53．8％可杀得2000DF防治番茄早疫病药效试验

田间试验结果表明,可杀得2000DF对温室内番茄早疫病具有较好的防效,能有效控制病害的扩展蔓延。田间适宜使用浓度为800－1100倍,持效期可达10天以上。     

灰葡萄孢代谢产物对3种小麦病害的抑制作用

分别用皿内试验和盆栽试验方法测定灰葡萄孢代谢产物对3种小麦病原菌的抑制作用。皿内试验结果表明,灰葡萄孢代谢产物对小麦纹枯病菌菌丝生长抑制率可达到66.2%,对小麦根腐病菌菌丝生长抑制率达到61.6%,对小麦全蚀病菌菌丝生长抑制率为12.5%。盆栽试验结果表明,在发病前喷施灰葡萄孢代谢产物培养液,对小麦纹枯病的预防效果可达97.6%,以上对小麦根腐病的预防效果可达84.6%。将灰葡萄孢代谢产物培养液稀释20倍后喷施,对小麦纹枯病和小麦根腐病的预防效果也分别可达60.7%和42.3%。盆栽试验中灰葡萄孢代谢产物对小麦纹枯病和小麦全蚀病的治疗作用效果分别为48.3%和29.7%,对小麦根腐病的治疗效果不明显。     

中药大黄对番茄早疫病菌抑菌作用的初步研究

采用15种中药材的乙醇提取液,对番茄早疫病菌进行抑菌实验,结果表明,15种中药材乙醇提取物对番茄早疫病菌均表现出不同程度的抑制作用,其中大黄的抑菌效果最好,抑制率为93.9%,最低抑菌浓度为0.015625g·m L-1,并且对菌丝生长具有一定抑制作用。大黄药液处理后可造成病原菌的孢子畸形,处理12h后萌发率仅为4.75%,为研制和开发新型植物源农药提供理论依据。     

海芋甲醇提取物的抑真菌作用

采用生长速率法测定了海芋的不同部分甲醇提取物对水稻纹枯病菌等15种植物病原真菌的生物活性。结果表明：海芋叶、茎和叶柄的甲醇提取物对荔枝霜疫霉病菌、稻瘟病菌和白菜黑斑病菌等有一定的活性;在10mg／mL的浓度下,海芋叶、茎和叶柄的甲醇提取物对水稻纹枯病菌菌丝生长的抑制率分别为53．45％、43．15％和41．14％;海芋叶甲醇提取物对水稻纹枯病菌的EC50值为8．52mg／mL。海芋叶甲醇提取物的石油醚、氯仿、乙酸乙酯和正丁醇萃取组分对水稻纹枯病菌的活性研究表明,氯仿层的活性最高,抑制率为89．12％。海芋叶甲醇提取物的氯仿萃取物对水稻纹枯病菌的EC50值为2．13mg／mL.     

创新杀菌剂对土传病原真菌的离体活性测定

[目的]为了研究杀菌剂对尖孢镰刀菌、立枯丝核菌、瓜果腐霉菌的生物活性,采用菌丝生长速率法对多种杀菌剂及其混剂组合进行了离体抑菌活性测定.[结果]啶菌(恶)唑和苯醚甲环唑对黄瓜枯萎病菌的EC50值分别为0.3233、0.6604 mg/L;三环菌胺和甲霜灵对黄瓜猝倒病菌的EC50值分别为1.0282、2.5163mg/L.啶菌(恶)唑与苯醚甲环唑、三环菌胺与甲霜灵两两配比组成混剂,不同混剂组合在部分配比中共毒系数大于120,表现出增效作用.[结论]毒力测定结果表明:啶菌(恶)唑、苯醚甲环唑、三环菌胺和甲霜灵分别对3种病菌表现出了很强的抑制作用;啶菌(恶)唑·苯醚甲环唑(1∶5)、三环菌胺·甲霜灵(1∶3和1∶5)分别对病菌表现出了明显的增效作用.     

Effect of Different Concentrations of Ozone on in Vitro Plant Pathogens Development,Tomato Yield and Quality,Photosynthetic Activity and Enzymatic Activities

ABSTRACT

As an effective alternative to traditional pesticides, ozonated water has been used for direct immersion and spraying applications, respectively, against the pathogenic bacterium Ralstonia solanacearum (R. solanacearum) and fungus Alternaria solani (A. solani) that are pathogens of tomato. Immersing R. solanacearum in 0.8 mg/L ozonated water resulted in complete inactivation, while the growth-inhibition rates of the A. solani radial mycelia gradually increased with a 67.0% decrease compared to those of the control at an ozonated water concentration of 7.5 mg/L. This indicated that ozonated water was effective at restraining pathogens in the tomato plant. In addition, spraying wild tomato species (Solanum lycopersicum) plants with ozonated water at concentrations below 10 mg/L for 25 d had no negative effects after treatment compared to those of the control. Photosynthetic activities and the antioxidant system response in the untreated and ozonated water-treated plant leaves had no observable changes. To determine the optimal ozonated water concentration for the pathogen and its host plant, we examined a variety of modes of action, and then, below 10 mg/L of ozonated water. Thus, ozonated water not only inhibits the proliferation of plant pathogens, but is an effective alternative to the pesticides traditionally used to prevent disease in agricultural production.     

氯胺磷与井冈霉素对草坪褐斑病菌联合毒力测定

在室内恒温的条件下,用菌落直径法和毒力实验分别测定了氯胺磷、井冈霉素及其5种配比的混剂对草坪褐斑病菌（Rhizoctonia solani AG-1-IB融合群）的菌丝抑制作用和毒力．结果表明：质量分数85％氯胺磷原药和质量分数5％井冈霉素水剂对草坪褐斑病病菌的抑菌浓度区间分别为51．2～2000μg／mL、4．9～20000μg／mL,ECso分别为476．7μg／mL、488．6μg／mL,85％氯胺磷原药对草坪褐斑病病菌的毒力大于质量分数5％井冈霉素水剂;该两种农药以2：1混合时的ECso为275．8μg／mL,其增效系数达到了1．74．     

几种新型吡啶酮类杂环化合物对草坪褐斑病菌的毒力测定

采用菌落直径含毒介质法,对10种新型吡啶酮类杂环化合物以及井冈霉素对草坪褐斑病菌的抑菌活性进行了测定,结果表明:在测定浓度为200μg/mL的情况下,10种新型吡啶酮类杂环化合物对草坪褐斑病菌抑菌率达4.64%～67.33%,井冈霉素的抑菌率为43.27%。其中,化合物3-氰基-5(4-吡啶基)-4-正丙基-吡啶酮和3-氰基-5-苯基-6-甲基-1-(4-吡啶甲基)-吡啶-2(1H)酮的抑菌率最高,分别为67.33%、49.89%,抑菌活性高于井冈霉素;其他8个化合物抑菌活性均低于井冈霉素。