乙羧氟草醚对斑马鱼的急性毒性和生物富集性研究

采用半静态法测定了乙羧氟草醚对斑马鱼Brachydanio rerio的急性毒性和生物富集系数。以N,N-二甲基甲酰胺和吐温-80为助剂,配制不同浓度的乙羧氟草醚溶液,测得其对斑马鱼的 LC50值为 3.10 mg/L,属于中等毒性。生物富集性试验中设乙羧氟草醚浓度为0.03 和0.30 mg/L, 持续暴露时间为8 d,测得生物富集系数 (BCF8d)分别为1.16 和2.43,属于低富集性。     

苄嘧磺隆与乙羧氟草醚混用防除稻田杂草初报

苄嘧磺隆与乙羧氟草醚混用对难以防除的稻田莎草科杂草和阔叶杂草,作用迅速,防除效果好,一次施药可有效防除这类杂草。安全有效剂量为10%苄嘧磺隆可湿性粉剂40g 10%乙羧氟草醚乳油10mL/667m2。     

26%氟磺胺草醚乙羧氟草醚水剂防除花生田阔叶杂草田间药效试验

为明确26%氟磺胺草醚.乙羧氟草醚水剂对花生田阔叶杂草的防除效果,掌握最佳使用剂量,对其进行了田间药效试验。结果表明,2 6%氟磺胺草醚.乙羧氟草醚水剂234~273 g/hm2对花生田阔叶杂草有明显的防除效果,茎叶喷雾处理15 d对试验地杂草的株防效可达85.7%~94.2%,30 d平均鲜重防效达86.3%~95.0%。     

乙氧氟草醚的应用前景与使用技术

乙氧氟草醚为美国罗门哈斯公司(现陶氏公司)1975年开发成功的二苯醚类除草剂，其制剂为24％乙氧氟草醚EC，商品名称果尔。先后在美国、巴西、墨西哥等国取得登记，并于20世纪80年代在中国登记，登记作物为水稻，此后又扩大到森林苗圃、甘蔗、大蒜、花生、棉花。目前，该产品国内已有多家企业获得登记。     

乙羧氟草醚水解动态

采用气相色谱仪,建立了水中乙羧氟草醚残留量的分析检测方法,并在室内研究了其在不同温度、不同pH值缓冲溶液中的降解动态。结果表明:乙羧氟草醚在不同温度和不同pH值条件下的降解均符合典型的一级动力学规律。在同一温度下,其水解速率常数随着pH的升高而增大;在同一pH值条件下,温度升高,降解速率加快。在25℃时,乙羧氟草醚在pH值分别为9、7、5的缓冲溶液中的降解半衰期分别为85.6 min、144.4 h和12.2 d;在50℃时,其在相应缓冲溶液中的降解半衰期分别为23.3 min、13.4 h和10.7 d。研究表明乙羧氟草醚为易水解农药。     

二苯醚类除草剂与草甘膦的混用技术

随着免耕技术以及大田定向喷雾等技术在国内的推广,草甘膦、百草枯等灭生型除草剂由于其具有杀草谱广、防效突出的优点在国内得到广泛推广。但是随之而来的问题是：多年连续使用这些除草剂造成草相在人为压力下加速演替过程,致使多种抗性杂草的泛滥。世界十大恶性杂草之一的马齿苋与铁苋菜在连年使用草甘膦的地块已经成为优势草种。而二苯醚类除草剂普遍对马齿苋和铁苋菜都有较好的防治效果,在实践中大家开始摸索着推广草甘膦与乙羧氟草醚的混用技术。而且在实践中有人注意到一个问题,铁苋菜某些亚种使用草甘膦效果很不理想,在铁苋菜较大时单用乙羧氟草醚也难收到较好效果,但是在两者混用时却收到了较理想的防治效果。而且在荆州公安地区有人用乳氟禾草灵与草甘膦混配发现对铁苋菜（当地称”茶叶草”）效果更优。也有人认为草甘膦是内吸传导型除草剂,吸收需要一定时间,而二苯醚类除草剂如乙羧氟草醚、乳氟禾草灵、氟磺胺草醚等都是触杀作用为主的除草剂,光照下迅速起效,破坏和杀死植物组织,不利于草甘膦的吸收和传导,两者混用应当降低了草甘膦的防治效果。与实践经验相悖。我们用药时又应当何去何从呢？     

