山东省和河北省黄瓜霜霉病菌对烯酰吗啉及双炔酰菌胺的抗性监测

 为明确黄瓜霜霉病菌对烯酰吗啉及双炔酰菌胺的抗性时空动态及这两种药剂对黄瓜霜霉病的田间防效,采用叶盘漂浮法检测了2011~2016年采自河北省和山东省黄瓜主产区的霜霉病菌1 821个菌株对烯酰吗啉及双炔酰菌胺的敏感性,并采用茎叶喷雾法对这两种药剂的田间防效进行评估。结果表明:黄瓜霜霉病菌1 821个菌株对烯酰吗啉和双炔酰菌胺抗性频率分别为88.5%和34.3%,供试菌株中对烯酰吗啉的低抗菌株及对双炔酰菌胺的敏感菌株占优势,平均抗性倍数分别为8.92和2.44,抗性指数分别为0.42和0.27。黄瓜霜霉病菌对这两种药剂的抗性频率、抗性倍数及抗性指数随着监测年限及地域的不同而波动。在河北定兴和山东寿光日光温室进行的田间药效试验中,按照药剂田间推荐剂量喷施4次,50%烯酰吗啉可湿性粉剂和250 g·L^-1双炔酰菌胺悬浮剂对黄瓜霜霉病表现出良好的防效(85%以上),与两地黄瓜霜霉病菌对烯酰吗啉产生低抗、对双炔酰菌胺敏感的监测结果一致。由此推断,50%烯酰吗啉可湿性粉剂和250 g·L^-1双炔酰菌胺悬浮剂可在对甲霜灵(或精甲霜灵)、噁霜灵及嘧菌酯普遍产生抗性的地区,作为58%甲霜灵·代森锰锌WP、68%精甲霜灵·代森锰锌WG、64%噁霜灵·代森锰锌WP 和250 g·L^-1嘧菌酯SC的替代药剂单独使用或与不同作用机理的杀菌剂混用,防治黄瓜霜霉病。     

河北省和山东省黄瓜霜霉病菌对氟吡菌胺的抗性及常规药剂对黄瓜霜霉病的田间防效

为明确黄瓜霜霉病菌Pseudoperonospora cubensis对氟吡菌胺的抗性时空动态,2011—2016年从河北省和山东省黄瓜主产区采集1 821株霜霉病菌,采用叶盘漂浮法检测供试菌株对氟吡菌胺的敏感性,并以茎叶喷雾法评估5种常规药剂对黄瓜霜霉病的田间防效。结果表明,河北省和山东省黄瓜主产区的黄瓜霜霉病菌对氟吡菌胺已普遍产生了低度抗性,平均抗性倍数为5.86;所有供试菌株的抗性频率为51.89%,其中低抗菌株及中抗菌株分别占36.18%和15.71%;平均抗性指数为0.34,每年检测的抗性频率、抗性倍数及抗性指数呈增长趋势,且随着监测区域的变化而变化。在河北省定兴县和山东省寿光市进行的田间防效试验结果显示,按推荐剂量喷施,687.5 g/L氟吡菌胺·霜霉威盐酸盐SC对黄瓜霜霉病防效显著高于常规对照药剂68%精甲霜灵·代森锰锌WG、58%甲霜灵·代森锰锌WP、80%代森锰锌WP及250 g/L嘧菌酯SC的防效,但防效明显下降,由2011年的92.58%～93.31%降至2016年的80.07%～80.82%。表明需要制定和实施抗药性治理对策,如限制山东和河北2省黄瓜的每个生长季节中687.5 g/L氟菌·霜霉威SC的使用不超过2次,而且要与不同作用机理的卵菌杀菌剂交替使用防治黄瓜霜霉病。     

几种药剂对马铃薯晚疫病田间防效及经济效益评价

本文评价分析了几种药剂对马铃薯晚疫病的田间防治效果和经济效益,结果表明,氟菌·霜霉威68.75%悬浮剂+丙森锌70%可湿性粉剂+赤·吲乙·芸薹0.136%可湿性粉剂组合处理的防效和经济收益最高,其次依次为氟啶胺50%悬浮剂+氰霜唑10%悬浮剂、霜脲·嘧菌酯60%水分散粒剂、枯草芽孢杆菌1 000亿芽孢/克可湿性粉剂。     

25%嘧菌酯悬浮剂防治马铃薯早疫病田间药效试验

25%嘧菌酯悬浮剂对马铃薯早疫病具有较好的防治效果。使用25%嘧菌酯悬浮剂(阿米西达)商品量18～36g/667m2,2次药后防效可达81.11%～84.75%,显著优于80%代森锰锌可湿性粉剂100g/667m2的防效。     

唑菌酯对8种蔬菜病原菌的生物活性

通过盆栽试验测定了唑菌酯对8种蔬菜病原菌的生物活性。结果表明,其对黄瓜灰霉病菌Botrytis cinerea、黄瓜霜霉病菌Pseudoperonospora cubensis、黄瓜炭疽病菌Colletotrichum orbiculare、黄瓜褐斑病菌Corynespora cassiicola和黄瓜黑星病菌Cladosporium cucumerinum具有较高活性,EC50值分别为 9.457、12.69、11.09、6.453和4.106 mg/L。 其中,在 250 mg/L 浓度下唑菌酯处理的防病效果与对照药剂嘧菌酯相当,防效大于75%。田间药效试验结果表明,20% 唑菌酯悬浮剂有效成分 80 mg/L 对黄瓜霜霉病的防效达 82.78%。     

