淡色缘脊叶蝉生物学特性及防治

淡色缘脊叶蝉是为害喜树的一种重要害虫,在四川1年发生3代,以成、若虫危害树叶,10月下旬成虫将卵产于枝干皮层内,以卵越冬。通过试验筛选出40%乐果乳油2000倍液,50%杀螟松乳油1500倍液;40%氧化乐果乳油、50%甲胺磷乳油15倍液;92%磷胺乳油、40%氧化乐果乳油2倍液;200ppm花虫敌和2.5%甲基1605粉剂,于8月中下旬采取喷雾、涂干、注干、喷粉的方式防治,杀虫效果达90%以上,保叶效果达80%以上。     

树干注射法防治灰同缘小叶蝉试验

灰同缘小叶蝉(Coloana cinerea Dworakowska)是秋枫的重要害虫.用16％虫线清乳油、20％叶蝉散乳油、30％氯胺磷乳油、40％乐果乳油和3％吡虫啉微乳剂原药对灰同缘小叶蝉进行树干注射防治试验,结果表明:40％乐果乳油施药后7d和14 d,防治效果为98.78％和97.88％,防效良好;30％氯胺...     

灰同缘小叶蝉危害特征与识别

灰同缘小叶蝉是危害秋枫的主要害虫之一。以成虫和若虫密集在叶背吸食汁液,使叶片提前脱落,严重影响秋枫的正常生长和观赏价值。珠三角地区灰同缘小叶蝉发生普遍,株被害率和叶片受害率达100%。秋枫叶片受害后叶片正面出现黄褐色斑点,严重时全叶枯黄而提前脱落。灰同缘小叶蝉雌雄成虫主要鉴别特征是雌虫腹部末端为圆形,中间为黑色产卵器。雄虫腹部末端有两个发达的尾节侧瓣,周围排列一圈白色刚毛。自然种群性别比例为1∶1.47(♀:♂)。     

板栗栗红蚧防治试验初报

选用 40 %速扑杀乳油、2 5 %敌杀死乳油、40 %氧化乐果乳油、5 0 %甲胺磷乳油、5 0 %敌敌畏乳油、2 0 %三唑磷乳油和 90 %晶体敌百虫等 7种农药对板栗栗红蚧若虫进行防治试验结果表明 ,杀虫效果以 40 %速扑杀 10 0 0倍液的防治效果最好 ,达 91%以上 ;用 2 5 %敌杀死 2 5 0 0倍液 ,40 %氧化乐果、5 0 %甲胺磷 10 0 0倍液 ,5 0 %敌敌畏 80 0倍液 ,效果次之 ,死亡率 70 %～ 84%;而用 2 0 %三唑磷乳油、90 %晶体敌百虫杀虫效果不佳 ,死亡率仅为 42 %。     

四种杀虫剂田间防治松沫蝉若虫试验

2016年4月在辽宁章古台通过注药和喷雾方式比较4种药剂田间防治松沫蝉Aphrophoridae flavipes若虫效果。结果表明:注射3.5%高效氯氰菊酯乳油对若虫的防治效果最好,施药21 d后校正死亡率88.52%;喷洒3.5%高效氯氰菊酯乳油1 000倍液对若虫的防治效果最好,施药7 d后校正死亡率91.29%。     

四种杀虫剂对橡胶盔蚧的防效试验

2004年8月进行4种杀虫剂对橡胶盔蚧的防效试验,结果表明40%杀扑磷乳油800倍液、2.5%杀蚧乳油 800 倍液、2.5% 蛛八蚧乳油 800～1　000 倍液、40% 氧化乐果乳油 800 倍液对橡胶盔蚧 1、2 龄若虫效果显著,14d 的防效均在91.3%以上;4种药剂的 800倍液对3龄若虫、成虫的试验结果,40%杀扑磷施药后 14d 防效为 64.7%,对成虫无效;对橡胶树无药害。     

防治油茶尺蛾药剂筛选试验

油茶尺蛾(Biston marginata Shiraki )是近年来广东省中山市阔叶混交林内出现的重要害虫.19种农药室内药效试验显示:15%茚虫威悬浮剂4 000倍液、10%除尽悬浮剂2 000倍液、16 000 UI/mg Bt可湿性粉剂1 000倍液、3.2%甲氨基阿维菌素苯甲酸盐5 000倍液、40%辛硫磷乳油2 000倍液、2.8%阿维菌素乳油10 000倍液和90%敌百虫晶体1 000倍液致幼虫死亡均达100%.在林间,15%茚虫威悬浮剂4 000倍液、10%除尽悬浮剂2 000倍液、16 000 UI/mg Bt可湿性粉剂1 000倍液、3.2%甲氨基阿维菌素苯甲酸盐5 000倍液、40%辛硫磷乳油2 000倍液和90%敌百虫晶体1 000倍液的杀虫效果均达100%,而2.8%阿维菌素乳油10 000倍液的杀虫效果为84.48%.     

七种农药对长鞘卷叶甲幼虫的毒力测定及林间防治试验

选用7种化学农药对长鞘卷叶甲2龄幼虫进行室内毒力测定,筛选出48%乐斯本乳油、4.5%高效氯氰菊酯乳油和90%杀虫单可溶性粉剂等3种农药的毒力较好,并应用于林间幼虫防治试验。试验结果表明,分别使用乐斯本、高效氯氰菊酯和杀虫单的2 000倍液进行喷雾防治效果较理想,可产生73%~85%的杀虫效果;乐斯本和高效氯氰菊酯用根灌法与注干法进行防治没有任何杀虫效果;杀虫单也能产生相对较强的杀虫效果,400倍液根灌效果为56.6%,40倍液注干效果为45.8%,可适当应用于林间防治幼虫。     

草履蚧防治试验

草履蚧在连云港地区1 a发生1代,以卵在卵囊内于土中越冬,危害杨树等寄主26种.草履蚧的天敌有大红瓢虫和黑红缘瓢虫2种,以幼虫取食草履蚧若虫.防治试验结果表明,在2月上中旬若虫上树前在树干上缠胶带阻隔若虫上树,阻隔率98%以上;6月上中旬,于树干基部周围培松土诱集成虫产卵,防治率90%以上;用20%吡虫啉20倍液注射防治,杀虫效果在90%以上;在小树树干上用20%吡虫啉原液直接涂刷毒环,杀虫率在98%以上;分别用50%辛硫磷、50%敌敌畏、25%扑虱灵可湿性粉剂等各1 000 倍液及果树宝200倍液进行喷雾防治,施药后48 h(扑虱灵7 d),校正防效均在95%以上.     

镇安县板栗园栗毒蛾防治试验

栗毒蛾在镇安县1年发生1代,发生较为普遍,平均有虫株率75.8%,每株虫数41.9头,可造成严重危害。防治试验研究表明,冬季刮除卵块,灭卵率为92%,基本上能控制虫害大发生;5月中旬至6月上旬,用40%氧化乐果乳油40倍液涂环防治,杀虫效果为87.48%;在幼虫1~3龄时,喷洒青虫菌0.1亿孢子/ml和杀螟杆菌1亿孢子/ml菌液,杀虫效果分别为87.5%和83.3%,杀虫效果明显;5月上旬卵孵化时喷洒50%敌敌畏乳油1 000倍液、2.5%溴氰菊酯乳油2 000倍液、25%灭幼脲3号悬浮剂500倍液,防治效果分别为92.86%、95.2%、92.18%,均在92%以上;本试验不同防治方法均可起到有效防治效果。     

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.     

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.