气相色谱-串联质谱法检测乙氧氟草醚、唑草酮和乙螨唑在4种香辛料中的残留

建立了气相色谱-三重四极杆串联质谱 (GC-MS/MS)检测留兰香、桂皮、薄荷和月桂叶中乙氧氟草醚、唑草酮、乙螨唑残留的分析方法。4种香辛料用超纯水饱和，乙腈提取，无水硫酸镁及氯化钠盐析，氨基/石墨化碳黑 (NH₂-Carb) 固相萃取柱净化，多反应监测模式，气相色谱-串联质谱测定。结果表明:乙氧氟草醚在0.002 5~2 mg/L范围内，唑草酮和乙螨唑在0.01~2 mg/L范围内，3种农药的进样质量浓度与对应的峰面积间呈良好的线性关系，r > 0.99；乙氧氟草醚在0.025、0.5和2 mg/kg 3个添加水平下，在4种香辛料中的平均回收率在86%~112%之间，相对标准偏差 (RSD)在2.4%~9.6%之间；唑草酮在0.2、0.5和2 mg/kg 3个添加水平下的平均回收率在87%~114%之间，RSD在2.4%~11%之间；乙螨唑在0.5、2和5 mg/kg 3个添加水平下的平均回收率在86%~116%之间，RSD在3.2%~11%之间。乙氧氟草醚、唑草酮和乙螨唑在4种香辛料中的定量限 (LOQ) 分别为0.025、0.2和0.5 mg/kg。     

几种除草剂对棉田杂草的防除效果及安全性评价

本文研究了几种除草剂对短季棉杂草的防治效果及安全性评价。结果表明,通过土壤封闭处理,以34%氧氟·甲戊灵300 mL/667m²和960 g/L精异丙甲草胺100 mL/667m²+240 g/L乙氧氟草醚40 mL/667m²对单双子叶杂草的防效最好,但34%氧氟·甲戊灵药害等级为2级,而960 g/L精异丙甲草胺+240 g/L乙氧氟草醚处理药害极轻微,其影响可忽略不计;通过茎叶喷雾处理,以10%精喹禾灵150 mL/667m²+10%乙羧氟草醚30 mL/667m²+30%草甘膦300 mL/667m²和240 g/L烯草酮80 mL/667m²+10%乙羧氟草醚30 mL/667m²+30%草甘膦异丙胺盐300 mL/667m²的除草效果较优且药害较小。在实际生产应用中,可先选择960 g/L精异丙甲草胺100 mL/667m²+240 g/L乙氧氟草醚40 m...     

二甲戊灵和乙氧氟草醚在生姜上的残留分析及土壤中的消解动态

建立了气相色谱-质谱联用（GC-MS）同时测定二甲戊灵和乙氧氟草醚在生姜、茎秆和土壤中残留量的分析方法,并采用该方法研究了两种农药在土壤中的消解动态及在土壤和生姜中的最终残留。样品前处理采用QuEChERS法,经乙腈提取,姜块和茎秆提取液分别用N-丙基乙二胺（PSA）和石墨化碳黑（GCB）净化,土壤提取液用弗罗里硅土柱净化,选择离子监测模式（SIM）扫描,外标峰面积法定量。结果表明:当添加水平为0.01~0.5 mg/kg时,二甲戊灵在生姜、茎秆和土壤中的回收率分别为91%~100%、90%~98%和86%~100%,相对标准偏差（RSD）分别为3.2%~3.7%、2.7%~4.2%和3.2%~5.1%;乙氧氟草醚在生姜、茎秆和土壤中的回收率分别为90%~95%、86%~91%和85%~95%,RSD分别为2.4%~4.4%、3.9%~5.5%和2.3%~4.9%;样品中二甲戊灵和乙氧氟草醚的定量限（LOQ）均为0.01 mg/kg。二甲戊灵在土壤中的消解半衰期在12.5~20.5 d之间,乙氧氟草醚在18.8~25.6 d之间。采用33%二甲戊灵乳油和24%乙氧氟草醚乳油混剂分别按推荐剂量（有效成分693 g/hm2和72 g/hm2）和高剂量（有效成分1 039 g/hm2和108 g/hm2）于种植后施药1次,在生姜收获期的姜块中均未检出二甲戊灵和乙氧氟草醚残留。研究结果可为二甲戊灵和乙氧氟草醚在生姜上的合理使用及其最大允许残留限量（MRL）标准制定提供参考。     

