9种杀螨剂对朱砂叶螨不同发育阶段的室内毒力测定

室内采用FAO推荐的玻片浸渍法和叶碟法分别测定了9种杀螨剂对朱砂叶螨雌成螨和卵的毒力。结果表明,杀螨活性最高的是阿维菌素,其次是溴虫腈,卡死克、噻螨酮、哒螨灵、三唑锡也具有较好的杀螨效果,炔螨特的杀螨效果较差,甲氰菊酯和氧化乐果的杀螨效果最差;阿维菌素对朱砂叶螨卵的毒力最高,毒力次之的是噻螨酮、哒螨灵、溴虫腈、三唑锡和卡死克,甲氰菊酯、炔螨特和氧化乐果对卵的毒力最差。另外,对朱砂叶螨雌成螨和卵毒力相差最大的是噻螨酮和哒螨灵,毒力分别相差150.27和134.28倍;其次为三唑锡,相差69.80倍;溴虫腈、卡死克、阿维菌素、氧化乐果、甲氰菊酯、炔螨特对卵和雌成螨的毒力差别相对较小。     

噻虫胺与高效氯氟氰菊酯等混用对黄曲条跳甲增效作用明显

<正>山东农业大学植物保护学院研究人员近期采用浸叶法,测定了噻虫胺、高效氯氟氰菊酯、丁虫腈(丁烯氟虫腈)等7种药剂及其混用对黄曲条跳甲的毒力及增效作用。结果显示:7种药剂中以噻虫胺对黄曲条跳甲的毒力最高,LC50值为315.1mg/L,其毒力倍数是呋虫胺的3.23倍;其次为噻虫嗪和高效氯氟氰菊酯,LC50值分别为473.1和543.1mg/L。     

乙基多杀菌素防治棕榈蓟马效果好

<正>为筛选出用于防治棕榈蓟马的有效药剂,北京市植保科技人员近期采用玻璃残留处理法测定了5种药剂对蔬菜上棕榈蓟马的室内毒力,并进行了田间药效试验。室内毒力测定结果表明,杀虫活性最高的是乙基多杀菌素,其48小时的LC50值为0.19mg/L;其次是阿维菌素、溴氰虫酰胺和啶虫脒,LC50为54.45~76.48mg/L,呋虫胺的毒力最低。田间试验结果表明,6%乙基多     

虫螨磷等四种杀虫剂对粉尘螨的毒力

在25℃实验室条件下,测定了四种杀虫剂对粉尘螨的毒力。马拉硫磷,甲基毒死蜱,溴氰菊酯和虫螨磷的 Lc50值分别是0.100,0.0372、0.0126和0.0089(%).     

乙基多杀菌素防治棕榈蓟马效果好

<正>为筛选出用于防治棕榈蓟马的有效药剂,北京市植保科技人员近期采用玻璃残留处理法测定了5种药剂对蔬菜上棕榈蓟马的室内毒力,并进行了田间药效试验。室内毒力测定结果表明,杀虫活性最高的是乙基多杀菌素,其48小时的LC50值为0.19mg/L;其次是阿维菌素、溴氰虫酰胺和啶虫脒,LC50为54.45~76.48mg/L,呋虫胺的毒力最低。田间试验结果表明,6%乙基多杀菌素悬浮剂和     

叶喷和土施防治柑橘木虱适用药剂不同

正华中农业大学植物科技学院等单位研究人员采用室内药膜法和田间生物测定,评价了12种化学药剂对柑橘木虱成虫的毒力和防治效果,筛选出适合叶面喷雾和土壤淋施的高效低毒化学农药及其最佳使用浓度,为柑橘木虱化学防治的科学精准用药提供参考,并为柑橘黄龙病的综合防控提供理论依据。室内毒力测定结果表明,对柑橘木虱成虫毒力效果较好的是48%噻虫胺、45%毒死蜱、10%溴氰虫酰胺和20%呋虫胺,LC50值分别为1.42、1.48、1.49、1.60mg/L。田间叶面喷雾生测结果表明,20%呋虫     

