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1.
苏云金杆菌群(Bacillusthuringiensis)防治农田蛴螬有较好效果,其经济效益和生态效益较常用化学农药优越。花生田5年试验示范效果较为稳定,八号菌(B.thuringiensisVarKurstaki)拌种平均灭虫效果为76.7%,保荚效果为70.9%,持效期可达80天以上,菌药防治的药本与净收益之比为1:42.2,而化药防治的为1:23.5。大豆田试验,每亩用规吨300gB·t乳剂防治,灭虫效果可达67.7%,增产效果可达49.8%,优于辛硫磷防治。  相似文献   

2.
为有效地控制苹果白粉病的危害,筛选出适合当地生产上防治苹果白粉病的高效药剂.本研究选用10种新型高效低毒药剂,在林芝市巴宜区米瑞乡果园开展了杀菌剂对苹果白粉病田间药效试验.结果表明,40%腈菌唑WP在第3次药后14 d防效达到80%以上,效果最好;50%硫磺JG、 30%己唑·乙嘧酚ME、 300 g/L醚菌酯·啶酰菌悬浮剂、 80%硫磺WG 4种药剂在第3次药后14 d防效也能达到70%以上.因此,以上5种药剂均可作为防治苹果白粉病的首选药剂,可在果园内交替使用.研究结果旨在为该病害的有效防控提供理论依据.  相似文献   

3.
1959—1960年作者等在江西、湖南等地区配合大面积防治森林害虫之际,开展了DDT等化学药剂对于不同越冬时期的马尾松毛虫幼虫的毒效试验。据野外观察结果,将马尾松毛虫越冬幼虫划分为5个时期。即越冬前活动期、越冬前期、越冬期、越冬后期、越冬后活动期。试验证明:不同化学药剂对越冬松毛虫幼虫的毒效随着不同时期和温度条件而变化。就一般论:DDT的效果,在比较低温(日均温10—20℃)时特别显著;666及敌百虫的效果,在比较高温时(20℃以上)为显著。其中尤以敌百虫为更甚。DDT对不同时期幼虫的毒效大小为:越冬后期>越冬前期>越冬期>越冬前活动期>越冬后活动期≥夏季(4-5龄)幼虫;其中以越冬后期幼虫抵抗力最弱。从原则上论这是施药的最适宜时期,从25% DDT乳剂4,000倍稀释液在越冬后期(2,3月间)施用,毒效可达92%以上,用6,000倍稀释液亦达82%以上。如用γ6%可湿性666,800倍稀释液在越冬前、后期使用,毒效可达70-80%以上。50%敌百虫乳剂在温度20℃以上时(越冬前、后活动期)毒效显著增高。此时如用5,000-6,000倍稀释液喷洒,毒效可达70-80%左右。由此,作者认为:在长江以北,每年发生2代以下的松毛虫地区,可用DDT和666稀释液在越冬前、后期进行防治。长江以南,每年发生2代以上的马尾松毛虫地区,不但可用DDT、666来防治越冬前、后期幼虫;而且在幼树林地内越冬期的幼虫亦可防治。在上述地区内,敌百虫乳剂仅适于在越冬前、后活动期或夏季幼虫期温度较高时使用。就一般论,在越冬前期施用药剂时,如能选定在寒流侵袭之前喷射,效果更为显著。  相似文献   

4.
冬小麦蛴螬类混合种群为害损失及防治指标研究   总被引:5,自引:1,他引:4  
蛴螬类混合种群,主要指大黑鳃金龟Holo-.trichiaoblitaF、云斑鳃金龟PolyphyllachinensisFairmaire、暗黑鳃金龟HolotrichiaParallelaMotschulsky的幼虫,是陇东冬麦区为害较重的一大类地下害虫。一般为害冬小麦,造成缺苗或死苗率为5%~15%,严重者达30%左右,致使冬小麦产量下降、损失较大,为了制定防治指标,1989~1991年笔者就蛴螬类混合种群(以下简称济错)为害冬小麦损失与防治指标进行了研究,现将结果整理如下。1研究方法选择技错密度较高,为害较重的冬麦田。地点在泾川县西高寺村塬地;土壤为肥力中等均匀的黑沙土;冬…  相似文献   

