不同杀菌剂对烟草赤星病菌室内毒力测定

[目的]筛选防治烟草赤星病的有效药剂.[方法]采用菌丝生长速率法和孢子萌发法测定7种杀菌剂对烟草赤星病菌(Alternaria alternata)的毒力作用.[结果]菌丝生长速率法中56％啶酰·肟菌酯、50％啶酰菌胺、30％肟菌·戊唑醇、72％霜脲·锰锌、80％戊唑醇、30％丙硫菌唑、50％氯溴异氰尿酸的EC50值分别为0.1525,0.1603,0.2420,1.8137,4.5663,14.8457,86.9761 mg/L,孢子萌发法中50％啶酰菌胺、50％氯溴异氰尿酸、56％啶酰·肟菌酯、72％霜脲·锰锌、80％戊唑醇、30％肟菌·戊唑醇、30％丙硫菌唑的EC50值分别为0.1272,0.1333,0.2088,1.3191,1.8218,3.1282,27.0458 mg/L.供试的7种杀菌剂中对菌丝生长的抑制效果最好的是56％啶酰·肟菌酯,EC50值为0.1525 mg/L;对孢子萌发的抑制效果最好的是50％啶酰菌胺,EC50值为0.1272 mg/L.[结论]56％啶酰·肟菌酯和50％啶酰菌胺可优先作为烟草赤星病田间防治实验用药,72％霜脲·锰锌和30％肟菌·戊唑醇可用作交替使用杀菌剂.     

5种杀菌剂对水稻纹枯病及稻曲病防效试验研究

[目的]为明确不同杀菌剂对单季稻纹枯病及稻曲病的防治效果.[方法]对5种杀菌剂防治单季稻始病期纹枯病与盛发期纹枯病兼治稻曲病的田间试验.[结果]16％井冈·噻呋SC600 mL/hm2、32.5％苯甲·嘧菌酯SC600 mL/hm2、5％已唑醇SC1200 mL/hm2、25％吡唑醚菌酯SC600 mL/hm24种处理对单季稻始病期纹枯病均有较好的防控效果,药后27 d病指防效分别为90.7％、96.8％、88.7％、92.5％.在破口前5 d,16％井冈·噻呋SC900 mL/hm2、32.5％苯甲·嘧菌酯SC600 mL/hm2、75％肟菌·戊唑醇WG300 g/hm2、25％吡唑醚菌酯SC600 mL/hm24种处理对单季稻盛发期纹枯病也均有较好的综合防控效果,药后17 d以16％井冈·噻呋SC最佳,病指防效为88.6％,其次为25％吡唑醚菌酯SC、75％肟菌·戊唑醇WG、32.5％苯甲·嘧菌酯SC,病指防效分别为71.2％、67.1％、66.5％;4种杀菌剂对稻曲病病指防效分别为16.3％、58.2％、100％、76.4％,以75％肟菌·戊唑醇WG300 g/hm2效果最好,16％井冈·噻呋SC900 mL/hm2效果最差.[意义]研究结果可以为浙西北单季稻区纹枯病及稻曲病科学有效地进行化学防控提供参考.     

不同药剂防治柑橘脂点黄斑病田间药效试验研究

为了筛选柑橘脂点黄斑病的最佳防治药剂,指导大面积防治,选用60%吡唑醚菌酯·代森联水分散粒剂等5种杀菌剂进行田间药效对比试验。结果表明,75%肟菌酯·戊唑醇水分散粒剂和60%吡唑醚菌酯·代森联水分散粒剂对柑橘脂点黄斑病的防效分别达80.49%、74.22%,防治效果优于其他供试药剂。     

8种药剂对水稻穗颈瘟的田间防效简报

通过田间试验,评价分析8种杀菌剂防治水稻穗颈瘟效果及对水稻产量的影响。在试验设计用药量下,对水稻穗颈瘟最终防效由高到低的药剂依次为75%三环唑可湿性粉剂、9%吡唑醚菌酯微囊悬浮剂、13%春雷·三环唑可湿性粉剂、32.5%苯甲·嘧菌酯悬浮剂、75%肟菌·戊唑醇水分散粒剂、40%稻瘟灵乳油、250 g/L嘧菌酯悬浮剂、2%春雷霉素可溶性液剂。9%吡唑醚菌酯微囊悬浮剂、32.5%苯甲·嘧菌酯悬浮剂和75%肟菌·戊唑醇水分散粒剂对促进水稻增产效果最为明显。     

戊唑醇·肟菌酯75%水分散粒剂防治葡萄白腐病试验

露地葡萄白腐病在荆州区属于常见病害,在发病初期,用戊唑醇·肟菌酯75%水分散粒剂进行防治试验,2次药后12d防效达到92%以上,第3次药后14d代森锰锌防效达到87%,戊唑醇·肟菌酯防效达到93%以上。     

3种杀菌剂防治黄瓜白粉病的田间防效

选用3种杀菌剂进行黄瓜白粉病田间防治试验.发现42.8％氟菌·肟菌酯SC对黄瓜白粉病具有较好的防治效果,制剂用量为14 mL/667m2的处理对黄瓜白粉病的防效显著高于75％肟菌·戊唑醇WG 13.3 g/667m2和30％醚菌·啶酰菌SC 25.8 mL/667m2的防效,并且对黄瓜生长发育无不良影响.     

