胡瓜钝绥螨控制苹果山楂叶螨的研究

采用室内不同温度下用山楂叶螨饲养胡瓜钝绥螨的方法,研究了胡瓜钝绥螨的生长发育史,通过田间释放胡瓜钝绥螨,进行了生物防治山楂叶螨的效果研究,并同化学防治进行了对比试验。结果表明,在方法得当的情况下,胡瓜钝绥螨完全可控制苹果山楂叶螨。     

果树二斑叶螨的发生与防治

二斑叶螨属蛛形纲,蜱螨亚纲,螨目,叶螨科,又名二点叶螨、白蜘蛛。二斑叶螨是一种几乎遍布于全世界的害螨,据中国农科院董慧芳等研究,在20世纪80年代以前,在我国没有该螨的分布,以往的很多记载均为误定。二斑叶螨可能是在20世纪     

螨死净防治三种叶螨田间试验

螨死净防治三种叶螨田间试验张守友，曹信稳（河北省农林科学院昌黎果树研究所）用２０％螨死净可湿性粉剂２０００倍液，防治苹果全爪螨、山楂叶螨和二点螨，１０—３１天内防治效果分别为：苹果全爪螨成螨３７５—９４．２￣Ｘ８４．６％，幼若螨６８—９４．９￣Ｘ８１...     

多种杀螨剂对山楂叶螨和二斑叶螨的杀卵效果比较

室内进行11种杀螨剂常用剂量对山楂叶螨和二斑叶螨的杀卵效果比较试验.结果表明:对山楂叶螨的杀卵效果表现为螨即死>哒螨酮>甲氨基阿维菌素苯甲酸盐>尼索朗>四螨嗪>螺螨酯>氟虫脲>炔螨特>阿维菌素;对二斑叶螨的杀卵效果为甲氨基阿维菌素苯甲酸盐>螨即死>三唑锡>尼索朗>炔螨特>阿维菌素>螺螨酯.三唑锡和毒死蜱对山楂叶螨杀卵效果很低.哒螨酮、四螨嗪对二斑叶螨杀卵无效.     

叶螨天敌控制苹果叶螨为害的效应

在北京巨山国营农场苹果园用田间笼罩排除天敌的方法研究了叶螨天敌(小花蝽草蛉和六点蓟马等)控制叶螨为害的效应。结果表明:在不同时期天敌对叶螨的控制作用不同。自5月下旬至7月下旬,天敌对叶螨的控制作用逐渐加强。在生长季早期,天敌控制叶螨为害的作用较小。天敌对叶螨作用的时间越长,对其控制作用越强。在0.2～3头/叶雌成螨密度下,天敌的控制效应呈S型曲线,2米/叶雌成螨是天敌的最佳作用密度。     

克螨特乳油防治苹果害螨的田间药效试验

用杀螨剂40％克螨特乳油进行了防治苹果山楂叶螨、二斑叶螨的田间试验，结果表明，克螨特1500－2500倍液对苹果山楂叶螨的防治效果为59．2％－96．8％，克螨特1500－2000倍液对苹果二斑叶螨的防治效果为63．9％－85．3％，与其他常用杀螨剂阿维菌素和扫螨净的效果相当。     

温度对朱砂叶螨实验种群生长的影响

在室内15～35℃恒温条件下,采用菜豆叶片饲养朱砂叶螨,分别组建实验种群生命表,分析温度对朱砂叶螨种群动态的影响。结果表明:朱砂叶螨全世代的发育起点温度和有效积温分别为11.2877℃和157.0658d.℃,各虫态发育历期均随温度的升高而缩短。并通过生命表资料统计出不同温度下朱砂叶螨试验种群的内禀增长率(rm)、净增殖率(R0)、世代平均周期(T)、周限增长率(λ)和种群加倍时间(t)等种群动态参数。     

扫螨净对苹果树两种叶螨的药效试验

扫螨净对苹果树两种叶螨的药效试验陈修会，赵锦彪，王信远，芦洪仁，陈常青（山东省临沂地区农业局，２７６００１）（临沂市生建园林场）山楂叶螨是我国北方果树的主要害螨，受害叶片失绿以致黄化脱落。二斑叶螨（ＴｅｔｒａｎｙｃｈｕｓｕｒｔｉｃａｅＫｏｃｈ．）是近...     

