ALA提高丙酯草醚胁迫下油菜幼苗耐性研究

对油菜幼苗叶面喷施不同浓度的丙酯草醚(ZJ0273)和5-氨基乙酰丙酸(ALA),研究了ALA与丙酯草醚协同处理对苗期的油菜是否安全。结果表明,丙酯草醚随浓度从100~1000mg/L变化,逐渐抑制油菜幼苗生长,鲜重减少,净光合速率和叶绿素含量降低;过氧化物酶(POD)、超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性下降,丙二醛(MDA)积累提高。而10~100mg/L的ALA则促进油菜幼苗生长,增加植株的鲜重、净光合速率并提高了叶绿素含量,POD、SOD和APX酶活性均比对照显著提高,MDA积累减少;500mg/L的ALA效果相反,表现为抑制作物生长。100mg/L ALA和不同浓度的丙酯草醚协同处理,油菜幼苗均比对照生长的更好,鲜重增加,净光合速率提高,抗氧化酶活性增加,MDA积累减少。因此,ALA可以提高油菜幼苗在除草剂丙酯草醚胁迫下的耐性。     

甲氨基阿维菌素苯甲酸盐与杀虫双对斜纹夜蛾毒力最佳配比筛选

[目的]筛选出对斜纹夜蛾具有增效作用的甲氨基阿维菌素与杀虫双最佳配比,为其混剂研发及现场桶混应用提供科学依据.[方法]采用浸叶法测定甲氨基阿维菌素、杀虫双单剂及其混剂对斜纹夜蛾3龄幼虫的毒力,筛选出具有增效作用的最佳配比.[结果]甲氨基阿维菌素:杀虫双为70∶30和60∶40即有效成分质量比为0.14∶243.00和0.12∶324.00时毒效比分别为1.34和1.45,表现出增效作用,其共毒系数分别为125.93和151.08.[结论]甲氨基阿维菌素与杀虫双按有效成分质量比为0.12∶324.00混配时,对斜纹夜蛾幼虫的毒力增效作用最明显,为防治斜纹夜蛾的最佳配比.     

高效液相色谱法测定甲维盐和吡虫啉在番茄及其土壤中的残留量

为建立同时检测番茄及其土壤中甲维盐和吡虫啉残留的快速分析方法,采用丙酮/水（1∶1, V/V）提取样品,经硅胶和活性炭混合物层析柱净化,HPLC-UV 检测,对甲维盐和吡虫啉在番茄及其土壤中的残留进行了检测。结果表明：1）甲维盐和吡虫啉的混合标样添加量为0．05～1．0 mg/kg 时,甲维盐在番茄和土壤中的添加回收率分别为82．54％～86．60％和82．50％～96．21％,相对偏差分别为0．96％～3．30％和0．79％～3．93％;吡虫啉在番茄和土壤中的添加回收率分别为83．25％～94．20％和90．52％～98．39％,相对偏差分别为0．71％～1．78％和0．80％～3．24％,说明该方法的准确度和精密度均符合农药残留分析的要求,适合番茄及其土壤中甲维盐和吡虫啉的残留量检测。2）采用该方法对2013年番茄及其土壤中甲维盐、吡虫啉的残留状况进行检测表明,施药5 d 后的番茄甲维盐残留量为0．03～0．05 mg/kg,吡虫啉残留量为0．05～0．10 mg/kg;施药5 d 后,土壤中甲维盐的残留量为0．03～0．05 mg/kg,吡虫啉的残留量为0．04～0．08 mg/kg。两种农药在番茄和土壤中的残留量均未超过我国在番茄中最高残留限量标准的规定。     

蜈蚣兰初代培养中内生真菌的抑制作用

为了建立蜈蚣兰无菌繁殖体系,以0.2%的山梨酸钾和0.2%的苯甲酸钠为供试药剂,研究了两种不同种类的食品防腐剂在蜈蚣兰初代培养中对内生真菌的抑制作用。结果表明:两种食品防腐剂均对蜈蚣兰内生真菌的生长有抑制作用,且山梨酸钾的抑菌作用更为显著。同时,两种防腐剂的加入对外植体侧芽萌发均有一定程度的抑制,且苯甲酸钠的抑制作用较为突出。另外,0.8%的次氯酸钠溶液对蜈蚣兰内生真菌的生长也有一定的抑制作用。     

