洋葱根腐病防治药剂筛选试验

[目的]筛选防治洋葱根腐病的有效药剂。[方法]在室内药剂筛选基础上,进行化学药剂筛选的同时,将其与生防菌复配,开展不同药剂田间药效试验。[结果]哈茨木霉菌和15%多菌灵复配对洋葱根腐病的防治效果明显,可增产27.6%。[结论 ]哈茨木霉菌和15%多菌灵复配进行洋葱根腐病的防治,具有防治过程农药毒性小,持效期长,能有效防治洋葱根腐病,降低环境污染的特点,生产中可作为防治洋葱根腐病的有效药剂推广使用。     

小麦蠕孢菌叶枯病菌室内药剂筛选

[目的]筛选对小麦蠕孢菌叶枯病菌具有较强抑制效果的药剂。[方法]利用生长速率法测定了5种不同杀菌机制的杀菌剂对小麦蠕孢菌叶枯病菌的毒力。[结果]5种杀菌剂对小麦蠕孢菌叶枯病菌的作用效果差异很大,其中咪鲜胺对小麦蠕孢菌叶枯病菌菌丝的抑制作用最强,EC50仅为0.067μg/ml;苯醚甲环唑、戊唑醇、噻呋酰胺的抑制作用次之,EC50在0.102～0.372μg/ml;多菌灵的抑制作用最小,EC50为30.588μg/ml。[结论]对小麦蠕孢菌叶枯病菌安徽分离株有较好抑制作用的药剂是咪鲜胺、苯醚甲环唑和戊唑醇。     

Efficacy of fosetyl-Al,propamocarb, dimethomorph,cymoxanil, metalaxyl and metalaxyl-M in Czech Pseudoperonospora cubensis populations during the years 2005 through 2010

A total of 134 Czech Pseudoperonospora cubensis isolates originating from Cucumis sativus were used for fungicide resistance screening. Efficacy of six commonly used and registered fungicides was screened in Czech P. cubensis populations. The investigations covered the frequency and occurrence of sensitive, moderately resistant and resistant isolates to the individual fungicides during the period 2005–2010. Fosetyl-Al (Aliette 80 W) and propamocarb (Previcur 607 SL) were the most effective fungicides. All tested isolates were sensitive on all tested fosetyl-Al concentrations. However, some isolates expressed resistance (profuse sporulation) or moderate resistance (limited sporulation) to lower and/or even to recommended concentrations of propamocarb in the years 2006 and 2008–2010. Metalaxyl (Ridomil PLUS 48 WP) and metalaxyl-M (Ridomil Gold MZ 68 WP) were ineffective. Isolates collected in 2008 and 2009 showed large variation in moderate resistance or resistance even at high fungicide dosages. However, this result was not confirmed in 2010, when efficacy of these fungicides increased slightly, and 69% and 43% of isolates were controlled at the recommended concentration of metalaxyl-M and metalaxyl, respectively. Limited or profuse sporulation was observed only sporadically at high concentrations. Sensitivity of isolates to cymoxanil (Curzate K) differed among the studied years. While cymoxanil was ineffective in the years 2005–2008 and in 2010, 68% of isolates were controlled at the recommended concentration in 2009. During the years 2005 through 2010, a shift towards higher sensitivity to dimethomorph was observed at all screened concentrations.     

杧果蒂腐病菌对多菌灵的抗药性测定及其杀菌剂筛选

对来自海南3个地区的86个杧果蒂腐病菌(Botryodiplodia theobromae Pat.)菌株进行了对多菌灵的抗药性测定,结果表明,杧果蒂腐病菌群体中存在着对多菌灵抗性的群体。采用生长速率法进行了23种杀菌剂对4株杧果蒂腐病菌的室内毒力测定,通过EC50值、EC90值及与多菌灵的交互抗性等的综合分析,结果表明,作为防治杧果蒂腐病的首选药剂有咪鲜胺锰盐、丙环唑、氟硅唑、咪鲜胺、异菌脲、苯醚甲环唑、戊唑醇、腈菌唑、吡唑醚菌酯和井冈霉素10种杀菌剂,可选杀菌剂还有百菌清和代森锰锌。杧果蒂腐病菌除对多菌灵产生抗性外,还对甲基硫菌灵、醚菌酯和烯唑醇3种杀菌剂产生了抗药性。通过交互抗性分析,多菌灵、甲基硫菌灵和烯唑醇3种杀菌剂之间存在交互抗性,而醚菌酯与井冈霉素之间存在负交互抗性。为了避免杧果蒂腐病菌对某种杀菌剂产生抗药性,建议上述可选用杀菌剂交替使用。     

6种不同杀菌剂对小麦赤霉病的防治效果及对小麦产量的影响

[目的]筛选防治赤霉病的有效药剂.[方法]以济宁16为材料,研究了多菌灵、三唑酮、戊唑醇、咪鲜胺、丙森锌、唑醚·代森联6种杀菌剂对小麦赤霉病的田间防治效果.[结果]2013、2014年试验结果表明6种杀菌剂2次喷雾的平均病情指数防治效果均在60％以上,且产量增加显著,其中唑醚·代森联、咪鲜胺、丙森锌、戊唑醇的病指防效显著好于常规药剂多菌灵、三唑酮,可作为防治小麦赤霉病的药剂交替使用.[结论]为生产上小麦赤霉病的药剂防治提供了参考.     