二斑叶螨危害果树初报

<正> 近年来,在河北昌黎、甘肃兰州、天水等地的个别苹果园,相继发现一种绿色型叶螨危害果树,有时甚为严重,且有不断向外扩散蔓延的趋势。据笔者及国内外有关专家鉴定,现已明确该螨即为二斑叶螨(Tetranychusurticae Koch.)。二斑叶螨是世界性重要害螨。该螨分布     

二斑叶螨的发生与防治

二斑叶螨属蝉螨目叶螨科，又名二点叶螨、白蜘蛛、黄蜘蛛，是一种杂食性害螨。 1危害症状 近几年来，二斑叶螨在陕西省渭北地区等部分苹果园有不同程度发生，特别是2004-2006年，在多处苹果园相继发生。其中受害树轻者叶片失绿，重者叶片呈焦糊状，更为严重的叶片脱落，有的甚至枝条枯死。     

氮、磷、钾失调对“苏州青”青菜生长的影响

以"苏州青"为试验材料,采用室内盆栽砂培方法,营养液按霍格兰配方进行配置,研究氮、磷、钾失调对其生长的影响.结果表明:不同养分处理对"苏州青"青菜的出苗、株高、根长、叶片数、叶长、叶宽等形态指标及地上部和根系鲜重均有不同程度的影响,缺磷和缺钾会明显降低"苏州青"的出苗率,氮过剩对出苗的抑制作用最为明显.除缺氮促使植株根系伸长外,缺氮、缺磷和氮过剩处理均使"苏州青"各形态指标数值有所降低.磷过剩、钾过剩及养分完全处理的地上部鲜重显著高于缺氮、缺磷、缺钾和氮过剩.氮过剩、磷过剩、钾过剩及完全处理地下部鲜重显著高于缺氯、缺磷、缺钾处理,氮过剩、磷过剩、钾过剩、完全处理之间根系鲜重差别不显著,缺氮、缺磷、缺钾处理之间的根系鲜重差别也未达到显著水平.     

水分胁迫对‘赤霞珠’不同叶龄叶片光合特性的影响

【目的】探究水分胁迫对葡萄不同叶龄叶片光合及荧光变化规律的影响。【方法】以3 a(年)生‘赤霞珠’葡萄(Vitis vinifera‘Cabernet Sauvignon’)为试材,由黎明前叶片水势(ψb)反映胁迫程度,设置对照(无水分胁迫,CK)、中度水分胁迫(T1)和重度水分胁迫(T2)三个处理,测定‘赤霞珠’葡萄新梢不同叶龄叶面积、叶片光合参数、叶绿素荧光参数及Ru BP活化酶和果糖-1,6-二磷酸酯酶活性。【结果】葡萄叶片叶龄为80 d时,叶面积趋于稳定,T2显著降低了各叶龄叶片的面积,T1与CK无显著性差异;葡萄叶片SPAD值随叶龄的增加而增大,且T1增加了各叶龄叶片SPAD值,T2则降低;Pn、Gs、Tr、Ru BP活化酶和果糖-1,6-二磷酸酯酶活性随葡萄叶片叶龄的增加均呈先上升后下降的趋势,并且随水分胁迫程度的增加下降程度增大;水分胁迫不同程度地降低了各叶龄叶片Fv/Fm、Yield、ETR、q P,而Fo显著增加,T2增加了各叶龄叶片的NPQ,但随着叶龄的增加,T2叶片NPQ又显著低于其他两个处理。【结论】随‘赤霞珠’葡萄叶片叶龄的增加,光合能力呈先上升后下降的趋势,当葡萄叶片叶龄为60~90 d时,光合能力最强。水分胁迫降低了各叶龄叶片的光合效率,重度水分胁迫会阻碍葡萄幼龄叶片的正常发育,并加速老龄叶片的衰老。     

广西特有药用植物弄岗唇柱苣苔叶插繁殖研究

对广西特有弄岗唇柱苣苔叶片进行不同扦插方式和不同激素浓度处理的繁殖试验。结果表明:用全叶进行扦插,扦插成活率最高;激素种类和浓度对弄岗唇柱苣苔叶片的扦插均有影响,其中IAA 100 mg/L和NAA 100～150 mg/L处理能获得较好的扦插成活率、生根效果及子株数量。     

