泡桐主要病虫害及防治

<正>泡桐Paulownia fortunei又称桐树,玄参科Scrophulariaceae,泡桐属Paulownia。泡桐是中国特产的速生用材树种。落叶乔木,小枝粗壮。喜光,生长甚快。木材轻软、结构均匀、不翘不裂、耐腐耐磨、易于干燥和加工,供制箱匣、乐器、救生器械、瓶塞等用。小枝可制炭笔。又为绿化树、行道树。泡桐的叶、花、果、皮均可入药,具消炎、止咳、利尿、降压等功能。叶和花营养丰富,是良好的饲料和肥料,种子含油,可制肥皂。     

茶入联中香隽永

茶之为饮,发乎神农氏,闻于鲁周公。中国是世界上较早发现和利用茶叶的国家之一,人们在长期的饮茶过程中,给茶渗入了丰富的文化内涵,逐渐形成了独特的文化现象。茶与文化关系至深,涉及民俗、宗教、文学、美术、书法、诗词、楹联、旅游、戏曲、音乐、歌舞等诸多领域。楹联是我国特有的文化艺术形式,种类繁多,茶联便是其中之一。楹联始于五代,亦称楹贴、对联,是悬挂或粘贴在柱身、门上的联语,由一联对偶句组成,以讲究工整的对仗,有“字数相等、词性相同、结构相应、句式相似、内容相关、平仄相对”的要求。     

巴西农药市场特点

巴西是南美洲最大的国家,国土面积为851.49万平方公里,约占南美洲总面积的46%,居世界第五,仅次于俄罗斯、加拿大、美国与中国。巴西是农业大国,主要农作物有大豆、甘蔗、玉米、稻米、咖啡、子棉、木薯、柑桔、烟叶、芸豆、香蕉、小麦、马铃薯、西红柿、葡萄等。其中,巴西是世界第一大咖啡生产国和出口国、最大的蔗糖生产和出口国、第二大大豆生产和出口国、第三大玉米生产国。全国可耕地面积约4亿公顷,被誉为"二十一世纪的世界粮仓"。巴西于2008年代替美国成为全球最大的农药市场,2011年在甘蔗、棉花、咖啡、小麦、大豆和玉米等作物需求量的驱动下,农药销售额达到新高。根据巴西国家农药工业联     

二十四节气话农事

古有谚语:"春雨惊春清谷天,夏满芒夏暑相连,秋处露秋寒霜降,冬雪雪冬小大寒"来描绘中国的立春、雨水、惊蛰、春分、清明、谷雨、立夏、小满、芒种、夏至、小暑、大暑、立秋、处暑、白露、秋分、寒露、霜降、立冬、小雪、大雪、冬至、小寒、大寒二十四节气,可见节气变化对于农业生产的重要性。在人类从事农业生产的早期,由于播种收获等农事活动,已经认识到春生夏长秋收冬藏的规律。中国秦汉便有了完整的二十四节气,用以指导农业生产;东汉《四民月令》记述按月和节气安排农事活动;北魏《齐民要术》阐明以节气为依据安排耕、种、收。后世各代也都以二十四节气决定农时的依据。我们借鉴前人的经验,凭借科学的态度,应读者的要求特别开辟《二十四节气话农事》专题,对于广大农民朋友正确运用二十四节气,掌握天气气候规律,科学安排日常生产生活,顺应农时、不违农时,破除迷信、科学种田,争取农业丰收,都有着重要的参考作用。     

外来入侵植物飞机草对生态系统的危害和防除

飞机草是一种外来入侵物种,是世界性的恶性有毒植物,对生物多样性造成很大的危害。现广泛分布于热带亚洲、非洲及澳洲等30多个国家。在我国,主要入侵海南、云南、贵州、广东、广西及港澳台等省区。它侵占林地、草场、农田,危害农、林、牧业,危及人、畜健康,严重危害了生态系统。因此,研究它危害的根源,选用其中一种方法或者综合利用几种方法进行防除。目前国内外防除措施有机械防除、替代防除、化学防除、生物防除、综合防除等。     

20%氯虫苯甲酰胺防治莲藕食根金花虫药效试验

莲藕食根金花虫Donacia provosti Fairmaire俗称地蛆,属鞘翅目叶甲科。成虫绿褐色,有金属光泽,长度6～9mm。幼虫白色蛆状,成虫和幼虫均能为害作物。主要为害莲藕、莼菜、茭白、水稻、矮慈姑、稗、眼子菜、鸭舌草、长叶泽泻等水生植物。该虫在我国分布广,是深水藕地区的重要害虫,为害严重     

