几种除草剂对大豆孢囊线虫存活和孵化的影响

在实验室内寄主体外测定了8种大豆田常用除草剂对大豆孢囊线虫（SCN）(Heterodera glycines Ichinohe)2龄幼虫（J2）存活率及卵孵化的影响,同时测定了乙草胺和2,4滴丁酯+异丙草胺对温室和田间SCN繁殖的影响。结果表明,所有供试除草剂对大豆孢囊线虫J2均有不同程度的致死作用,其中以乙草胺、2,4滴丁酯+异丙草胺和嗪草酸甲酯处理效果最好,24 h死亡率分别达99.33%、99.33%和89.33%;乙草胺、2,4滴丁酯+异丙草胺、嗪草酸甲酯和精噁唑禾草灵处理7 d,J2的死亡率均达100%,精喹禾灵、精吡氟氯禾草灵和三氟羧草醚处理的死亡率分别为91.33%、81.33%和79.33%;所有除草剂对孢囊孵化都有较强的抑制作用,其中2,4滴丁酯+异丙草胺的抑制作用最强,孢囊孵化率仅为1.25%;乙草胺和2,4滴丁酯+异丙草胺对温室和田间SCN的繁殖均有较强的抑制作用,对大豆根系生长均无不良影响。不同除草剂对大豆种子萌发有一定影响。     

除草剂对星豹蛛活动行为的影响

为明确除草剂对星豹蛛Pardosa astrigera活动行为的影响,采用药膜法测定乙氧氟草醚、乙羧氟草醚和百草枯3种常规除草剂对星豹蛛的毒力,应用旷野试验法研究除草剂对其活动行为的影响。结果表明:乙羧氟草醚对星豹蛛的LC10为6.75 g/L,乙氧氟草醚的LC10为1.09 g/L,3种除草剂对星豹蛛的毒力顺序为乙氧氟草醚乙羧氟草醚百草枯。高浓度(5.81~10.53 g/L)乙氧氟草醚处理后雄蛛的行走总路程和平均行走速度均较推荐浓度处理(0.07 g/L)显著降低,6.75 g/L乙羧氟草醚处理后雌蛛行走总路程较其余浓度处理显著降低、雄蛛最大行走速度较0.08 g/L浓度处理显著降低,但这2种除草剂各浓度处理均与对照无显著差异;80.00 g/L百草枯处理后雄蛛的行走总路程、最大行走速度和平均行走速度均较对照显著降低,分别为248.48 cm、12.03 cm/s和0.83 cm/s,4.00~20.00 g/L百草枯处理后雌蛛最大行走速度较80.00 g/L处理显著下降。5.81 g/L乙氧氟草醚处理后雄蛛行走区域数显著下降,较对照下降了4.57个,而雌蛛行走区域数则显著升高,较对照增加了2.20个。20.83 g/L乙羧氟草醚处理后雄蛛在中心区域停留时间最短,为0.48 s,占总时间的比例仅为0.16%,5.81 g/L乙氧氟草醚处理后雌蛛在中心区域停留时间最长,为15.94 s,占总时间的比例为5.31%。表明高浓度除草剂处理星豹蛛后对其活动行为影响显著,而推荐浓度处理后对其无显著影响,说明3种除草剂在推荐剂量下对星豹蛛相对安全。     

覆膜西瓜田除草剂选择与应用

西瓜在山东省邹平县常年种植近1万hm2,且多为地膜覆盖加小拱棚保护性栽培。覆膜后人工除草困难,只有在覆膜前喷施除草剂,才能使西瓜苗免受草害。西瓜对除草剂特别敏感,以前使用48%甲草胺EC和5%乙草胺EC均出现过不同程度的药害。从2001年开始,我们连续几年在覆膜西瓜田试验了不同除草剂,其结果为72%异丙甲草胺EC60～80m l/667m2、36%萘丙酰草胺·乙氧氟草醚EC(商品名称瓜大壮)120～150m l/667m2、48%双丁乐灵EC(商品名称地乐胺)120～150m l/667m2、24%乙氧氟草醚EC(商品名称果尔)50～60m l/667m2、96%精异丙甲草胺EC(商品名称金都尔)30…     

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...     