5.
应用11371复合剂防治人参锈腐病的研究   总被引:1,自引:0,他引:1  
人参锈腐病是栽培参的主要病害,发病率一般在60—80%,对栽培参的损失很大。由于该病是土传病害,而且致病菌复杂,多年来尚无较好的防治方法。本文介绍了使用抗生素11371为主的复合药剂防治人参锈腐病的情况;几年来田间防效稳定在45%以上,最高防效可达70%,并且用药当年可增产15%左右。  相似文献   

6.
采用高效液相色谱(HPLC)技术对在广州发现的鹅膏菌新种——致命鹅膏(Amanita exitialis)不同组织部位的肽类毒素(鹅膏毒肽和鬼笔毒肽)的含量进行了分析,结果表明,致命鹅膏是一种剧毒蘑菇,其毒素含量相当高,子实体中组织部位不同,毒素含量以及鹅膏毒肽和鬼笔毒肽在其中的分布也不一样,菌盖中的毒素含量最高,达8152.6μg/g干重,菌柄的毒素含量次之,为3742.3μg/g干重,菌托中的毒素含量最低,只有1142.5μg/g干重;在菌盖、菌柄和菌托中都以鹅膏毒肽为主,尤其以α-amanitin的相对含量最高,但从菌盖至菌柄到菌托,鬼笔毒肽尤其是Phallacidin的相对含量依次增加。  相似文献   

7.
【目的】为探索适用于愈纹萤叶甲Galeruca reichardti成虫的防治药剂室内毒力测定方法,并筛选其防治的有效药剂。【方法】分别采用浸虫法、浸叶法和胃毒触杀联合毒力法测定了8种药剂对其成虫的毒力,并通过大田试验进一步验证。【结果】浸虫法测得除虫菊素对愈纹萤叶甲成虫的毒力最高,其LC50值为68.24 mg/L;浸叶法测得氟啶虫胺腈的毒力最高,其LC50值为111.11 mg/L;胃毒触杀联合法测得氟啶虫胺腈的毒力最高,其LC50值为67.94 mg/L。其中,除虫菊素毒力值变化最大,浸虫法毒力是浸叶法的28.97倍,胃毒联合法毒力是浸叶法的17.83倍。蛇床子素、苦参碱在3种生测方法中毒力较低。田间试验结果显示,50%氟啶虫胺腈水分散粒剂562.5 g/hm2防治效果达94.90%,对韭菜苗保苗效果为81.45%,且显著高于其他药剂。【结论】3种毒力测定方法均可用于该虫的毒力测定,而从此虫的为害特点来看,胃毒触杀联合毒力法更能显示药剂的毒力性质。在愈纹萤叶甲成虫盛发期选择氟啶虫胺腈喷施可以有效减轻该虫为害。  相似文献   

8.
通过金龟子成虫在黑光灯下和田间的消长调查、蛴螬的田间定期挖查 ,初步摸清了闽南地区危害花生、大豆、甘薯、甘蔗等旱地作物的蛴螬种类有 2 6种 ,主要种类有 9种。明确了其主要蛴螬种类的生活习性与旱地作物互为相关。通过采用不同的药剂与不同方法进行防治试验 ,筛选出经济有效的药剂种类 ,并根据不同作物的生长特性和不同蛴螬种类的危害特点 ,确定了经济有效的防治适期 ,并制定了相应的防治技术措施  相似文献   