杂草图谱

罗布麻（茶叶花、野麻、红麻、茶棵子、吉吉麻、草夹竹桃、野茶） 形态特征 成株全株具乳汁。直根粗壮。茎直立,圆柱形,多分枝,枝条通常对生,无毛,紫红色或淡红色。叶对生,长椭圆形,先端急尖或钝,基部楔形或圆形,叶柄腋间有腺体。聚伞花序顶生,花冠筒状钟形。粉红色或浅紫红色。     

清水县麦田杂草发生情况调查初报

清水县麦田杂草有12科26种,其中双子叶杂草占61.5%,禾本科杂草占19.2%,蕨类杂草占19.3%。相对多度达10以上的麦田杂草依次为离蕊芥、麦瓶草、芥菜、雀麦、离子草、蚤缀、王不留行、播娘蒿、苦苣菜、狗尾草、夏至草等11种。其中离蕊芥、麦瓶草、芥菜的相对多度分别为55.3、36.89、和25.01,为麦田的优势种群。针对发生种类,应采取优化作物布局,提高栽培管理水平,合理使用除草剂,以达到综合除草效果。     

桔小实蝇在湖北省的适生性分析

桔小实蝇Bactroceradorsalis（Hendel）俗称黄苍蝇,果蛆,英文名又称orientalfmittly（东方果实蝇）,属双翅目,果实蝇科,目前主要分布在热带和亚热带地区。国外分布于美国、澳大利亚、印度、巴基斯坦、日本、菲律宾、印尼、泰国、越南等,国内广东、广西、福建、四川、湖南、台湾等省。幼虫在果内取食为害,常使果实未熟先黄脱落,严重影响产量和质量。除柑桔外,尚能为害芒果、番石榴、番荔枝、阳桃、枇杷等200余种果实。     

公元600-2000年宝鸡地区洪涝灾害发生规律

通过对历史文献资料的搜集和整理,对公元600-2000年宝鸡地区洪涝灾害变化阶段、趋势、等级分布和成因进行了研究。结果表明：宝鸡地区洪涝灾害可划分为轻度涝灾、中度涝灾、大涝灾、特大涝灾4级,以中度和大涝灾为主,占灾害记录总数的71.55%,特大洪涝灾害发生较少,占灾害记录总数的8.94%。公元600-2000年的1 400 a可以分为14个洪涝灾害发生阶段: 10、11、12、13、14、15世纪为无洪涝灾害或极少洪涝灾害发生阶段,7、8、9、16、17、18、19、20世纪为洪涝灾害多发阶段。洪涝灾害发生频次具有空间差异,9个县区由多到少依次为：宝鸡、扶风、千阳、凤翔、凤县、陇县、麟游、岐山、眉县。最多与最少之间相差26次,空间差异较大。洪灾集中于夏、秋两季。宝鸡地区洪涝灾害的发生主要是由地理位置、降水和气候异常波动以及人类活动综合因素影响的结果。     

烟草气候斑病病因探讨

 通过1990~1994年研究,明确了广东省南雄县烟草气候斑病是由臭氧(O₃)伤害所致,与土壤锰肥供应状况、酸雨、SO₂等因素无关。试验表明单一低温因子,不会引起气候斑,但却是一个主要诱因。     

Calcium fertilizers induce soil suppressiveness to <Emphasis Type="BoldItalic">Phytophthora cinnamomi</Emphasis> root rot of <Emphasis Type="BoldItalic">Quercus ilex</Emphasis>

Based on the observation that the root disease caused by P. cinnamomi on Q. ilex has a low incidence and severity in soils with medium-high Ca²⁺ content, we studied the ability of Ca²⁺ fertilizers to induce soil suppressiveness to the pathogen. Studies on cultures of P. cinnamomi exposed to different Ca²⁺ fertilizers in vitro showed significant inhibition of sporangial, chlamydospore and zoospore production at millimolar concentrations while mycelial growth was mainly unaffected. Experiments performed with artificially infested soil showed that some Ca²⁺ fertilizers induce a significant decrease on chlamydospore viability. Additionally, greenhouse experiments using artificially infested soils showed a significant reduction of foliar and root symptom severities in Holm oak seedlings growing in soils amended with Ca²⁺ fertilizers. We suggest that limestone amendments in oak rangelands could enhance the suppressiveness of soils to P. cinnamomi, and it is likely that the inhibition of sporangial production was the main mechanism involved.     