几种除草剂组合对蒜田杂草的防除效果

为明确不同除草剂对蒜田杂草防除效果和对大蒜的安全性影响,进行了禾本科杂草与阔叶杂草混生的常规草相蒜田和阔叶杂草占据优势种群的蒜田除草剂防效试验,结果表明：对于常规草相蒜田,以综合防治禾本科杂草和阔叶杂草为目的,可以选择7％草酮·16％乙草胺·12％乙氧氟草醚复配剂或30％二甲戊乐灵·10％乙草胺·4％乙氧氟草醚复配剂;对于以荠菜为优势杂草种群的蒜田,可选择24％乙氧氟草醚;对于以猪殃殃及其他阔叶杂草为优势种群的蒜田,可选择12％草酮。     

乙氧氟草醚防除地膜棉田杂草试验初报

随着地膜棉栽培技术的广泛应用 ,棉田杂草的发生期相应提前 ,加之长期使用氟乐灵进行土壤封闭处理 ,棉田草相发生变化 ,禾本科杂草种类和数量下降 ,阔叶草密度增加 ,上升为优势杂草 ,严重影响地膜棉花正常生长。为寻求适宜的除草剂品种与配方 ,2 0 0 0年我们进行了乙氧氟草醚土壤封闭防除地膜棉田杂草试验 ,取得了较好的效果 ,现将试验结果报告如下 :1　材料与方法1 1　供试药剂( 1 ) 50 %乙草胺ＥＣ(大丰农药厂产 ) ;( 2 )2 0 %乙氧氟草醚ＥＣ (响水农药厂产 ) ;( 3)48%氟乐灵ＥＣ(以色列科尔公司产 ,国内加工 )。1 2　防除对象试验棉田…     

两种二苯醚类除草剂对花生苗期生长发育及氮素代谢的影响

在温室条件下,研究三氟羧草醚和乙羧氟草醚对苗期花生生长发育以及氮素代谢的影响.结果表明两种除草荆均明显抑制苗期花生的生长发育,同时抑制苗期花生的氮素代谢过程中关键酶硝酸还原酶和谷氨酰胺合成酶的活性,导致苗期花生植株的全氮含量显著降低.其中三氟羧草醚对花生生长发育的抑制作用较强,在高剂量下,对花生植株鲜重抑制率、干重抑制率分别为32.85%和30.00%;与对照花生的结瘤率(80.00%)相比,三氟羧草醚处理的花生结瘤率为28.60%;叶片叶绿素含量在处理后各时期均低于空白对照.三氟羧草醚和乙羧氟草醚对花生氮素代谢的关键酶硝酸还原酶和谷氨酰胺合成酶活性均有不同程度的抑制作用,影响了花生氮素的正常代谢.花生植株全氮含量分别为1.452%和1.553%,显著低于对照植株全氮含量.     

4种酰胺类除草剂对玉米的安全性及药效

室内外测定了4种酰胺类除草剂对玉米安全性及药效。结果表明 :异丙甲草胺与异丙草胺对玉米安全性最高 ,甲草胺次之 ,乙草胺对玉米苗期有药害。田间测产证明异丙甲草胺与异丙草胺对玉米增产明显 ,而乙草胺同人工除草对比略有减产。田间药效表明乙草胺对杂草防除效果最高     

山东覆膜棉田杂草调查及化学除草剂应用

采用目测法,对山东省主要棉花产区德州、聊城、滨州的春棉种植区进行了杂草种类及群落构成调查。结果表明:棉田主要杂草隶属20科40种,以禾本科和阔叶杂草混生为主,提出了以杂草构成选择除草剂应用于覆膜棉田的防除方法。经田间实际使用调查,除草剂应用应以乙草胺、扑草净、二甲戊灵、氟乐灵、仲丁灵和乙氧氟草醚等药剂混配或混用为主。     

