稻瘟病药剂防治试验

稻瘟病 (Ｐｙｒｉｃｕｌａｒｉａｇｒｉｓｅａ)是浙江省水稻主要病害之一。目前用于防治稻瘟病的主要药剂是三环唑 ,该药剂在浙江省使用已近２０年 ,由于单一品种的长期使用 ,容易诱发病菌对药剂的抗药性 ,现已发现三环唑在浙江省的有些地区防效有所下降 ,可能与病菌的抗药性有关。为了延缓病菌的抗药性产生 ,迫切需要研制或筛选防治稻瘟病的新药剂。为明确其对稻瘟病的防治效果 ,我们在浙江省龙游、淳安进行了２０%清道夫悬浮剂、２０ %三环·异稻可湿性粉剂防治稻瘟病田间小区药效试验 ,取得了较满意的防治效果。１材料和方法１．１供试药…     

45%瘟特灵胶悬剂防治稻瘟病小区试验及大田示范

稻瘟病(Pyricu’aria oryzae)是水稻主要病害之一,严重影响水稻高产稳产。目前,防治稻瘟病的有效药剂常常不能适应农业生产的需求,稻瘟病菌又易产生抗药性,稻瘟净、富士一号等的防治效果已欠佳,因而寻找新农药仍有必要。 1989年我们承担了全国大田药效试验网提供的广东省江门市农药厂以三环唑加硫磺生产的复合新剂型—45％瘟特灵胶悬剂防治叶瘟和穗瘟的小区试验,防治效果很好。 由于穗瘟对水稻产量影响较大,1991年     

几种农药对稻瘟病预防与治疗效应

1988年—1992年我们连续承担新农药对稻瘟病防治试验,先后对参试药剂多次地进行了系统的试验研究。此文主要报道在室内人工控制下参试药剂对稻瘟病的预防和治疗效应的精确试验结果,为因地制宜选用药剂及科学合理地防治稻瘟病提供科学依据。     

生物农药在稻瘟病防治中的应用及前景分析

稻瘟病是一种世界性稻作病害,是影响高产、稳产的重要因素。目前利用抗病品种和化学农药是防治稻瘟病的主要措施,但是稻瘟病菌生理小种易变异,抗病品种选育时间较长,化学农药的残留污染环境,寻找有效的生物防治途径对于水稻产业可持续发展迫在眉睫。生物农药具有低残留、高效、对环境无污染、病原菌不易产生抗药性等优点,是防治稻瘟病的重要杀菌剂。在稻瘟病防治中常用的生物农药包括微生物源农药、植物源农药和植保素。本文主要综述了生物农药在稻瘟病防治中的生防机制与应用研究现状,分析生物农药在稻瘟病防治中的前景。     

小麦白粉病菌对三唑酮抗药性的监测

小麦白粉病是世界性病害,因缺少抗性品种,长期以来依赖于药剂防治。三唑类药剂是防治白粉病的高效药剂,由于长期、大量、单一的应用,致使病菌抗药性发生。我国胶东沿海是小麦白粉病的多发地区,使用三唑酮防治该病近10年,病菌抗药性的研究与探明对农业生产具有指导意义。应用小株法和叶段法进行小麦白粉菌对三唑酮抗药性监测,3年共监测单孢堆菌系333个。结果较基线MIC高3～7倍者占86％,表明已进入抗药性发展初期。由于近年春旱抑制发病而抗药性发展很慢,一旦白粉病有中度以上流行条件,大面积连续用药即会发生抗药性,使防治失效,威胁生产,建议尽早治理。     

为什么要用加收米?