阿维菌素、溴氰虫酰胺、氟啶虫胺腈防治瓜蚜效果较好

正为了筛选防治西瓜瓜蚜的有效药剂,北京市植保科技人员用6种药剂进行了室内毒力测定和田间药效试验。室内毒力测定结果表明,1.8%阿维菌素EC对瓜蚜的毒力最高,60 g/L乙基多杀菌素SC毒力最低,48小时LC_(50)分别为0.38mg/L和2225.63mg/L。6种药剂毒力大小依次为阿维菌素溴氰虫酰胺氟啶虫胺腈啶虫脒吡虫啉乙基多杀     

18种杀虫剂对华北大黑鳃金龟和铜绿丽金龟的毒力比较

采用浸渍法,测定了18种杀虫剂对华北大黑鳃金龟和铜绿丽金龟2龄幼虫的室内毒力,并比较了供试杀虫剂对两种试虫的毒力差异。结果表明,氨基甲酸酯类杀虫剂和大多数有机磷杀虫剂对两种金龟子幼虫的毒力差异较小,其它各类杀虫剂对铜绿丽金龟的毒力显著高于对华北大黑鳃金龟的毒力。其中新烟碱类药剂对两种试虫毒力差异最大,如啶虫脒对铜绿丽金龟的毒力高于华北大黑鳃金龟159.61倍,另外,苯基吡唑类杀虫剂氟虫腈对两种试虫毒力也相差了85.73倍。     

3种生物杀虫剂与绿僵菌混用对防治沙葱萤叶甲具有协同增效作用

<正>内蒙古农业大学草地昆虫研究中心科研人员采用点滴法,于室内测定了阿维菌素、茚虫威和鱼藤酮等3种杀虫剂单独使用及与绿僵菌混用对沙葱萤叶甲3龄幼虫的协同致死作用,以期为协调使用化学药剂和生防制剂防治沙葱萤叶甲提供参考。3种杀虫剂单独使用时的毒力测定结果表明,阿维菌素对沙葱萤叶甲3龄幼虫的毒力最强,LD50值为4.80ng/头,其次是茚虫威和鱼藤酮,     

苦参碱对B型烟粉虱卵和成虫的毒力均较高

<正>福建农林大学植物保护学院研究人员近期采用浸叶法,分别测定了苦参碱、阿维菌素、氯氰菊酯、灭多威和吡虫啉等5种杀虫剂对B型烟粉虱不同虫态的毒力。试验结果表明,苦参碱对烟粉虱卵的毒力最高,LC50值为0.802毫克/升,其毒力是吡虫啉的323.8倍;阿维菌素、苦参碱和吡虫啉对烟粉虱1龄和3龄若虫的毒力均较高,但对1龄若虫的毒力高于3龄若虫;阿维菌素和苦参碱对烟粉虱成     

“金花”菌食品安全性毒理学评价

按照食品安全性毒理学评价程序,研究了"金花"菌对大小鼠的毒副作用。结果表明,"金花"菌对小鼠的经口LD50>10 000 mg/(kg.bw),属于实际无毒物;骨髓细胞微核试验和精子畸形试验结果均为阴性;30 d喂养大鼠生长发育良好,血液学指标和血液学生化指标均在正常范围内,而且解剖未见异常症状。     

艾叶精油型粮食防虫剂研制及应用

利用艾叶精油微囊化研制出艾叶精油粮食防虫剂,针对玉米象和杂拟谷盗进行防治。艾叶精油粮食防虫剂以艾叶精油和甘油为芯材,以多孔淀粉和β-环糊精为壁材。通过驱避实验和熏蒸实验得出,驱避级别均达到了Ⅴ级。艾叶精油对玉米象的杀虫效果24 h后达到LD50为0.024μL/cm3,对杂拟谷盗的致死率比对玉米象的致死率稍差一点,但也达到了72 h后LD50为0.030μL/cm3。这种新型防虫剂对玉米象和杂拟谷盗的防治过程中,有一个致死率稳定的阶段,是微囊化精油释放的过程,起到了延长杀虫时间的作用。     