气相色谱-电子捕获检测器同时测定瓜果类蔬菜中15种除草剂残留

采用气相色谱-电子捕获检测器（GC-ECD）法建立了同时测定瓜果类蔬菜中15种除草剂（氟嘧磺隆、草毒死、敌草隆、氯草定、氟乐灵、炔苯酰草胺、乙草胺、甲草胺、异丙甲草胺、吡唑草胺、硝草胺、丁草胺、丙草胺、齅草酮、吡氟酰草胺）残留量的方法。供试番茄、黄瓜、青椒、茄子、西葫芦、马铃薯、芸豆及萝卜8种样品经乙酸乙酯与二氯甲烷混合溶剂提取,Florisil PR固相萃取柱净化,DM-1毛细管气相色谱柱（30 m×0.32 mm,0.25 μm）分离,GC-ECD测定,外标法定量。结果表明:在0.002~0.5 mg/kg的3个添加水平下,15种除草剂在8种蔬菜中的平均添加回收率为77%~113%,相对标准偏差（RSD）为3.5%~10.8%,定量限为0.001~0.1 mg/kg。采用所建立的方法对市售蔬菜样品进行测定,结果表明,15种除草剂的残留量均小于最大允许残留限量。该方法简单、快速,灵敏度高,适用于同时测定瓜果类蔬菜样品中15种除草剂的残留量。     

Studies into the action of the diphenyl ether herbicides acifluorfen and oxyfluorfen. Part II: The interaction with photosynthetic electron transport reactions

The effects of acifluorfen and oxyfluorfen on photosynthetic electron transport reactions of pea chloroplasts were compared with those induced by paraquat and monuron. Monuron inhibited electron flow between photosystems I and II, and paraquat acted as an electron acceptor for photosystem I, promoting superoxide formation by illuminated chloroplasts. Neither acifluorfen nor oxyfluorfen at concentrations up to 50 μM affected non-cyclic electron flow or promoted superoxide formation. Both herbicides were shown to repress ferredoxin-dependent NADP⁺ reduction by illuminated chloroplasts. Further experiments showed that, in the presence of ferredoxin-NADP⁺ reductase and chloroplast membranes maintained in the dark, p-nitro diphenyl ether (DPE) herbicides promoted the rate of ferredoxin-dependent oxidation of NADPH, implying that these herbicides can accept electrons from reduced ferredoxin. The interaction between acifluorfen, ferredoxin and chloroplast membranes was examined further by following the effect of this herbicide on the peroxidation of illuminated thylakoids. Lipid peroxidation was promoted by acifluorfen, although this effect was abolished if thylakoids were washed prior to use. The effect of washing could be reversed by adding exogenous ferredoxin. These data demonstrate that interaction of DPE herbicides with photosynthetic electron transport in the vicinity of ferredoxin is necessary for light-dependent herbicide activation.     

乙烯利对草甘磷在空心莲子草中传导及生物活性的影响

在人工气候室培养空心莲子草,植株经草甘膦与乙烯利混合处理后,测定对植株的抑制作用和草甘膦的吸收与传导量。结果表明,加入乙烯利(100mg·L~(-1))后草甘膦(300mg·L~(-1))对地下根茎抑制率比对照提高了13.6个百分点。植株经乙烯利喷雾处理后,基芽、地下茎和根系中~(14)C-草甘膦含量分别是对照的3.56、1.75和2.35倍。放射性成像图显示,植株地下茎与根系中~(14)C-草甘膦传导量明显高于对照。     

Baseline sensitivity of natural populations and resistance of mutants of Xanthomonas oryzae pv. oryzae to a novel bactericide,zinc thiazole