Soil Fertility Variability and Constraints on Village Scale Transects in Northern Burkina Faso

Soil variability has a profound impact on crop yields in low-input agriculture. The objectives of this study were to examine soil fertility variability and to identify potential soil constraints relating to farmers' conditions for agricultural production in the Sahelian zone of northern Burkina Faso. Surface soil (0-20 cm) and subsoil (20-100 cm) were sampled from 25 pedons on village-scale transects embracing three genetic soil units: two generations of sandy dune soils showing incipient development; a complex unit of clayey pediplain soils with duplex properties showing both alkaline and acid subsoil reaction; and hydromorphic, clayey valley bottom soils. Particle size distribution, pH, electrical conductivity, cation exchange capacity, exchangeable base cations and acidity, soluble base cations, organic carbon, nitrogen, total and available phosphorus, moisture constants, and bulk density were determined. Contents of organic carbon, total nitrogen, total and available phosphorus,and exchangeable potassium are low in all soils and are presumably major constraints.The sodium influenced clayey soils show high absolute variability; properties that vary are subsoil clay (5.8-38.5%), pH (5.8-10.0), cation exchange capacity (4.49-24.81 cmolc kg1), exchangeable sodium percentage (0-26), as well as electrical conductivity, structure, consistency, and available water holding capacity. The sandy soils are homogeneous and not as acid as elsewhere in the Sahel, presumably due to a dust influx. The soil fertility is generally low but highly variable, implying that constraints within production units may consist of multiple com binations of adverse chemical and physical properties, conceptually consistent with the low and variable millet yields. The variability also implies that soil character ization depends on the design of soil sampling, that average values are of doubtful use, that application of chemical fertilizers will produce very different results, and that there is no general scheme for correcting soil fertility. The application of lives tock manure will continue to be the best strategy for sustaining soil productivity.     

Relations entre la vitesse de dégradation du propyzamide et les propriétés physicochimiques des sols

Relationship between rate of propyzamide degradation and physico-chemical properties Propyzamide was incubated in 29 different soils at a soil moisture content of 25%. The degradation of the herbicide followed first-order kinetics. The rate of propyzamide degradation was correlated with soil resistivity. Addition of mineral fertilizers inhibited propyzamide degradation.     

Relationships between substituted urea herbicides and soil urease activity

Fenuron, monuron, diuron, siduron, linuron and neburon were tested for their inhibition of soil urease activity in order to investigate relationships between fertilizers and herbicides. The inhibition of urea hydrolysis in the selected soils was 10–33% for fenuron, 10–39% for monuron, 10–35% for diuron, 8–38% for siduron, 9–36% for linuron and 12–30% for neburon. In the field greater effects might be expected since the fertilizer/herbicide ratio would be lower than the one considered here. Some agronomic aspects of the relationship between fertilizers and herbicides are discussed.     

草炭保水机制的初步研究

灌溉是干旱区农业存在与发展的必要条件。如何提高灌溉水的利用率，及如何保持土壤中的水分以保障作物需求，是本区农业研究的重要问题。通过测定并分析不同草炭处理土壤的表层（30cm)含水量，物理性质及作物产量，本文探讨了草炭处理土诘的水分动态变化及草炭的保水机制，观测数据显示，与对照组相比，在观测期间，2%加拿大草炭处理土壤含水量提高3.96%;2%石河子草炭处理土壤含水量提高3.43%。进一步的研究表明，草炭对土壤水分的保持机制，不仅是因为其所具有的巨大持水能力，对土壤物理性质的改善，也是其保水机制之一，由于大空隙的增加，切断了毛管水的上升，从而降低了土壤表面的水分蒸发，在下层土壤中保持了更多的水分。     