甲氨基阿维菌素苯甲酸盐对3种鳞翅目害虫与赤眼蜂的毒力

摘 要：为明确甲氨基阿维菌素苯甲酸盐对甘肃河西地区3种玉米害虫和松毛虫赤眼蜂的毒力,协调甘肃河西地区化学防治和生物防治之间的矛盾,本研究在室内采用饲喂法和药膜法分别对棉铃虫、亚洲玉米螟、粘虫和松毛虫赤眼蜂进行毒力测定。结果表明,随着甲氨基阿维菌素苯甲酸盐浓度增加,4种昆虫的校正死亡率均呈递增趋势,当药剂浓度达0.500 mg/L时,4种昆虫的校正死亡率均达95%以上。致死中浓度表明,甲氨基阿维菌素苯甲酸盐对松毛虫赤眼蜂毒力最高,致死中浓度LC50为0.078 mg/L,其次依次为亚洲玉米螟、棉铃虫和粘虫,致死中浓度LC50依次为0.109、0.120、0.127 mg/L。甲氨基阿维菌素苯甲酸盐对松毛虫赤眼蜂的毒力是其他3种鳞翅目昆虫的1.40~1.63倍。因此,综合防治中使用甲氨基阿维菌素苯甲酸盐防治害虫时,应避开赤眼蜂的出蜂时期,以降低化学杀虫剂对赤眼蜂的杀伤作用。     

Control of insect pests using trunk injection in a newly established apple orchard

We evaluated the potential for using preplant trunk injections of emamectin benzoate in nonbearing apple trees. Trees were evaluated for pest injury and emamectin residues throughout the planting season and into the following year. Injections into the trunk best delivered emamectin benzoate to the canopy compared with injections into the taproot, and the higher rate reduced insect pests more than the lower rate. In the following year, differences in insect control between trunk and root injections were less pronounced, but the higher rate of emamectin benzoate persisted longer and better reduced pests relative to the other treatments.     

Safety and efficacy of emamectin benzoate administered in-feed to Atlantic salmon, Salmo salar L., smolts in freshwater, as a preventative treatment against infestations of sea lice, Lepeophtheirus salmonis (Krøyer)

The safety and efficacy of emamectin benzoate, administered in-feed to Atlantic salmon smolts, Salmo salar L., held in freshwater, was evaluated as a preventative treatment against sea lice, Lepeophtheirus salmonis, following transfer of fish to seawater.

In the safety study, salmon smolts held in freshwater were fed with diets containing emamectin benzoate at nominal doses of 0 (control), 50 (recommended dose) and 250 (5× recommended dose) μg kg⁻¹ fish day⁻¹ for 7 days (days 0–6). Actual dose rates, based on measured concentrations of emamectin benzoate in feed, differences in fish weight, and feed consumed, were 0, 54, and 272 μg kg⁻¹ day⁻¹, respectively. On day 9, fish were transferred to seawater and observed for 14 days. No differences in feeding response, coordination, behaviour, gross and histological appearance were observed between control fish and those that received 54 μg kg⁻¹ day⁻¹. Among smolts that received 272 μg kg⁻¹ day⁻¹, approximately 50% exhibited darker coloration, and one fish (1%) exhibited uncoordinated swimming behaviour. No pathognomonic signs of emamectin benzoate toxicity were identified.

In the efficacy study, smolts held in freshwater were fed an unmedicated ration (control group) or emamectin benzoate at 50 μg kg⁻¹ day⁻¹ (treated group) for 7 days (days 0–6). On day 9, fish were re-distributed to eight seawater tanks, each holding 30 control and 30 treated fish. On days 28, 56, 77 and 109, respectively, control and treated fish in two tanks were challenged with L. salmonis copepodites. When lice in each group reached chalimus stage IV, fish were sampled and the numbers of lice were recorded. Fish challenged at day 109 were sampled for the second time when lice were at the adult stage. Efficacy was calculated as the reduction in the mean number of lice on treated fish relative to the mean on control fish. Treatment with emamectin benzoate resulted in an efficacy of 85.0–99.8% in fish challenged at days 28–77, from the start of treatment, and lice counts were significantly lower (P<0.001) on treated fish than on controls. When fish challenged at day 109 were sampled at day 128, efficacy was 44.3%, but survival of chalimus to adult lice on treated fish was lower, and at day 159, efficacy had increased to 73%. These results demonstrate that treatment of salmon smolts with emamectin benzoate in freshwater was well tolerated and highly effective in preventing sea lice infestation following transfer of fish to seawater.     