During 2009–2010, a total of 323 isolates of Xanthomonas oryzae pv. oryzae were obtained from rice with symptoms of bacterial leaf blight (BLB) in four provinces (Zhejiang, Jiangsu, Anhui and Hubei) in China. These isolates were tested for baseline sensitivity to zinc thiazole, a novel bactericide with strong antibacterial activity against Xanthomonas. The sampled pathogenic population had similar sensitivity to zinc thiazole (0·1–16·8 mg L^?1) in all four regions and over the whole two‐year study period. The baseline sensitivity was distributed as a unimodal curve with a mean EC₅₀ value of 6·79 ± 1·61 mg L^?1. The risk of mutation to resistance of zinc thiazole in X. oryzae pv. oryzae was further evaluated in vitro and in vivo. Twelve zinc thiazole‐resistant mutants were obtained through ultraviolet (UV) irradiation, culturing on zinc thiazole‐amended nutrient agar (NA) plates, and culturing on zinc thiazole‐treated rice plants. These zinc thiazole‐resistant mutants had resistance factors (RF = EC₅₀ value of a mutant / EC₅₀ value of the wildtype parent of this mutant) of 12·4 to 186·1 with a mean RF value of 44·1. Mutants obtained via UV irradiation, culturing on NA plates and culturing on rice plants had mean RF values of 51·8, 24·5 and 14·4, respectively. All mutants showed decreases in resistance to zinc thiazole after 20 successive transfers on bactericide‐free media or 10 successive inoculation–reisolations on bactericide‐free rice plants. No significant difference was found in bacterial growth and sensitivity to bismerthiazol between zinc thiazole‐resistant mutants and their parents. However, a significant decrease was observed in the pathogenicity of zinc thiazole‐resistant mutants compared with their parents, especially for mutants obtained via UV irradiation.     

Polyclonal and monoclonal antibodies for the specific detection of the herbicide acifluorfen and related compounds

Polyclonal and monoclonal antibodies reactive with acifluorfen (AF) were prepared by the immunization of, respectively, rabbits and mice with AF-bovine serum albumin conjugates. The reactivities of polyclonal antibody and three monoclonal antibodies (AF 9-1, AF 51-5 and AF 75-144) were examined in an indirect competitive enzyme-linked immunosorbent assay (C-ELISA). The polyclonal antibody reacted with AF at concentrations of 1·5 to 800 μg litre^-1, while the monoclonal antibodies reacted with AF at concentrations of 3 to 24 μg litre^-1 for AF 9-1, 1·5 to 12 μg litre^-1 for AF 51-5 and 12 to 48 μg litre^-1 for AF 75-144. In the presence of up to 40% methanol in C-ELISA, the monoclonal antibodies, particularly AF 75-144, were less affected in their reactivities with AF than was the polyclonal antibody. Moreover AF 9-1 and AF 51-5 specifically reacted with acifluorfen-methyl and oxyfluorfen, while AF 75-144 reacted with chlornitrofen which did not react with the other antibodies. These results indicated that the antibodies are useful for the assay of AF and its related compounds. © 1997 SCI.     

三种苗前除草剂对茅苍术杂草防治效果及安全性评价

为了筛选出防效好、残留少且对环境影响较小的茅苍术苗前除草剂,选取常用的3种苗前除草剂乙草胺、乙氧氟草醚和二甲戊灵,研究其除草效果,对叶绿素荧光参数的影响,农药残留情况及其对土壤微生物真菌和细菌群落的影响。结果表明,乙草胺的除草效果较好,株防效和鲜重防效都达到了80%以上,对茅苍术叶绿素荧光参数影响较小,农残较少,对土壤细菌和真菌群落无显著性影响;乙氧氟草醚和二甲戊灵对叶绿素荧光参数有影响,短时间内有一定的土壤农残。综合防效和安全性,优选乙草胺作为茅苍术的苗前除草剂。     