9.
为防治灵芝的哈茨木霉病害,对土壤细菌进行筛选,得到1株具有抑菌效果的菌株,编号为JSW-0601,初步测定了JSW-0601对哈茨木霉的抑菌效果,并与11种生防药剂进行对比,通过分子生物学方法和生理生化特性鉴定了JSW-0601的分类地位,确定了JSW-0601的发酵条件,对菌剂制备进行初步探究。细菌菌体制成的菌液对病原菌有抑制作用,其中20μL的菌液抑菌率为63. 33%,作为毒介质菌体原液的抑菌率最高可达94. 93%,2. 5%滤菌液抑菌率达30. 80%,20%灭菌液抑菌率也可达80. 20%,菌体分泌的胞外活性物质和化学物质均有较好的抑制效果。JSW-0601为短小芽胞杆菌,抑菌效果优于11种生防药剂,最佳发酵条件为0. 1%接种量、培养48 h,培养机制为麦芽糖0. 25%、蛋白胨1%、硫酸镁0. 5%,最优载体为硅藻土。筛选得到的短小芽胞杆菌对灵芝哈茨木霉病害的抑制作用较好,为灵芝木霉病害的生物防治提供科学参考,同时也为短小芽胞杆菌的应用提供了新方向。  相似文献   

10.
高尔夫球场不同功能区草地优势种蛴螬种群生态位分析   总被引:4,自引:0,他引:4  
研究了亚热带高尔夫球场不同功能区优势种蛴螬种群空间分布及时间和空间的生态位.结果表明,球场4种优势种草地蛴螬时间生态位宽度几乎均在0.9以上(除果岭Ⅲ区及Ⅳ区个别蛴螬种外),其中短草高地和果岭Ⅰ、Ⅱ区中4种蛴螬时间生态位宽度均最大,长草高地和果岭Ⅳ区的时间生态位宽度则最低.除浅棕鳃金龟垂直空间生态位宽度在球道4区均达0.8以上外,其它种蛴螬在球场各区普遍偏低(0.2~0.7).在球道和果岭4区中,4种蛴螬种对时间生态位相似性指数均高达0.8以上,垂直空间生态位相似性指数大多数蛴螬种对在0.1~0.6之间,球道以铜绿丽金龟与大绿金龟种对为最高(0.8以上),果岭则是铜绿丽金龟与大绿金龟、华南大黑鳃金龟与浅棕鳃金龟种对为最高(0.8以上).垂直空间分布上,球道和果岭各区中4种蛴螬主要活动于食源最为丰富的上、中层土壤空间(0~5和5~10cm),少数出现于球道部分区10~15cm土层中活动和取食,4种蛴螬几乎不在果岭10~15cm土层中活动和取食。  相似文献   

11.
稻田水面漂浮的杂草种子种类及动态   总被引:1,自引:0,他引:1  
为了揭示杂草种子的漂浮动态,并为探寻生态控草方法提供理论依据,我们于2005年6-11月,在南京沧波门稻作区调查了水稻种植前及生长后期田问杂草群落以及稻田灌水期间水面漂浮的杂草种子的种类及漂浮时间.结果表明,在水稻种植前及生长后期田间出现有15科24种杂草;可漂浮于水面的杂草种子有17科26种,与田间发生的杂草种类相同的共有18种,占所有32种杂草的56.25%.这些杂草主要隶属于禾本科、蓼科、毛茛科、报春花科、莎草科、菊科和雨久花科.田埂附近漂浮的杂草种类及种子数量均高于田中间;各类杂草种子的漂浮能力不一,其中菵草(Beckmannia syzigachne)、泽珍珠菜(Lysimachia candida)、茴茴蒜(Ranunculus chinensis)、齿果酸模(Rumex dentatus)、蛇床(Cnidium monnieri)、鳢肠(Eclipta prostrata)和看麦娘(Alopecurus aequalis)等在田间水面漂浮能力较强.漂浮期间杂草种子除多集中于田埂附近,也附着于稻稞周围,并有互相结联的趋势.从整体上看,杂草种子漂浮2天后骤降,8天后基本全部沉降.显然,稻田生境的杂草种子大多可以漂浮于水面传播扩散.因此在灌水早期采取过滤或清除水上漂浮杂草种子可以减少杂草种子的输入和加速杂草种子从田间输出,减少杂草发生基数.  相似文献   