3种除草剂对甘薯田杂草的田间防效试验

为明确乙草胺、乙氧氟草醚、二甲戊乐灵3种除草剂对甘薯的安全性和对甘薯田杂草的防治效果,进行了田间小区试验。结果表明：各处理对甘薯安全,综合30、45d调查结果,喷洒50％乙草胺乳油4500mL／hm^2对禾本科杂草株防效较好;喷洒24％乙氧氟草醚乳油1500mL／hm^2对阔叶杂草防效较好;喷洒50％乙草胺乳油4500mL／hm^2、24％乙氧氟草醚乳油750mL／hm^2和24％乙氧氟草醚乳油1500mL／hm^23个处理对杂草的综合防效较好。30d综合株防效分别为73．05％、65．55％、83．81％;45d综合株防效分别为86．26％、84．54％、88．81％,鲜重防效分别为92．90％、97．11％、97．80％,可有效防除甘薯田杂草。     

防除大豆田铁苋菜的茎叶处理除草剂筛选

铁苋菜（Acalypha australis L.）在黑龙江省大豆田的种群数量及其危害日益严重,农民已将其列为难防杂草。采用盆栽试验方法,筛选了防治铁苋菜的茎叶处理除草剂。结果表明,灭草松、噻吩磺隆、异噁草松、咪唑乙烟酸对2～6叶期铁苋菜无防除效果;防除2叶期铁苋菜,可以施用氟磺胺草醚300 g/hm2、乳氟禾草灵90 g/hm2、乙羧氟草醚60 g/hm2;防除4叶期铁苋菜,氟磺胺草醚施药量需高于300 g/hm2,乙羧氟草醚的施药量需高于90 g/hm2;防除6叶期铁苋菜,仅能施用氟磺胺草醚,且施药量需高于300 g/hm2。     

星豹蛛PaCYP3001U16基因的克隆与表达分析

为探究细胞色素P450基因在星豹蛛Pardosa astrigera体内的表达特性及对溴氰菊酯胁迫的响应,采用反转录PCR技术克隆其细胞色素P450基因并进行序列分析,采用实时荧光定量PCR(quantitative real-time PCR,RT-qPCR)技术分析其在星豹蛛各发育阶段及雌雄成蛛不同部位的表达水平,同时分析其在溴氰菊酯不同浓度胁迫下和不同处理时间后的表达模式。结果显示,在星豹蛛雌成蛛中克隆得到1个细胞色素P450基因,其开放阅读框为1 473 bp,编码490个氨基酸,命名为PaCYP3001U16(GenBank登录号为MZ643213)。PaCYP3001U16基因在星豹蛛各发育阶段均有表达,其中在成蛛期的表达量最高,在6龄幼蛛期的表达量最低;该基因在雌雄成蛛腹部的表达量显著高于在头胸部及足部的表达量。星豹蛛雄成蛛经LC10(5.151 mg/L)、LC30(8.619 mg/L)和LC50(12.311 mg/L)溴氰菊酯处理12 h,PaCYP3001U16基因的表达量均被抑制,且在LC50处理下表达量最低。PaCYP3001U16基因经LC30溴氰菊酯处理...     