<正>常规稻瘟病防治药剂如三环唑、稻瘟灵等,由于长期单一使用,稻瘟病均已产生了明显的抗药性,造成喷药浓度提高,成本增大,防治效果下降,甚至个别地方出现大米农药残留超标等不良后果,而且这些常规药剂对水稻叶鞘腐败病、叶鞘褐变病、细菌性褐班病无防效。经过多年的生产实践证明:2%加收米能有效防治水稻生育期间的多种真菌、细菌引起的病害,而且安全低毒、无残留,符合当前绿色食品的生产标准。     

施稻灵防治穗颈瘟药效试验

稻瘟病是我市水稻的主要病害之一,现多使用三环唑或其复配制剂进行防治,药剂品种较单一。为开发防治稻瘟病的新药剂,特于１９９７年９月～１０月进行了６％施稻灵悬浮剂防治晚稻穗颈瘟试验,结果如下：一、供试药剂及试验方法１．供试药剂及用量：６％施稻灵悬浮剂（贵...     

球孢白僵菌对草坪夜蛾类害虫防治效果的研究

选用球孢白僵菌与其他5种杀虫剂对草坪夜蛾类害虫进行防治试验,药后7d球孢白僵菌对夜蛾类幼虫的防效优于其他供试药剂;生物制剂类杀虫剂的防效优于常规杀虫剂.建议在虫口基数不大的情况下选用球孢白僵菌防治草坪夜蛾类害虫,并适时进行药剂轮换以降低抗药性风险.     

柑橘螨类害虫发生特点与药剂防治

螨类害虫是危害柑橘的主要害虫之一。它适应性强，繁殖率高，危害猖獗，且易产生抗药性。因此，防治柑橘螨类害虫，必须了解其发生特点，把握关键时期，科学使用农药，才能达到经济效的目的。现将柑橘螨类害虫发生特点与药剂防治简介如下，供参考。     

植物病原菌抗药性遗传研究

 植物病原菌对杀菌剂的抗药性是由遗传基因控制的,抗药基因位于细胞质遗传因子或细胞核染色体基因上,细菌对许多药剂如铜制剂、链霉素等的抗药性和真菌对少数药剂如甲氧丙烯酸酯类药剂的抗性属于前一种情况,而真菌对大多数药剂的抗性则属于后一种情况。核基因控制的抗药性又可分为主效基因(major-gene)抗性和微效多基因(poly-gene)抗性,分别使病菌对药剂的抗性表现质量性状和数量性状。病原菌对苯并咪唑类药剂、春日霉素、羧基酰胺类药剂、苯酰胺类药剂、芳烃类药剂、二甲酰亚胺类药剂等的抗性通常为主效基因控制;使病菌表现微效多基因抗性的杀菌剂主要有多果定、羟基嘧啶类药剂、甾醇合成抑制剂(SBIs)等     

三种化学物质诱导观赏百合青霉病抗性的研究

采用水杨酸、纳米硅、氯化铵等3种化学物质对观赏百合青霉病的抑菌活性和诱抗效果进行了测定。结果表明,3种化学物质对观赏百合青霉病菌抑菌率较低,最高仅为5.6%。3种化学物质处理百合鳞茎后,表现出较高诱导抗病性。在100、50和25μg/ml浓度下,水杨酸的诱导抗病效果最好,分别为79.09%、69.28%和61.96%。浓度为100μg/ml的水杨酸、纳米硅和氯化铵处理观赏百合鳞茎后,再进行挑战接种,1d后鳞茎组织内过氧化物酶、苯丙氨酸解氨酶、β-1,3-葡聚糖酶活性明显高于对照。浓度为100μg/ml的3种化学物质处理百合种球在2℃条件下贮存4个月后,青霉病的发病率和病情指数均低于对照;水杨酸、纳米硅和氯化铵处理的诱导防治效果分别为60.89%、55.56%和35.31%;处理种球种植后能够正常萌发,出苗率分别为91.67%、90.83%、90.83%。     

Natural products in plant protection

Natural products can be used to control pests and diseases in crops. These products include anorganic compounds, but also a variety of plant extracts. In the beginning of this century active microbial extracts were discovered as well. Synthetic crop protection chemicals were developed from about 1940 onwards and sustained progress in modern agriculture. The first generation chemicals have aspecific modes of toxic action and are in many instances deleterious to the environment. The second generation chemicals have specific modes of action and meet modern environmental requirements. A disadvantage of these chemicals is the potency of target organisms to acquire resistance. This condition urged agrochemical industry to develop chemicals with new modes of action. Such chemicals can be developed by using natural bioactive products as leads in synthesis programmes. This paper decribes the progress that was made in the development of natural bioactive compounds in pest and disease control.     