12.
Growth of Aspergillus flavus and Trichoderma viride on agar media was inhibited around embryos of green peanut seeds but not around embryos of cured seeds, intact peanut seeds, or testae. Both fungi were able to colonize intact seeds and testae. Substances inhibitory to A. flavus and T. viride were extracted with acetone from cotyledons of freshly harvested peanut seeds. Four compounds inhibitory to A. flavus were detected in crude acetone extracts. Three of the compounds demonstrated properties of phenolics. Results of this study suggest that inhibitory compounds in peanut cotyledons may play a role in protecting the peanut embryo from fungal infection.Journal Series No. 486, New Mexico State University, Agriculture Experiment Station, Las Cruces. This research was supported in part by ARS, USDA Grant No. 12-14-100-9899(34) Crop Research Division, Beltsville, Maryland.  相似文献   

13.
Abstract

The content and composition of lipids and fatty acids of taproots and lateral roots of Vicia faba were investigated with plants grown under saline (80 mM NaCl) and non-saline conditions. Lipids of both types of faba bean roots are constituted of ~80% phospholipids, of ~15% glycolipids and of some 5% of wax-esters. Phosphatidylethanolamine (PE) and phosphatidylcholine are the main constituents of both root types. Di-phosphatyidylglycerol and phosphatidylinositol are present in medium concentrations, whereas phosphatidylglycerol and phosphatidylserine are present only in trace amounts. The content of sulpholipids was much lower in salt-treated roots as compared with that of the controls. The content of cardiolipins and PE was higher in lateral roots than in the taproots. Roots of salt-treated plants had some 18% lower ether-soluble lipid content in the lateral roots, and approximately 28% lower than the taproots. Less than 25% of the fatty acids of the extracted phospholipids were saturated, with palmitic acid as the main constituent (13 – 18%). Linoleic acid comprised 65 – 70% of the unsaturated acids. Differences in the composition of some fatty acids were found between taproots and lateral roots of salt-treated plants. The observed differences in composition between root types suggests that the reported physiological differences between such roots could be based, at least in part, on structural or compositional differences in their lipids.  相似文献   

14.
新建果园几种作物间种模式生态系统结构及功能研究   总被引:3,自引:2,他引:1  
从荒坡地新建果园10多种农作物间种模式中筛选出5种优化模式,分析和评价了各种种植模式的生态系统的结构和功能.结果表明,随着重复种植的增加,5种间种模式土壤有机质年增加5%一20%,全氮年增加7%一40%,全磷年增加8%一70%,全钾年增加15%一80%;水土保持最好的是花生-秋大豆、春大豆-秋大豆,其次为西红柿-白菜、辣椒-西红柿和早稻-红萝卜,土壤平均侵蚀量和地表径流量与对照相比分别降低44.19%、38.24%、39.52%、37.56%、37.30%和22.40%、9.28%、24.11%、21.60%、15.93%;在5种模式中,生物量最高的是辣椒—西红柿,年均达到100276kg.hm^-2,其次是花生-秋大豆,年均达到77026kg.hm^-2;而生产力最高的是花生—秋大豆,达到15619kg.hm^-2,其次是西红柿—白菜,为15394kg.hm^-2;投能效率最高的是辣椒—西红柿,年均达到3.06,其次为西红柿—白菜、花生—秋大豆、春大豆—秋大豆、早稻-红萝卜,分别为2.16、2.15、2.06和0.71.同时,有机、无机能输入效应表明,以生物能为主源输入进行转化利用太阳光能和水土资源,维护了果园生态系统的能量盈余,生态效益较高.  相似文献   