光强和水分胁迫对姜叶片光合特性的影响

 为探讨根际供水状况与姜叶片需光特性的关系,通过模拟干旱与遮光（50%）交互处理,研 究了自然光照正常供水（T1）、遮光正常供水（T2）、自然光照干旱（T3）、遮光干旱（T4）等对姜叶片光 合参数及叶绿素荧光参数的影响。结果表明,试验处理过程中,T1、T2 姜叶片Pn 无显著变化,而T3、 T4 均持续降低,且降幅以T3 较大;随处理时间的延长,T1、T2 的Ci 及Ls 未发生显著变化,而T3、T4 分别在胁迫1 d、3 d 后,其Ci 即升高而Ls 降低,表明胁迫初期T3、T4 姜叶片Pn 的降低主要为气孔限制, 而后期则以非气孔限制为主;处理6 d 时,尽管各处理姜叶片Pn 在午间均显著降低,但降幅以T3、T4 较 大,尤其T3 在午后未出现第二峰值,而T1、T2、T4 均表现为双峰曲线变化。试验处理过程中,T1、T3、 T4 姜叶片Fv/Fm 持续降低,NPQ 升高,但变幅以T3 较大,T4 次之,T1 较小,T2 则无显著变化;处理6 d 时,虽然各处理姜叶片Fv/Fm、ФPSⅡ、qP 均在午间显著降低,NPQ 显著升高,但变幅以T3 较大,T4、 T1 次之,T2 较小。表明干旱胁迫对姜叶片光化学效率的影响大于自然光照胁迫,而遮光则可缓解干旱胁 迫。     

Streambed landscapes: evidence that stream invertebrates respond to the type and spatial arrangement of patches

The availability and spatial arrangement of habitat patches are known to strongly influence fauna in terrestrial ecosystems. The importance of patch arrangement is not well-studied within running-water systems where flow-induced movements of patches and of fauna could decouple habitat characteristics and faunal habitat preferences. Using small, stream-dwelling invertebrates, we asked if fauna in such systems can distinguish among patch types and if patch arrangement at their `landscape scale' (i.e., within a streambed across which they move and forage) can be linked to faunal abundance. We quantified the spatial distribution of sand and leaf patches at multiple sites on a streambed at regular intervals over a 1 yr period, estimated faunal abundance in the two patch types, and experimentally determined if faunal colonization varied among leaf patches that were similar structurally but differed in their potential microbial food resources. We show that despite their small size and limited swimming abilities, these stream invertebrates did respond to patch type, that specific characteristics of an individual patch influenced faunal colonization, and that the spatial arrangement of patches on the streambed was linked to field abundances. Larval chironomids and adult copepods were more abundant in leaves than in sand and preferentially colonized leaf patches made with rapidly decomposing leaves that harbored higher microbial (bacteria and fungi) abundances over leaf patches with more refractory leaves and lower microbial abundances. Further, statistical models that included spatially-explicit data on patch arrangement (e.g., patch contagion, distance between patches) explained significantly more variation in faunal abundance, than models that included only nonspatial information (e.g., date, time since last flood). Despite the fact that these fauna live in a highly dynamic environment with variable flow rates during the year, unstable patch configurations, and seasonal changes in total abundance, our findings suggest a need for aquatic ecologists to test the hypothesis that small-scale landscape attributes within streams (e.g., leaf patch aggregation) may be important to faunal dynamics. If patch aggregation has negative consequences for stream biota, streambed `landscapes' may be fundamentally different from many terrestrial landscapes due to the inherent connectivity provided by the water and the over-riding importance of patch edges. Regardless of these differences, our findings suggest that the spatial configuration of patches in a landscape may have consequences for fauna even in highly dynamic systems, in which patches move and fauna periodically experience high levels of passive dispersal.     

圆头蚊母扦插繁殖试验

将吲哚乙酸、萘乙酸和2,4-二氯苯氧乙酸分别配成500、1 000、1 500和2 000 mg/L4种不同的浓度,于春、夏季对圆条蚊母插条进行促根处理,并以清水为对照,以期寻找提高圆头蚊母扦插成活率的措施.结果表明:3种不同的生根剂及同一生根剂的不同浓度处理枝条后对扦插生根率的影响都存在显著差异.吲哚乙酸(IAA)和萘乙酸(NAA)能提高插条生根率,2,4-二氯苯氧乙酸(2,4-D)则起到抑制作用.以500 mg/L的IAA浸30 s的半硬枝扦插生根率最高,达78％.     

水分胁迫对荔枝幼树根系与梢生长的影响

以盆栽沙培1年生荔枝空中压条苗为试材,研究了水分胁迫对荔枝幼树根系和梢生长的影响以及二者的相互关系。3个处理为:沙体积含水量为7.5%(严重缺水),15.0%(一般缺水),22.5%(充分供水)。结果表明:水分胁迫严重抑制荔枝幼树地上部分和各级侧根的生长,使地上部枝梢生长严重受阻,叶片数量、平均叶面积、叶片厚度均显著变小;根总干重、侧根长度、根表面积显著减少。水分胁迫下促进须根的生长,须根的长度、根表面积比水分充足时显著增加。水分胁迫时叶片淀粉含量下降,而根系积累更多的淀粉。比较不同处理的根梢比发现,干旱对根系生长的抑制作用比枝梢更显著。     

Effects of water deficit on olive trees cv. Chemlali under field conditions in arid region in Tunisia