咸淡混合水喷灌对土壤水盐运移及小麦、玉米产量的影响

探究不同矿化度咸淡水混合喷灌对冬小麦、夏玉米生长及产量的影响,并通过监测土壤水盐分布状况来选择适宜矿化度的咸淡水灌溉方式。在河北低平原地区开展大田灌溉试验,研究了淡水畦灌、淡水喷灌、2 g·L^-1和3 g·L^-1咸水与淡水混合喷灌对小麦、玉米生长及土壤水盐运移的影响。结果表明：与淡水喷灌相比,连续两年灌溉后,小麦收获时2 g·L^-1和3 g·L^-1矿化度咸淡混合水喷灌处理的根层（0~40 cm）土体含盐量平均分别增加了17.8%和42.7%,0~100 cm土体含盐量平均分别增加了32.9%和74.3%,玉米收获时根层土体含盐量平均分别增加了40.3%和86.9%,0~100 cm土体含盐量平均分别增加了39.0%和88.9%,且3 g·L^-1矿化度咸淡混合水喷灌处理的盐分累积已超出小麦和玉米生长的盐分阈值。2 g·L^-1矿化度处理的冬小麦产量较淡水喷灌处理降低了9.8%~11.4%（差异不显著）,但3 g·L^-1矿化度处理比淡水喷灌处理的产量显著降低了25.0%~25.9%（P<0.05）;2 g·L^-1矿化度处理的夏玉米单株穗粒质量和产量较淡水喷灌处理分别降低了5.1%~10.4%和6.6%~10.5%（差异不显著）,3 g·L^-1矿化度比淡水喷灌处理的百粒重、单株穗粒质量和产量分别降低了18.6%~22.4%、18.2%~25.9%和14.7%~15.3%（P<0.05）,3 g·L^-1矿化度对冬小麦和夏玉米的产量构成因素影响显著。因此,咸淡混合水矿化度不大于2 g·L^-1的喷灌模式用于该地区冬小麦-夏玉米田间灌溉是可行的。     

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。     

Resistance pattern and antioxidant enzyme profiles of protoporphyrinogen oxidase (PROTOX) inhibitor-resistant transgenic rice

We quantified the resistance levels of transgenic rice plants, expressing Myxococcus xanthus protoporphyrinogen oxidase (PROTOX) in chloroplasts and mitochondria, to PROTOX inhibitors, acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon. We also determined whether active oxygen species-scavenging enzymes are involved in the resistance mechanism of transgenic rice. The transgenic rice line M4 was about >200-fold more resistant to oxyfluorfen than the wild-type (WT). M4 was also resistant to acifluorfen, carfentrazone-ethyl, and oxadiazon, but did not show multiple resistance to imazapyr and paraquat, which have different target sites. Acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon reduced the chlorophyll content in leaves of WT, but had minimal or no effect on M4. The PROTOX inhibitors also caused significant lipid peroxidation in the treated leaves of WT rice. However, the malondialdehyde production in M4 was not affected by these herbicides. The WT rice had higher activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase than M4 after treatment with PROTOX inhibitors. A similar response was observed in all cases of antioxidant isozyme profiles analyzed. However, the induction in antioxidant activity in WT was not enough to overcome the toxic effects of a PROTOX inhibitor so the plant eventually died.     

Studies into the action of the diphenyl ether herbicides acifluorfen and oxyfluorfen. Part I: Activation by light and oxygen in leaf tissue

The effect of acifluorfen and oxyfluorfen on chlorophyll bleaching, lipid peroxidation and photosynthesis in pea leaf discs was studied. Both her- bicides induced light-dependent bleaching and lipid peroxidation, the level of damage being greater at higher light intensities. Photosynthetic carbon dioxide fixation was only partially inhibited in treated leaf discs incubated in darkness, thus indicating that these herbicides did not inhibit photo- synthesis as a primary mode of action. Leaf discs maintained in darkness showed no visible signs of injury, and light-dependent herbicide-induced damage was reduced by incubating discs under nitrogen, orpre-incubating them with the electron-transport inhibitor monuron. It is suggested that acifluorfen and oxyfluorfen are activated by a light-dependent process, which requires photosynthetic electron transport.     

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。