15.
The Food and Agriculture Organization of the United Nations estimates that 25% of the food crops in the world are contaminated with aflatoxins. That represents 100 million tons of food being destroyed or diverted to non-human consumption each year. Aflatoxins are powerful carcinogens normally accumulated by the fungi Aspergillus flavus and A. parasiticus in cereals, nuts, root crops and other agricultural products. Silencing of five aflatoxin-synthesis genes by RNA interference (RNAi) in peanut plants was used to control aflatoxin accumulation following inoculation with A. flavus. Previously, no method existed to analyze the effectiveness of RNAi in individual peanut transgenic events, as these usually produce few seeds, and traditional methods of large field experiments under aflatoxin-conducive conditions were not an option. In the field, the probability of finding naturally contaminated seeds is often 1/100 to 1/1,000. In addition, aflatoxin contamination is not uniformly distributed. Our method uses few seeds per transgenic event, with small pieces processed for real-time PCR (RT-PCR) or small RNA sequencing, and for analysis of aflatoxin accumulation by ultra-performance liquid chromatography (UPLC). RNAi-expressing peanut lines 288-72 and 288-74, showed up to 100% reduction (p≤0.01) in aflatoxin B1 and B2 compared to the control that accumulated up to 14,000 ng.g-1 of aflatoxin B1 when inoculated with aflatoxigenic A. flavus. As reference, the maximum total of aflatoxins allowable for human consumption in the United States is 20 ng.g-1. This protocol describes the application of RNAi-mediated control of aflatoxins in transgenic peanut seeds and methods for its evaluation. We believe that its application in breeding of peanut and other crops will bring rapid advancement in this important area of science, medicine and human nutrition, and will significantly contribute to the international effort to control aflatoxins, and potentially other mycotoxins in major food crops.  相似文献   

16.
Soil is a reservoir for Aspergillus flavus and A. parasiticus, fungi that commonly colonize peanut seeds and produce carcinogenic aflatoxins. Densities of these fungi in soil vary greatly among fields and may influence the severity of peanut infection. This study examined the relationship between soil density of Aspergillus species and the incidence of peanut seed colonization under laboratory conditions. Viable peanut seeds were wounded and inoculated with 20 soils differing in composition and density of Aspergillus species and were then incubated for 14 days at 37 degrees C (seed water activity = 0.92). The effect of soil density of individual section Flavi species (A. flavus strains L and S, A. parasiticus, A. caelatus, and A. tamarii), section Nigri, and A. terreus on the incidence of seed colonization was best expressed as a function of exponential rise to maximum. Exponential curves often rose to maximum percentages of seed colonization by section Flavi species that were well below 100% despite high species densities in some soils. Competition primarily among section Flavi species may explain the reduced incidences of seed colonization. An average of two or fewer propagules of each Aspergillus species in the soil at the wound site was required for colonization of 20% of peanut seeds. Other fungal species were capable of invading peanut seeds only when soil densities of sections Flavi and Nigri species were low.  相似文献   

17.
无公害水稻生产的病虫草调控技术及其效应的研究   总被引:6,自引:6,他引:6  
利用无公害农药和农业措施防治水稻主要病虫草试验结果表明,井·腊芽、井冈霉素和多抗霉素在水稻分蘖末期和孕穗末期各喷施1次,对纹枯病防效达75.16%~94.27%,优于化学杀菌剂三唑酮;春雷霉素和灭瘟素在叶瘟病发生初期及破肚期、齐穗期各喷施1次,对叶瘟防效为50.54%~72.67%,穗瘟为76.66%~8742%,与化学杀菌剂三环唑相当3种无公害农药在二化螟和稻纵卷叶螟1~2龄幼虫期使用,苏云金杆菌防效优于化学杀虫剂杀虫双,皂素·烟碱和苦参碱与杀虫双相当;皂素·烟碱和苦参碱在稻飞虱1~2龄若虫期使用,药后3~30d防效均在70%以上,低于化学杀虫剂吡虫啉,在水稻移栽前耕地2次,再配合施用适量的未腐熟有机质或人工除草,能控制杂草发生和提高产量,采用无公害农药和农业措施防治水稻病虫草,产量较常规化防区略有增加,稻谷中农药残留量较化防区低,符合绿色食品卫生指标要求。  相似文献   