Bio-efficacy of denatonium benzoate added formulation of bromadiolone against commensal rodents

Present day rodent management technology mostly relies on use of rodenticides, which is unsafe for human beings and other non-targets. Denatonium benzoate (DB) is an intensely bitter and non-toxic substance which is detectable by humans at a concentration of 10 ppb. Denatonium benzoate added wax block formulation of bromadiolone (0.005%) (an anticoagulant rodenticide) was evaluated against commensal rodents (house rat, Rattus rattus and lesser bandicoot rat, Bandicota bengalensis), which are always found in the proximity of pets, domestic animals and human beings. Single day exposure to bromadiolone (0.005%) formulation with DB and without DB in no-choice tests yielded 100% mortality in both the test rodent species in 2–11 days. The amount of poison bait ingested by R. rattus and B. bengalensis for both the formulations did not differ significantly, ranging between 5.87 - 7.30 and 6.51–6.71 g/100 g body weight, respectively. In choice tests in the presence of alternate plain food (broken wheat grain), consumption of both the formulations of bromadiolone (0.005%) (with and without DB) was similar to plain food at both the exposure periods (1 and 2 days), indicating a good acceptability of test rodenticide. However, mortality with a single day exposure to bromadiolone (0.005%) formulation with DB was 70% and without DB was 60–80% in both test rodent species within 3–14 days. With a two days exposure period, mortality was 100% in both the species of test rodents in 3–13 days. Single day choice test between the formulations revealed that intake of baits of both formulations by both the test rodents was similar i.e., in the range of 8.16–8.94 g/100 g b wt (bromadiolone with DB) and 8.20–9.5 g/100 g b wt (bromadiolone without DB) indicating that incorporation of a bittering agent (DB) with bromadiolone did not alter the consumption of poison in both the test species. In field trials the mean control success as assessed by census baiting and trapping methods with the application of bromadiolone (0.005%) with DB ranged between 54.0% (houses and shops) to 68.4% (poultry farms) and was 55.6% (houses and shops) to 68.4% (poultry farms) in treatments with bromadiolone (0.005%) without DB. It can be concluded that denatonium benzoate could be a best additive in rodenticidal formulations as the acceptability, palatability and toxicity in the laboratory and also its performance in field in managing the pest rodents were not altered.     

Sea lice treatments, management practices and sea lice sampling methods on Atlantic salmon farms in the Bay of Fundy, New Brunswick, Canada

Proper monitoring of all stages of sea lice is imperative to ensure the strategic timing of treatments. Although sea lice receive close attention and management for production purposes, there are no regulations for the reporting of lice burdens on salmon farms in Atlantic Canada, nor are there officially standardized protocols for conducting sea lice counts in the field. The purpose of this study was to complete a survey of Atlantic salmon farms in the Bay of Fundy, NB, Canada. The survey addressed many aspects of sea lice monitoring and control, including methods for sea lice sampling at the site, types of treatments administered for control of sea lice and management practices and decisions regarding the control of sea lice. A total of 83 surveys were completed from July to December 2002. Twelve of the 60 respondents owned and/or operated more than one site and completed a survey for each of their sites at the time of the interview. The position of individuals surveyed included 48 site managers (representing 63 sites), three site owners (representing 11 sites), eight individuals who were both owner and manager (representing nine sites) and one site veterinarian (representing one site). Surveys were completed on 30 sites from the Limekiln Bay and surrounding areas, 23 sites from Grand Manan Island, 18 sites from Deer Island, six sites from Campobello Island and six sites from Passamaquoddy Bay. Fish farmers, in concert with their veterinarians, generally perform intensive monitoring and control practices. However, there is a continued reliance on emamectin benzoate (SLICE^®) for sea lice control on Atlantic salmon farms in the Bay of Fundy, which raises concerns regarding the potential for sea lice to develop resistance to the drug.     

An evaluation of the duration of efficacy of emamectin benzoate in the control of Caligus curtus Müller infestations in Atlantic cod, Gadus morhua L

The duration of efficacy of emamectin benzoate in the control of Caligus curtus infestations in Atlantic cod, Gadus morhua L., was studied following an administration of 50 μg kg^?1 for seven consecutive days. No lice were found on medicated fish when challenged 1 week (challenge 1) or 5 weeks (challenge 2) following termination of medication, whereas the mean abundance of lice among the unmedicated fish was 17.9 and 19.3 lice per fish in challenge 1 and 2, respectively. Muscle concentrations of 19.5 ± 8.2 ng g^?1 and 3.4 ± 0.9 ng g^?1, respectively, and skin concentrations of 23.1 ± 10.8 and 4.2 ± 1.0 ng g^?1, respectively, were found 27 and 55 days following the termination of medication. Tissue concentrations and the duration of efficacy indicate a dosing regime for emamectin in cod, similar to the regime used for Atlantic salmon, Salmo salar L.