6种杀菌剂对番茄早疫病的毒力测定

采用菌丝生长速率抑制法测定了6种杀菌剂对番茄早疫病的抑菌作用,并得到了6个毒力回归方程及抑制有效中浓度(EC<,50>).结果表明,6种杀菌剂对番茄早疫病病原菌的生长均有抑制作用,但不同药剂之间有差异,对番茄早疫病病原菌的EEC<,50>由低到高依次为25%金力士乳油、25%巨佳乳油、10%世高水分散粒剂、70%纳米欣...     

11种杀菌剂对小麦黑胚病菌的室内毒力测定

采用PDA平板和凹玻片法分别测定了11种杀菌剂对小麦黑胚病菌菌丝生长和孢子萌发的抑制作用,结果表明,适乐时对病菌孢子萌发和菌丝生长的抑制活性都最强,EC50分别为1.45×105mg/kg和0.10mg/kg;科博、敌力脱、扑海因、敌畏丹对病菌孢子萌发的抑制活性也较强,EC50分别为0.04mg/kg,0.16mg/kg,0.16mg/kg,0.71mg/kg;敌力脱、扑海因和敌畏丹对小麦黑胚病菌菌丝生长的抑制活性较强,EC50分别为1.70mg/kg和1.74mg/kg。     

植物性杀菌剂研究进展

植物性杀菌剂经不断研究,目前已发现许多植物具有杀真菌,细菌和钝化病毒的作用,并正在进一步开发,利用,希望能得到高效,优质,经济的新一类杀菌剂。     

腐霉利对木霉菌控制草莓灰霉病防治效果的影响

生防菌木霉与灰霉病菌具有较强的拮抗作用,本试验通过盆栽试验和大田试验,研究单独施用木霉菌、化学杀菌剂腐霉利以及二者以不同比例混合配制对草莓灰霉病的防治效果,探究化学杀菌剂腐霉利对生防菌防效的影响。结果表明:盆栽试验中,单独施用木霉菌对灰霉病的防效为81.40%,当木霉菌与腐霉利以质量比8∶1混配时,防效高达88.32%,二者以其他比例混配的防效在65%~80%之间,均高于单独施用腐霉利。木霉菌与腐霉利以8∶1或3∶1的质量比混配,对灰霉病的田间防治效果较好,在80%左右,且对草莓安全、无药害。以一定比例添加化学杀菌剂腐霉利可提高生防菌木霉防效的稳定性,并且可延缓病原菌对化学杀菌剂抗药性的产生。     

Sensitivity of Cercospora beticola isolates from Serbia to carbendazim and flutriafol

Cercospora beticola, causal agent of Cercospora leaf spot (CLS) of sugar beet, is primarily controlled by fungicides. Benzimidazole and demethylation inhibiting fungicides, including carbendazim and flutriafol, have been widely used in Serbia. Since these fungicide groups have a site-specific mode of action, there is a high risk for developing resistance in target organisms, which is the most important limiting factor in Cercospora leaf spot chemical control. A rapid identification of flutriafol and carbendazim resistance can help researchers in examining the potential of different fungicide resistance management practices, as well as in selection of fungicides for use in the areas where resistance has occurred. One hundred single-conidia isolates were collected from 70 representative locations of the sugar beet production region in Serbia. Evaluation of the isolates' sensitivity was based on the reduction of mycelial growth on medium amended with 1.25 μg mL⁻¹ flutriafol and 5 μg mL⁻¹ carbendazim. Resistance to flutriafol and carbendazim was detected in 16% and 96% of the tested isolates, respectively. All isolates resistant to flutriafol were resistant to carbendazim as well, which is the first report of a double resistance to fungicides in C. beticola. Detection of the isolates resistant to flutriafol and carbendazim using Cleaved Amplified Polymorphic Sequence (CAPS) markers confirmed the results of the in vitro tests. The efficacy of carbendazim, flutriafol, azoxystrobin, and tetraconazole at commercially recommended doses was evaluated in field trials where sugar beet plants in plots were inoculated with a mixture of isolates either sensitive and/or resistant to flutriafol and carbendazim. Carbendazim and flutriafol efficacy was very low in plots inoculated with isolates resistant to these fungicides. Presented results will contribute to development of a pathogen population sensitivity monitoring strategy that could be used for an effective CLS management in the region.