%噻虫啉缓释型微囊悬浮剂对松褐天牛成虫虫口减退率仅在药后6～22 d期间防效达到90%以上。     

触破式微胶囊剂防治光肩星天牛成虫的初步应用

通过林间用触破式微胶囊剂防治杨树光肩星天牛试验 ,发现该胶囊剂对光肩星天牛有较强的杀灭效果 ,而且持效期长达 42d以上。并提出了内蒙古自治区防治光肩星天牛的林间最佳防治用药浓度、施药方法和施药期。     

触破式微胶囊与缓释性微胶囊制剂有何区别

正触破式微胶囊是利用昆虫触破胶囊时短时间内释放出高效原药杀死昆虫,缓释性微胶囊是通过缓慢释放有效充分杀死昆虫并延长持效期。缓释性微胶囊在用于天牛类大型害虫时存在一个问题,就是由于天牛类害虫一般个体大,耐药力强,仅靠少量恒定释放剂量不足以将天牛成虫杀死,而且还有可能诱导其抗药性,而触破式微胶囊克服了缓释性微胶囊短时间内释放剂量     

应用绿色威雷防治绒毛白蜡云斑天牛试验研究

云斑天牛(Batocera horsfieldi)是黄河三角洲广泛栽植的绒毛白蜡(Fraxinus velutina)最重要的蛀干害虫之一,其成虫补充营养期是防治的关键时期。应用绿色威雷(8%触破式微胶囊水悬剂)0.25%、0.33%、0.5%浓度的药液对绒毛白蜡云斑天牛成虫进行喷雾防治试验,以罩网法和地面法调查平均防治效果分别为90.7%和86.2%,防治效果非常显著,且特效期长达50d。     

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.     

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.     

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。     

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.