超高效液相色谱-串联质谱法测定肟菌酯和戊唑醇在稻田中的残留

建立了超高效液相色谱-串联质谱法测定糙米、谷壳、植株、土壤和稻田水中肟菌酯和戊唑醇残留的分析方法。结果表明,肟菌酯和戊唑醇在0.001~0.032mg/L范围内线性关系良好,相关系数分别为0.9995和0.9998,在0.02~2mg/kg添加水平下,肟菌酯和戊唑醇在糙米、谷壳、植株、土壤和稻田水中的平均回收率为79%~109%,相对标准偏差为2.3%~8.5%。肟菌酯和戊唑醇在糙米、谷壳、植株、土壤和稻田水中的定量限为0.02mg/kg。     

保护地草莓白粉病的防治药剂筛选

河南信阳保护地草莓白粉病为害较重,并已出现抗药性问题。为探寻安全、有效的防治药剂,对75%肟菌.戊唑醇WG、50%醚菌酯WG、10%苯醚甲环唑WG、25%三唑酮WP、75%百菌清WP进行了药效筛选试验。结果表明,75%肟菌.戊唑醇WG 3 000倍液、50%醚菌酯WG 3 000倍液的防效较好,均在80%以上,与其他药剂的防效差异显著,且对草莓安全、无害,可以在信阳地区作为防治草莓白粉病的药剂推广应用。     

超高效液相色谱-串联质谱法快速检测核桃中戊唑醇､肟菌酯及肟菌酸残留

建立了超高效液相色谱-串联质谱法(UHPLC-MS/MS)同时测定戊唑醇?肟菌酯及其代谢物肟菌酸在核桃中的残留检测方法?样品中待测农药组分采用2%乙酸乙腈溶剂振荡提取, 弗罗里硅土(florisil)净化, 利用乙腈和0.2%甲酸水作为流动相梯度洗脱, C18色谱柱分离, 在多反应监测模式下定量分析, 基质外标法定量?结果表明:戊唑醇添加水平为5~500 μg/kg时, 戊唑醇在核桃中添加回收率为80.3%~100.8%, 相对标准偏差(RSD)为2.5%~11.7%; 肟菌酯和肟菌酸添加水平为2~200 μg/kg时, 肟菌酯在核桃中添加回收率为91.1%~102.9%, 相对标准偏差(RSD)为1.7%~12.5%; 肟菌酸在核桃中添加回收率为91.7%~101.9%, 相对标准偏差(RSD)为3.7%~9.2%?戊唑醇?肟菌酯和肟菌酸溶剂标准曲线和基质标准曲线在1~1 000 μg/L范围内线性关系良好, 相关系数均大于0.99?戊唑醇定量限为5 μg/kg, 肟菌酯和肟菌酸定量限均为2 μg/kg?实际样品检测中, 戊唑醇残留结果为6~99 μg/kg, 肟菌酯残留结果为<2~103 μg/kg, 肟菌酸均小于检测限?该方法操作简便?快捷和准确, 满足在核桃实际样品中戊唑醇?肟菌酯及其代谢物肟菌酸的残留检测要求?     

75%戊唑醇·肟菌酯水分散粒剂防治水稻稻瘟病效果

试验用75%戊唑醇·肟菌酯水分散粒剂与对照药剂6%戊唑醇微乳剂对水稻稻瘟病进行防治效果评价。试验结果表明:该药剂对水稻稻瘟病有很好的防治效果,防效达到76%以上。建议在水稻破口抽穗期,采用75%戊唑醇·肟菌酯水分散粒剂1hm~2有效成分用量168.75g~225g(667m~2商品用量15g~20g),兑水675L进行喷雾防治,齐穗期再喷施1次,对水稻稻瘟病有较好的防治效果,具有较好的推广应用前景。     

福寿螺配偶个体大小选择性初步观察

通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。     

Localization of metabolic sites of action of herbicides

Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate ¹⁴C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides.     