不同类型玉米品种饲用营养价值比较

对粮饲兼用玉米鲁单50(LD50)、高油玉米高油115(HO115)和青饲玉米科多4号(KD4)进行比较研究表明: KD4的鲜、干物质产量最高,较LD50高100%、72.2%,粗蛋白和粗纤维的产量也最高,较LD50高80%、149%;HO115的粗脂肪产量最高,较LD50高62%,粗蛋白的产量也较高;LD50的籽粒产量显著高于KD4,但粗蛋白、粗脂肪和粗纤维的产量都最低.不同     

茶黄素提取物及茶黄素片的急性毒性

以茶黄素提取物及终端产品茶黄素片为原料,采用急性毒性试验方法,研究试验小鼠对茶黄素提取物和茶黄素片的急性毒理特性。结果表明,茶黄素提取物对雌性小鼠的急性经口LD50为2710.0 mg/kg体重,是成人日用量的(10~20 mg/kg)的136~271倍;对雄性小鼠LD50为3160.0 mg/kg体重,是成人日用量的(10~20 mg/kg)的158~316倍。茶黄素片对雌性小鼠的急性经口LD50为20000.0 mg/kg体重,是成人日用量的(40~50 mg/kg)的400~500倍;对雄性小鼠的急性经口LD50为14700.0 mg/kg体重,是成人日用量的(40~50 mg/kg)的294~368倍。茶黄素提取物和茶黄素片对雄性小鼠和雌性小鼠的急性经口LD50,均大于成人日用量的100倍,说明茶黄素提取物和茶黄素片的毒性较小,符合保健食品的急性毒性评价标准。     

Evaluation of yield stability of cowpea under sole and intercrop management in Nigeria

Summary Nine cowpea (Vigna unguiculata (L.) Walp.) breeding lines were grown in 13 experiments under sole crop and intercrop management, with and without insecticide application, in Nigeria. Cowpea was intercropped with cassava (Manihot esculenta Cranz), maize (Zea mays L.) and maize-cassava in the forest zone and with sorghum (Sorghum bicolor Moench.) and millet (Pennisetum glaucum (L.) R.Br.) in the savanna zone. Line by cropping system interactions were significant in 5 of 13 experiments and line by insecticide treatment interactions were significant in 2 of 13 experiments. Cowpea yield was severely depressed in intercropped plots and in plots to which no insecticide was applied. Among-environment variation in cowpea yield was greater when no insecticide was applied. Within each management treatment, the yield performance and stability of the cowpea lines was examined. Stability was assessed both by examining among-environment coefficients of variation and by regression analysis. Several of the breeding lines evaluated appeared promising under different levels of management and in a diversity of environments.     

Discussion on the Hydraulic Calculation Method of Loop Heating Pipe Network

The authors definitely make out the concept of loop main pipeline, supplying main pipeline and ramiform branch line, as well as the order of their hydraulic calculation. Then they puts forward the principia of how to study out the direction of loop main pipeline and presents the method of making flux initial distribution. The matrix of loop main pipeline hydraulic square dispersion is set up. The node referenced pressure is defined and the equation of how to calculate it is deduced. A software is developed to calculate the loop main pipeline hydraulic square dispersion. The method of calculating ramiform branch margin impetus is given.     

江西省境内中华秋沙鸭越冬生境选择

为探讨中华秋沙鸭越冬的生境选择策略。2009-2011年12月中旬利用样方法、因子测定法和卡方检验等方法对江西省境内中华秋沙鸭越冬的生境选择进行了调查分析。结果表明：中华秋沙鸭越冬嬉戏、觅食和栖息的生境选择具有普遍性并具有以下特征：越冬地海拔较低,年平均气温为16.5℃;越冬地依山傍水且均沿河流分布,多集中在河流的中下游水势相对平缓地带;越冬生境选择通过植被、水环境和人为干扰因子来实现;对低海拔(50~60 m,78.6%)、低坡度(<0.36,98.6%)、低噪音(<40 dB,89.2%)、村镇(6~12 km,71.9%)、公路中等距离(1~2 km,79.4%)、近林缘(<50 m,85.4%)的区域选择性较高。     

Effect of gamma and ultraviolet irradiation on adventitious regeneration from in vitro cultured pear leaves