土壤添加生物质炭和施肥对褐飞虱生长发育和生殖的协同效应

为评价土壤添加生物质炭控制褐飞虱Nilaparvata lugens的应用潜力是否受到施肥的影响,在室内按析因设计进行添加生物质炭和施肥的盆栽试验,观察在生物质炭(0、10、50 g/kg)×施肥(不施肥、尿素、复合肥)处理后的水稻上取食的褐飞虱生长发育和生殖表现。结果表明,添加生物质炭对褐飞虱若虫发育历期的影响不因施肥而变化,少量(10 g/kg)和足量(50 g/kg)生物质炭处理下的若虫发育历期分别为13.7 d和13.9 d,但均比不添加生物质炭对照(12.9 d)显著延长。添加生物质炭对若虫存活率的影响与施肥有关,在施复合肥条件下生物质炭处理不影响存活率,而在施氮肥条件下足量生物质炭处理使若虫存活率(69.9%)比少量生物质炭处理(88.8%)显著降低。添加生物质炭对成虫长翅型比例的影响取决于施肥,虽然不施肥条件下添加足量生物质炭可使长翅型比例从少量处理的10.9%增至足量处理的40.2%,但在施复合肥或氮肥条件下,生物质炭不影响长翅型比例。添加生物质炭对褐飞虱生殖力的影响与施肥有关,在施复合肥条件下生物质炭对其生殖力影响不显著,在施氮肥条件下足量生物质炭处理的产卵量平均为170.6粒,较不添加生物质炭对照(290.3粒)和少量生物质炭处理(309.3粒)显著减少。研究结果表明,土壤添加生物质炭对褐飞虱存活和生殖的不利影响因施肥种类不同而有一定的变化。     

Effect of synthetic and organic soil fertility amendments on southern blight, soil microbial communities, and yield of processing tomatoes

ABSTRACT Soil fertility amendments, including composted cotton-gin trash, swine manure, a rye-vetch green manure, or synthetic fertilizers, were applied to subplots and tillage on bare soil; or tillage followed by surface mulch with wheat straw were applied to main plots to determine the effect on the incidence of southern blight caused by Sclerotium rolfsii, yield of processing tomato, and soil microbial communities. The amendment-tillage interaction was significant in 1997 and disease incidence was 67% in tilled bare soil receiving synthetic fertilizers; whereas disease incidence was 3, 12, and 16% in surface-mulched plots amended with a composted cotton-gin trash, swine manure, or a rye-vetch green manure. The amendment effect was significant in 1998, and disease incidence was 61% in plots receiving synthetic fertilizer and was 23, 44, and 53% in plots receiving cotton-gin trash, swine manure, or rye-vetch green manure, respectively. In 1997, yields were highest in tilled surface-mulched plots amended with synthetic fertilizers, cotton-gin trash, or swine manure, respectively. In 1998, yields were low in all plots and there were no significant differences in yield due to treatment. Propagule densities of antagonistic soil fungi in the genus Trichoderma were highest in soils amended with composted cotton-gin trash or swine manure in both years. Propagule densities of fluorescent pseudomonads in soil were higher in plots amended with organic amendments than with synthetic fertilizers in both years. Propagules densities of enteric bacteria were elevated in soils amended with raw swine manure biosolids in both years. Our research indicates that some organic amendments, such as cotton-gin trash, reduced the incidence of southern blight in processing tomato and also enhanced populations of beneficial soil microbes.     

西北干旱区土壤的生态特征与变化

本文利用详实的资料,分析了干旱区主要土壤类型、分布及其生态意义,土壤的理化性状、养分特征以及在盐碱化、沙化和灌耕条件下的变化,并论证了这种变化在生态功能上的影响。其结果表明：①干旱土壤分布具明显空间垂直地带性及径向分布规律。极端干旱条件下的暖温带棕漠土的生态功能最差,其他土壤的生态功能排序依次为灰棕漠土＜ 灰漠土＜ 灰钙土（棕钙土）＜ 灌耕土＜ 草甸土类;②土壤生态性能在灌耕,风沙及盐碱化条件下发生显著变化,耕灌条件下使高生态性能的土壤逐渐退化而低生态性能土壤有所改善;盐碱化和风沙化的结果使土壤贫瘠化和粗质化,生态性能严重退化;干旱区平原土壤的生态特征与变化规律决定了其具有潜在荒漠化倾向。对干旱区土壤和生态特性及其变化的认识,是干旱区水土资源合理利用与生态保护的基础     

北疆棉花精准种植施肥指标量试验研究

建立在试验地土壤背景数据库的基础之上,将不同空间单元(时间空间和地理空间)的产量数据与其他多层数据叠合分析,以棉花生长模型、棉花营养平衡施肥专家系统为支持,提出了北疆棉花精准施肥的指标。采用精准施肥指标的试验结果表明:(1)与全部化肥一次足量深施比,667m2平均节约化肥费用22.5元,667m2增产10%左右;(2)与化肥和有机肥全部作基肥深施相比,前者比后者667m2平均节约化肥成本36元,籽棉增产10%-15%;(3)用滴灌专用肥进行的灌溉施肥,氮的利用率在70%左右,磷的利用率在31%-34%左右。这一结果基本接近国际水平(75%和35%)。