18.
We developed and validated a treatment to inactivate Escherichia coli O157:H7 on radish seeds without decreasing seed viability. Treatments with aqueous ClO(2) followed by drying and dry-heat treatments were evaluated for efficacy to inactivate the pathogen. Conditions to dry radish seeds after treatment with water (control) or ClO(2) were established. When treated seeds with high water activity (a(w)) (>0.99) were stored at 45°C and 23% relative humidity (RH), the a(w) decreased to <0.30 within 24 h. Drying high-a(w) seeds before exposing them to dry-heat treatment (≥60°C) was essential to preserve seed viability. The germination rate of radish seeds which had been immersed in water for 5 min, dried at 45°C and 23% RH for 24 h, and heated at 70°C for 48 h or at 80°C for 24 h was not significantly decreased (P ≤ 0.05) compared to that of untreated radish seeds. Sequential treatments with ClO(2) (500 μg/ml, 5 min), drying (45°C, 23% RH, 24 h), and dry heating (70°C, 23% RH, 48 h) eliminated E. coli O157:H7 (5.9 log CFU/g) on radish seeds and, consequently, sprouts produced from them without decreasing the germination rate. These sequential treatments are recommended for application to radish seeds intended for sprout production.  相似文献   

19.
【背景】利用微生物促进植物健康生长是农业可持续发展的重要方向之一,而种子相关的促生菌可在植物生命周期早期与植物相互作用,对植物健康生长具有重要意义。【目的】发掘与利用种子相关促生菌的前提是筛选获得促生菌菌种资源,验证其益生能力,为其进一步应用与机理研究提供依据与支持。【方法】以花生种子为研究对象,从种子表面及种子内部分离纯化多株菌,测定菌株的固氮、解磷、解钾、吲哚乙酸合成和铁载体合成等促生能力,并验证菌株对常见植物病原菌的生长抑制特性;通过16S rRNA基因序列进行系统发育分析,确定分类地位;通过生物膜形成能力及根际定殖能力测定菌株在植物根际的生存能力;最后通过催芽及盆栽试验测定菌株对花生种子发芽及幼苗生长的影响。【结果】从花生种子表面、种子内和胚根内分离筛选到41株菌,均有吲哚乙酸合成能力,其中35株有固氮能力,2株有铁载体分泌能力,14株有植物病原菌生长抑制能力。各选一株为代表的菌株,即PS3、PE5和PR5,经16S rRNA基因序列比对分析鉴定为芽孢杆菌属(Bacillus)。PS3、PE5和PR5均可在MSgg液体培养基表面形成褶皱较强的生物膜,也可在花生根际形成有效定殖。催芽试验结果表明经过促生菌浸种后花生种子萌发率明显提高,在第2天时,PS5将发芽率由14.17%提高至38.33%,PE5发芽率提高至30.83%,PR5发芽率提高至39.17%。三株菌能够明显促进花生幼苗生长,PS5对花生幼苗苗高、根长、鲜重和干重分别提高21.82%、22.20%、37.11%和35.64%,PE5分别提高17.45%、18.93%、26.10%和21.18%,PR5分别提高23.11%、23.92%、38.66%和37.47%。【结论】筛选获得的花生种子相关促生菌,具有促进植物生长的潜力,明显促进种子萌发及幼苗生长,是良好的促生菌生物资源,具有较好的应用潜力。  相似文献   

20.
几种化学农药对稻田优势种蜘蛛杀伤力的研究   总被引:2,自引:0,他引:2  
胡自强  王洪全 《蛛形学报》2000,9(2):112-115
用5种化学农药对稻田优势种蜘蛛杀伤力的盆栽与田间进行测试。结果表明,5种化学农药对稻田4种优势种蜘蛛都有较大的杀伤力,总的杀伤率达62.1%-91.7%,盆栽施药比田间施药对蜘蛛的杀伤力大。田间试验结果应当比较符合实际;田间试验对照组蛛虫减退的民政部进一步说明,蜘蛛对目标害虫具有良好的控制作用,在晚稻后期,如果蛛虫比在1:5以下,用不着使用化学农药防治。  相似文献   

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