Effects of dose and application timing on the seed production of three weed species treated with MCPA or tribenuron-methyl

The seed production of Fallopia convolvulus (L.) A. Love, Galium spurium L, and Thlaspi arvense L., treated with MCPA or tribenuron-methyl, was studied in a pot experiment. The herbicides were applied in doses from 1/16 to 1/l of a full dose at five different growth stages. The largest reduction of seed production was observed on plants treated when one true leaf had developed (F. convolvulus, both herbicides) or at the beginning of the generative phase (G. spurium treated with tribenuron-methyl and T. arvense treated with either herbicide). Tribenuron-methyl (0.375 g a.i. ha^?1) or MCPA (0.1875 kg a.i. ha^?1) applied at bolting stage was enough to reduce the seed production of T. arvense by 83% and 100%, respectively. The seed production of F. convolvulus, treated with 0.75 kg MCPA at the cotyledon stage, was reduced by 70%. Plants of G. spurium with 5–9 axillary shoots, treated with 3 g tribenuron-methyl, produced 45% fewer seeds than the control. Both herbicides (at least at the highest doses) reduced seed production of all three species more than shoot dry matter.     

Photosynthesis and growth responses of grapevine to acetochlor and fluoroglycofen

Acetochlor and fluoroglycofen are herbicides used in vineyards to eradicate weeds. This present study characterized the effects of these chemicals on photosynthetic characteristics and the antioxidant enzyme system in non-target grape leaves. The results showed that acetochlor and fluoroglycofen reduced net photosynthetic rate in a dose-dependent manner, but also reduced or increased pigment contents, respectively. According to chlorophyll fluorescence measurements, acetochlor and fluoroglycofen decreased the photochemical efficiency of photosystem II in the light and increased non-photochemical quenching. These herbicides enhanced malondialdehyde contents and accelerated the superoxide anion production rate in dose-dependent manners, which might be associated with lower antioxidant enzyme activities, especially at higher concentrations of the herbicides. Acetochlor and fluoroglycofen inhibited grapevine growth in the growth season one-year after herbicide treatment, and stem height was inhibited by up to 55.4% and 88.0%, respectively. Taken together, these results suggest that both herbicides are detrimental for grape photosynthesis and this might be associated with increased oxidative stress in the first year, while growth inhibition in the second year might be due to after effects of herbicide treatment.     

Effects of agrochemical residues on four spider taxa: Laboratory methods for pesticide tests with web-building spiders

The susceptibility of web-building and hunting spiders from the tropics (Panama), Europe (F.R. of Germany) and the Middle East (Israel) to 30 pesticides (16 insecticides, 4 acaricides, 1 herbicide, 9 fungicides) was determined. Laboratory test methods for juvenile and adult web-building spiders are described.Philodromus sp. (hunting spider), was completely resistant to all substances;Argiope sp. (web-building spider),Linyphia sp. (web-building spider) andChiracanthium sp. (hunting spider) showed medium to high susceptibility. Insecticides affected spiders in a wide range of responses: from no mortality (most compounds of biological origin) and medium mortality (pyrethrin compounds, organophosphorus and carbamate compounds), to high mortality (cyclo compounds). To both groups of spiders (the hunting and web-building), most acaricides were highly toxic, whereas herbicides and fungicides were nontoxic.     

除草剂对小麦田雀麦的生物活性测定

为筛选防除雀麦Bromus japonicus的高效除草剂,采用室内生物测定法研究了13种除草剂对雀麦的除草活性及5种除草剂的田间药效试验。结果表明,在田间推荐剂量的低剂量下,氟唑磺隆、啶磺草胺、氟噻草胺、甲基二磺隆、异丙隆、磺酰磺隆、丙苯磺隆7种除草剂对雀麦具有很高的防除效果,21 d鲜重抑制率分别为88.30%、86.32%、83.97%、78.47%、76.76%、72.83%、71.39%,高剂量下的21 d鲜重抑制率达98.57%、95.36%、91.58%、91.46%、89.47%、82.48%、82.20%;其中氟唑磺隆各剂量下的防效较其它除草剂高。而嘧啶肟草醚、苯唑草酮、炔草酯、吡氟酰草胺、唑啉草酯、精噁唑禾草灵6种除草剂对雀麦防效较差。氟唑磺隆、啶磺草胺、氟噻草胺、甲基二磺隆、异丙隆5种除草剂的田间药效试验表明,氟唑磺隆对雀麦防效最高,高剂量下20 d株防效达85.04%,药后40 d株防效和鲜重防效分别达83.94%和84.17%,未见小麦有明显药害症状,建议田间推荐用量为21.00~42.00 g(a.i.)/hm~2。表明雀麦对不同除草剂的敏感性存在差异,在供试的13种除草剂中氟唑磺隆对雀麦防效最高,较为安全,为防除雀麦的理想除草剂。     