Summary Irradiation of in vitro explants and subsequent adventitious regeneration has been tested for 4 commercially important varieties of pear (Pyrus communis) with the aim to create mutants with a reduced susceptibility to fire-blight (Erwinia amylovora). The effect of gamma and ultraviolet irradiation of leaves on adventitious regeneration ability has been studied. The LD50 (50% decrease of regeneration) after gamma irradiation was genotype-dependent and was between 20 and 50 grays. The curves of regeneration showed a threshold dose underneath which none or a very slight decrease was registered. The decrease might result from cumulative events. After an ultraviolet irradiation as low as 62.5 J/m², the leaves became crumbly and rolled up, and their metabolism seemed to be altered. The LD50 was about 125 J/m² for all varieties and the decrease of regeneration was linear. Histological investigations showed leaves with flattened epidermal cells after ultraviolet irradiation and slack spongy parenchyma after gamma irradiation.Abbreviations Gy grays - J joules - LD lethal dose     

草鱼肝胆综合症并发细菌疾病病原分离鉴定及药敏试验

对2016年6月江西省鄱阳县高家岭一个养殖场养殖草鱼发生的暴发性疾病进行病原分离鉴定及药敏试验,旨在确定其病因,为今后生产中有效防控该疾病提供参考。利用细菌分离方法在无菌条件下从患肝胆综合症草鱼体内分离、纯化致病菌,通过形态学、生化鉴定和16SrDNA序列分析、gyrB基因序列分析进行菌株鉴定,用攻毒试验找出草鱼的半致死浓度,并采用滤纸片扩散法进行药敏试验。从患肝胆综合症草鱼体内分离、纯化到一株致病菌,经鉴定为维氏气单胞菌,命名为PYG1。攻毒试验表明该菌能感染草鱼,且半致死浓度为1.5×10 ⁴ CFU/g鱼体质量。药敏试验结果表明该菌只对氨基糖苷类、第二代和第三代头孢类以及喹诺酮类的氧氟沙星共9种药物表现出敏感或中度敏感,对所测的其他药物耐药,为强耐药菌株。维氏气单胞菌PYG1是引起此次草鱼发病的致病菌,可选用氨基糖苷类、头孢类及喹诺酮类的氧氟沙星等药物进行防治。     

Effect of insecticide-tolerant and plant growth-promoting Mesorhizobium on the performance of chickpea grown in insecticide stressed alluvial soils

An experiment was carried out to determine the plant growth-promoting activities of fipronil- and pyriproxyfen-tolerant Mesorhizobium isolates in the presence and absence of insecticides. The bioremediation and plant growth-promoting potentials of Mesorhizobium isolate (MRC4) was assessed using chickpea as a test crop grown under fipronil- and pyriproxyfen-stressed soils. In this study, the most promising mesorhizobial isolate (MRC4) tolerated fipronil and pyriproxyfen up to a concentration of 1600 μg ml^?1 and 1400 μg ml^?1, respectively. Isolate MRC4 produced a substantial amount of indole acetic acid (44.3 μg ml^?1), salicylic acid (35 μg ml^?1), 2,3 di-hydroxybenzoic acid (19 μg ml^?1), and exo-polysaccharides (21 μg ml^?1) in the absence of insecticides. The plant growth-promoting substances displayed by the isolate MRC4 declined progressively with increasing concentrations of each insecticide. The insecticide tolerant isolate MRC4 was further tested for its effect on chickpea plants grown in fipronil- and pyriproxyfen-treated soils. The insecticide-tolerant isolate MRC4 increased the dry matter accumulation progressively. A maximum increase of 80 (at 600 μg kg^?1 soil of fipronil) and 118% (at 3900 μg kg^?1 soil of pyriproxyfen) was recorded 135 days after sowing when compared to noninoculated plants treated with the same rates of each insecticide. Moreover, Mesorhizobium isolate MRC4 when used in fipronil- and pyriproxyfen-treated soil also increased symbiotic properties (nodulation and leghaemoglobin content), root N, shoot N, root P, shoot P, seed yield, and seed protein compared to the un-inoculated but treated solely with insecticide. The present finding suggests that the mesorhizobial isolate endowed with multiple properties could be used to facilitate the productivity of chickpea under insecticidestressed soils.