Natural products in plant protection

Natural products can be used to control pests and diseases in crops. These products include anorganic compounds, but also a variety of plant extracts. In the beginning of this century active microbial extracts were discovered as well. Synthetic crop protection chemicals were developed from about 1940 onwards and sustained progress in modern agriculture. The first generation chemicals have aspecific modes of toxic action and are in many instances deleterious to the environment. The second generation chemicals have specific modes of action and meet modern environmental requirements. A disadvantage of these chemicals is the potency of target organisms to acquire resistance. This condition urged agrochemical industry to develop chemicals with new modes of action. Such chemicals can be developed by using natural bioactive products as leads in synthesis programmes.This paper decribes the progress that was made in the development of natural bioactive compounds in pest and disease control.     

Pyrethroid resistance discovered in a major agricultural pest in southern Australia: the redlegged earth mite Halotydeus destructor (Acari: Penthaleidae)

BACKGROUND: The redlegged earth mite (Halotydeus destructor Tucker) is an important pest of field crops and pastures. Control of this pest relies heavily on chemicals, with few genuine alternatives presently available. Pesticide responses of H. destructor from the field with reported chemical control failures were compared with mites from susceptible 'control' populations. Toxicology bioassays were conducted on adult mites across multiple generations. RESULTS: Very high levels of resistance to two synthetic pyrethroids, bifenthrin and alpha-cypermethrin, were detected in this species for the first time. For bifenthrin, LC(50) estimates showed a difference in resistance of greater than 240 000-fold. Resistance to alpha-cypermethrin was almost 60 000-fold. This resistance was shown to be heritable, persisting after several generations of culturing. There was no evidence that resistance to organophosphorus chemicals had evolved, which is likely to be a direct consequence of the history of chemical applications these mites have experienced. CONCLUSION: These results highlight the need for more judicious management decisions in order to control pest species in a sustainable manner. The implications of these findings in regard to the management and future research of the redlegged earth mite are discussed.     

羧酸酰胺类(CAAs)杀菌剂研究进展

羧酸酰胺类(Carboxylic acid amides, CAAs) 化合物是一类对卵菌病害具有优异防治效果的新型杀菌剂。该类杀菌剂由3组化学结构各不相同的化合物组成,包括肉桂酰胺、缬氨酰胺氨基甲酸酯和扁桃酰胺类。由于这3类杀菌剂具有相似的杀菌活性且相互间存在正交互抗药性,国际杀菌剂抗药性行动委员会已于2005年底将这3类具有不同化学结构的杀菌剂归为羧酸酰胺类杀菌剂。对CAA类杀菌剂的化学结构特征、生物学活性、作用机制与抗药性的最新研究进展进行了综述。     

Occurrence in Italy and characteristics of lettuce downy mildew (Bremia lactucae) resistant to phenylamide fungicides

Control of lettuce downy mildew (Bremia lactucae) with phenylamide fungicides has failed in some intensive lettuce-producing areas in Northern Italy since Spring 1993. Before then, these chemicals and particularly metalaxyl, provided the best disease control. The sensitivity of Bremia lactucae isolates collected in such areas to metalaxyl was evaluated in the laboratory. These strains grew and sporulated profusely on lettuce seedlings treated with 100 and 200 ppm of metalaxyl, whereas sensitive control strains were completely inhibited when treated with fungicide concentrations ranging from 0.5–1 ppm. Thus in Italy occurrence of resistance to phenylamide fungicides in Bremia lactucae has also been demonstrated, as in almost all the countries where these chemicals were previously authorised. Subsequently, a demonstration of occurrence of resistance was made and the virulence pattern of several strains (resistant and sensitive to metalaxyl) was characterised using differential NL series containing the 13 DM resistant genes or R factors. The results suggest the occurrence of a new pathotype in Italy different from all the 16 NL Bremia lactucae races studied.     