Water scarcity in the Mediterranean basin in addition to the extension of irrigated lands is one of the main factors limiting agricultural development. The need for supplementary irrigation of the Chemlali olive cultivar (Olea europaea L.) during summer and autumn periods was investigated. Leaf water content, gas exchange parameters, fruit development and yield in rain-fed and in irrigated plants have been monitored in 12-year-old olive trees grown under environmental conditions in semi arid regions characterized by high temperatures and high light intensity. Trees were subjected to three irrigation treatments, T0, T1 and T2 corresponding respectively to 0, 33 and 66% of crop evapotranspiration (ET_c) by a drip irrigation system. The water deficit during the summer (from June to August) led to the decrease of soil moisture, leaf water content and gas exchange parameters. Irrigated trees showed the same slow activity in the three summer months as the rain-fed trees. For all treatments, net CO₂ assimilation, stomatal conductance and transpiration rates were markedly decreased by environmental conditions (high air temperature and high light intensity) during the summer period. At the partial active growth phase of the Chemlali olive cultivar (September–November), a significant re-increase in all parameters was observed. However, net photosynthesis and stomatal conductance of control plants (T0) were, respectively, 57 and 40% lower than those of plants conducted under milder water contribution (T1). The decrease of physiological activity in irrigated plants during hot and dry (summer time) and cold (winter) seasons was a clear evidence that water supply during such periods will be without a great benefit for photosynthetic activity, and thus growth, if applied under critical conditions inducing the rest phase of the plant. The non-statistically significant slight differences as well in photosynthetic performances activities (Pn, Gs and E rates), as in olive production between the two irrigated treatments will not cover the expenses of water loss when applying irrigation at 66% of ET_c especially in arid region characterized by scant and irregular rainfall. On the light of these results, we can conclude that the irrigation of this species during the vegetative growth phase (in spring and autumn), and stopping it during the olive rest phase (in summer and winter) could be recommended at least under the experimental conditions of this study; and that the contribution of 600 mm of water per year (33% of ET_c) can respond to the needs of the Chemlali olive cultivar in a semi arid region without impairing photosynthetic activity and olive production.     

复混基质对南疆日光温室番茄根区环境、果实品质及产量的影响

以粗砂、蛭石、菇渣、树叶、锯末为基质材料,不同材料按体积比复配后形成10种复混基质,以粗砂基质为对照,进行"欧曼"品种番茄栽培试验。采用相同尺寸栽培槽填充基质、无土栽培水肥管理及田间整枝管理措施,研究了不同配比基质理化性质、根区温度与根区湿度,及其对番茄果实品质及产量的影响。结果表明:复混处理后基质的容重较CK显著降低,孔隙度较CK显著升高;复混基质能改善根区的温湿环境,不同处理平均温度较CK提高了0.35~1.24℃,平均湿度较CK提高1.86%~13.32%;对比果实产量和品质发现T6与T8处理总体表现最好,果实硬度、单果质量、单株产量、单株结果数、增产率均优于其它处理,维生素C、可溶性蛋白质、有机酸含量也均处于较好水平,综合比较发现T6处理(粗砂∶蛭石∶菇渣∶树叶∶锯末=2.5∶2.5∶1∶2∶2)和T8处理(粗砂∶蛭石∶菇渣∶树叶∶锯末=2.5∶2.5∶1∶1∶3)能为番茄生长提供良好生长环境,并能提高番茄的产量及品质。     

Citrus rootstock responses to water stress

Tolerance to drought-stress (DS) of the citrus rootstock Forner–Alcaide no. 5 (FA-5) was tested and compared with that of its parents, Cleopatra mandarin (CM) and Poncirus trifoliata (PT). Nine-month-old seedlings of CM, PT and FA-5 and 15-month-old grafted trees of ‘Valencia’ orange scions on these three rootstocks were cultivated in sand under glasshouse conditions and irrigated with a nutrient solution. Plants were drought-stressed by withholding irrigation until leaves were fully wilted. Survival time of both seedlings and grafted trees under DS was linked to the water extraction rate from the soil, which depended mainly on leaf biomass and on transpiration rate. Seedling responses to DS affecting leaf water relationships and gas exchange parameters varied among genotypes. FA-5 seedlings survived longer than the other seedlings, maintaining the highest levels of water potential, stomatal conductance, transpiration rate and net CO₂ assimilation towards the end of the experiment, when water stress was most severe. Thus, FA-5 was more resistant to DS than its parents (CM and PT). Moreover, rootstock affected the performance of grafted trees under water stress conditions. The higher drought tolerance induced by FA-5 rootstock could be related to the greater osmotic adjustment (OA), which was reflected by smaller reductions in leaf relative water content (RWC) and in higher turgor potentials and leaf gas exchange than the other rootstocks.