厚朴病虫害种类的初步调查

采用标准地法和线路调查法,对湖北恩施市新塘乡双河厚朴基地的厚朴病虫害进行了系统调查,记录主要虫害13种,其中叶部害虫9种,枝干害虫2种,根部害虫2种。厚朴主要病害5种。藤壶蚧、厚朴枝角叶蜂和厚朴新丽斑蚜为湖北省首次报道,小绿叶蝉为厚朴新寄主记录种。同时记录了藤壶蚧的天敌6种,其中寄生小蜂2种,瓢虫4种;厚朴新丽斑蚜的天敌昆虫8种。对藤壶蚧、厚朴枝角叶蜂和厚朴苗木根腐病等重要病虫害的发生规律进行了初步调查,同时提出了防治建议。     

青稞种子带菌检测及杀菌剂消毒处理效果

为了研究青稞种子外部和内部携带真菌情况,比较不同杀菌剂对青稞种子的带菌消毒效果和对幼苗生长的影响,为青稞种子播前包衣处理和种传真菌病害防控提供依据,采用离体平皿法对云南迪庆‘云青1号’、‘云青2号’和‘短白青稞’3个主栽品种进行带菌检测,并对种子进行拌种或浸种处理测定6种杀菌剂对种子消毒效果,分析杀菌剂对种子发芽和幼苗生长的影响。结果表明:供试青稞种子表面携带的优势菌群为青霉(Penicilliumspp.)、镰刀菌(Fusariumspp.);种子内部寄藏的真菌主要为镰刀菌、核腔菌(Pyrenophoraspp.)、附球菌(Epicoccumspp.)、丝核菌(Rhizoctoniaspp.)、链格孢(Alternariaspp.)和木霉(Trichoderma spp.)。青稞不同品种的种子表面及内部携带的真菌种类差异较大。致病性测定表明,镰刀菌对种子萌发和幼苗生长影响最大,后期出现幼苗坏死现象。45%咪鲜胺EW、75%百菌清WP、50%福美双WP对青稞种子携带真菌均有显著抑制作用和消毒效果,50%福美双WP消毒效果最优,达100%;45%咪鲜胺EW、75%百菌清WP、50%福美双WP处理对青稞种子发芽和幼苗生长均无显著影响。     

Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato

The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.     

Mode of action of etoxazole

The mode of action of the 2,4-diphenyl-1,3-oxazoline acaricide/insecticide etoxazole has been argued to be moulting inhibition, but experimental results supporting this hypothesis are lacking. This study investigated the effect of etoxazole on chitin biosynthesis in the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Etoxazole induced moulting defects in fall armyworm larvae similar, if not identical, to those caused by benzoylphenylureas, a well-known class of insecticidal chitin biosynthesis inhibitors. Furthermore, in contrast to untreated larvae, the chitin content in the integuments of larvae several days after treatment did not differ from that in freshly ecdysed individuals, thus suggesting strong chitin biosynthesis inhibition in vivo. A more detailed investigation of the inhibitory potential by incubating cultured integument pieces from larvae of S. frugiperda with [14C]N-acetyl-D-glucosamine, a radiolabelled chitin precursor, revealed I50 values of 2.95 and 0.071 microM for etoxazole and triflumuron respectively. The incorporation of radiolabel into potassium hydroxide-resistant material was inhibited by etoxazole in a dose-dependent manner. Based on these results, it is concluded that the acaricidal and insecticidal mode of action of etoxazole is chitin biosynthesis inhibition.     

Measures of durability of resistance

ABSTRACT Conventional models for the durability of resistant cultivars focus on the dynamics of the frequency of resistance genes. This leads to a definition of the durability of resistance as the time from introduction of the cultivar to the time when the frequency of the virulence gene reaches a preset threshold. It is questionable whether this is the most appropriate way to measure durability. Here we use a simple epidemiological model to link population dynamics and population genetics to compare three measures of durability: (i) the expected time until invasion of the virulent genotype, by mutation or immigration, and subsequent establishment of a population (T(invasion)); (ii) the virulence frequency related measure of the time for the virulent genotype to take-over the pathogen population ( T(take-over)); and (iii) the additional yield, measured by the additional number of uninfected host growth days (T(additional)). Specifically, we show how the measures of durability are affected by deployment and epidemiological parameters. We use a combination of numerical solution and analytical approximation of a model for the population dynamics of avirulent and virulent genotypes of a pathogen growing in dynamically changing populations of resistant and susceptible cultivars. The three measures of durability are compared. Some consequences of the results for durable resistance in multilines and mixtures and the regional deployment of resistant cultivars are discussed.     

甲基硫菌灵标样的制备

本文介绍了用进口甲基硫菌灵样品，采用溶剂萃取，高速离心，重结晶，高效液相色谱，红外光谱等分析方法进行系统分离与鉴定，得到其标样的方法。