杀虫剂的作用方式与分类

随着杀虫剂产品的逐渐增多,按照其作用方式进行分类显得十分重要,不仅有利于新化合物的合成与筛选,而且有助于了解其抗药性以及科学地使用。本文收集了杀虫剂(杀螨剂)共253种,分属19种不同的作用方式和60种不同的化合物类别。     

化学诱抗剂诱导金银花抗白粉病效果研究

用壳聚糖、草酸、水杨酸、葡聚糖、硅酸钠、硫酸亚铁、氟乐灵、磷酸氢二钾等8种药剂在不同株龄金银花上进行了对白粉病的诱导抗性试验。结果表明壳聚糖、草酸对金银花白粉病有良好的诱导抗性,在1年生、2年生和4年生金银花上对白粉病的平均防治效果分别达82.3%、59.9%和72.1%,54.9%、58.4%和74.1%。水杨酸、硅酸钠、硫酸亚铁有一定的诱导效果,但不稳定。葡聚糖和磷酸氢二钾无明显诱导抗病作用,氟乐灵则有促进发病的作用。     

三种化学物质诱导观赏百合对黑斑病抗性的研究

［目的］ 确定水杨酸、纳米硅、草酸铵等3种化学物质对观赏百合黑斑病抗病性的诱导效果,为百合生长期病害的防治提供理论依据。［方法］ 测定3种化学物质对观赏百合黑斑病菌的抑菌活性和诱导寄主抗性效果。［结果］3种化学物质对观赏百合黑斑病菌抑菌率较低,最高仅为5.43%,但处理百合叶片后,诱导百合产生较高抗病性。在100、50 μg/mL和25 μg/mL浓度下,纳米硅的诱导抗病效果最好,分别为55.55%、60.69%、48.57%。水杨酸诱导处理可使观赏百合叶片β-1,3-葡聚糖酶在第1 天达到峰值,纳米硅可以使过氧化物酶在第5天达到峰值,草酸铵可以使苯丙氨酸解氨酶在第5天达到峰值,分别为对照的3.95倍、2.10倍和1.15倍;先诱导处理再接种黑斑病菌1 d后叶片组织内β-1,3-葡聚糖酶、过氧化物酶、苯丙氨酸解氨酶活性均明显高于对照;水杨酸、纳米硅和草酸铵处理7 d后田间诱导防病效果分别为35.38%、43.55%和31.07%;处理14 d后,与第7天相比诱导防病效果明显降低。［结论］水杨酸、纳米硅和草酸铵3种化学物质对百合均有一定诱导抗病作用,其中纳米硅酸的诱导抗病效果最好,可达到48%以上。     

Responses of striped stem borer,Chilo suppressalis (Lepidoptera: Pyralidae), from Taiwan to a range of insecticides

BACKGROUND: Information on the insecticide susceptibility of striped stem borer, Chilo suppressalis (Walker), is essential for an effective pest management programme. An early detection of resistance development can prompt the modification of current control methods and increase the lifespan of insecticides through the rotation of chemicals with different modes of action. In this study, the susceptibility of this pest in Taiwan to four classes of insecticides has been examined. RESULTS: Over 1000‐fold resistance to carbofuran was detected in C. suppressalis collected from Chiayi and Changhua prefectures, with estimated LC₅₀ values of > 3 mg cm^?2. In addition, 61‐fold resistance to cartap was found in the Chiayi population. On the other hand, all tested populations of rice stem borer were still relatively susceptible to chlorpyrifos, fipronil and permethrin, with LC₅₀ values ranging from 30 to 553 ng cm^?2. Chilo suppressalis populations collected from the central parts of Taiwan have a higher degree of resistance to the tested insecticides than those from northern areas. CONCLUSION: The occurrence of high resistance to carbofuran in the Chiayi and Changhua areas suggests that this compound should be replaced with chemicals having a different mode of action, such as chlorpyrifos, fipronil and permethrin, to which low cross‐resistance has been detected. Copyright © 2010 Society of Chemical Industry