14种除草剂对野稷的活性测定及田间防效

参照除草剂室内生物测定和田间药效防治试验准则,在温室中测定了14种除草剂对野稷的生物活性,并进行了田间小区药效评价。生测结果表明,土壤处理药剂中,异噁唑草酮、氟噻草胺、乙草胺、精异丙甲草胺、异噁草松对野稷的活性较高,其ED₉₀分别为43.08、47.14、137.09、209.93、583.74 g/hm²(有效成分用量);茎叶处理药剂中,苯唑草酮、高效氟吡甲禾灵、烟嘧磺隆和苯唑氟草酮对野稷的活性较高,其ED₉₀分别为22.21、35.95、95.64、111.43 g/hm²。田间药效试验结果表明,野稷出苗前,土壤喷雾40%氟噻草胺SC (810 g/hm²)、900 g/L乙草胺EC (1 620 g/hm²)和960 g/L精异丙甲草胺EC (2 160 g/hm²)对野稷防效较高,药后40 d对野稷的株防效均在86.0%以上,鲜重防效在88.4%以上,其次是75%异噁唑草酮WG (90 g/hm²),防效...     

几种除草剂对胡麻田裸燕麦(莜麦)、皮燕麦的防除效果

本文开展了唑啉草酯等7种除草剂对胡麻田裸燕麦、皮燕麦的防除试验研究,结果表明,在胡麻株高5~7cm,裸燕麦、皮燕麦3~5叶期施药,50g/L唑啉草酯乳油、108g/L高效氟吡甲禾灵乳油、15%精吡氟禾草灵乳油、240g/L烯草酮乳油和10%精喹禾灵乳油有效成分剂量分别为90、145.8、315、432和90g/hm2时,药后45d对裸燕麦的株防效达95.39%以上,鲜重防效达97.21%以上,胡麻增产率在82.79%以上;50g/L唑啉草酯乳油、108g/L高效氟吡甲禾灵乳油、15%精吡氟禾草灵乳油、15%炔草酯可湿性粉剂、10%精喹禾灵乳油和12.5%烯禾啶乳油有效成分剂量分别为90、145.8、270、135、90和412.5g/hm2时,药后45d对皮燕麦的株防效在94.66%以上,鲜重防效达96.13%以上,胡麻增产率在80.25%以上,各药在上述剂量下防治裸燕麦和皮燕麦后均对胡麻表现安全,可大面积示范推广。     

Effect of pesticides on spiders occurring on apple and citrus in Israel

Field experiments in an apple orchard and in a citrus grove were carried out to evaluate the effect of four commercial pesticides in common use in Israel against apple and citrus pests, on the spider populations inhabiting the trees. The spider populations on apple were markedly suppressed by the pesticides, the order of toxicity being Talstar (biphenate) >Mavrik (fluvalinate) > Smash (fenpropathrin) > Dursban (chlorpyrifos). When grapefruit trees were treated with carbaryl + formothion, 232 spiders were sampled in the unsprayed plot, 55 days after treatment, as compared with only 11 spiders in the treated plot. Two and 7 days after treatment with chlorobenzilate, the sample from the treated plot numbered 68 and 55 spiders, respectively, as compared with 50 spiders collected 24 h before treatment. In addition, laboratory tests were carried out to determine the susceptibility of the spiderChiracanthium mildei L. Koch to 17 pesticides. When the spiders were exposed to grapefruit leaves which had been dipped 1 h previously for 5 sec in the aqueous emulsions of the pesticides, chlorpyrifos, fenpropathrin, fenvalerate, phosphamidon and biphenate caused 100%, and cypermethrin and fluvalinate 60% mortality, whereas all the other pesticides tested - acaricides, fungicides and herbicides - caused about 10-40% mortality.