不同种类杀菌剂对辣椒炭疽病的田间防效

为筛选出对辣椒炭疽病具有较好防效的杀菌剂,选用10种不同杀菌剂于2021年进行田间药效试验。结果表明：3次药后7 d, 32.5%苯醚甲环唑·嘧菌酯悬浮剂、50%咪鲜胺锰盐可湿性粉剂和43%氟吡菌酰胺·肟菌酯悬浮剂的防效分别为85.1%、82.7%和81.9%;25%吡唑醚菌酯乳油、24%烯肟菌胺·苯醚甲环唑悬浮剂和10%苯醚甲环唑水分散粒剂三者的防效在75.8%～77.8%之间;80%甲基硫菌灵水分散粒剂、22.5%啶氧菌酯悬浮剂和25%溴菌腈乳油等处理的防效在69.2%～74.6%之间;50%克菌丹可湿性粉剂的防效相对较差。32.5%苯醚甲环唑·嘧菌酯悬浮剂、50%咪鲜胺锰盐可湿性粉剂及43%氟吡菌酰胺·肟菌酯悬浮剂可作为福建地区防治辣椒炭疽病的较优选择。     

7种杀菌剂防治马铃薯晚疫病田间试验初报

本研究测定了7种杀菌剂对马铃薯晚疫病的田间防治效果。结果表明,2次药后7d,68. 75%氟吡菌胺·霜霉威悬浮剂和50%氟啶胺悬浮剂防效最好,分别达到81. 02%和80. 24%;其次为60%霜脲·嘧菌酯水分散粒剂防效达75. 26%;防效在60%～70%之间的有60%锰锌·氟吗啉可湿性粉剂、80%烯酰吗啉水分散粒剂、10%氰霜唑悬浮剂; 75%代森锰锌水分散粒剂防效相对最低。上述药剂对马铃薯晚疫病均有一定防效,建议在生产上轮换使用,其中代森锰锌为保护性杀菌剂,应在发病前或发病初期使用,其他药剂兼具保护和治疗效果。     

38％唑醚·戊唑醇悬浮剂对苹果树斑点落叶病的田间药效试验

本文为了探究38%唑醚·戊唑醇悬浮剂对苹果树斑点落叶病的防治效果和安全性,进行了田间药效试验。试验结果表明,38%唑醚·戊唑醇悬浮剂对斑点落叶病具有良好的防治效果,病情防效在90%以上,优于对照药剂25%吡唑醚菌酯微乳剂、80%代森锰锌可湿性粉剂、43%戊唑醇悬浮剂的病情防效,且差异极显著。     

6种杀菌剂对芦笋茎枯病的防治效果

芦笋茎枯病是芦笋生产上的毁灭性病害,近年来其发生程度有加重的趋势。为有效地防治该病,对6种杀菌剂进行了田间药效试验。结果表明:25%吡唑醚菌酯乳油的防效最好,对芦笋茎枯病防效为64.30%~74.85%;30%苯醚甲环唑乳油和20%嘧菌酯水分散粒剂次之,其防效分别为61.90%~72.66%和61.12~71.25%;30%醚菌酯悬浮剂的防治效果相对较好,防效为57.07%~67.37%。70%甲基硫菌灵可湿性粉剂和50%多菌灵可湿性粉剂的防效较差,其防效分别为24.48%~34.99%和22.37%~29.85%。25%吡唑醚菌酯乳油的增产率最高,有效成分用量300、400、500g/hm2的增产率分别为19.84%、22.08%、23.66%。30%苯醚甲环唑乳油次之,有效成分用量300、400、500g/hm2的增产率分别为19.32%、20.77%、22.14%。20%嘧菌酯水分散粒剂和30%醚菌酯悬浮剂的增产率相对较高,为15%~20%。对照药剂70%甲基硫菌灵可湿性粉剂和50%多菌灵可湿性粉剂的增产率均在10%左右。     

8种杀菌剂防治葡萄霜霉病田间药效试验

比较了8种杀菌剂对葡萄霜霉病的防治效果。结果表明:烯酰吗啉.甲霜灵30%水分散粒剂600倍液、烯酰吗啉40%悬浮剂600倍液、甲霜.锰锌72%水分散粒剂400倍液、嘧菌酯25%悬浮剂1 500倍液以及氯化十二烷基苄基铵10%水剂1 000倍液对葡萄霜霉病的防治效果良好,显著优于传统药剂三乙膦酸铝80%水分散粒剂500倍液、代森锰锌80%可湿性粉剂800倍液、丙森锌70%可湿性粉剂400倍液。其中,烯酰吗啉.甲霜灵30%水分散粒剂600倍液效果尤佳。     

Resistance to acylalanines in Pseudoperonospora cubensis1

Resistance to acylalanine fungicides in Pseudoperonospora cubensis, the downy mildew of cucurbits, is reviewed. Insensitive strains of the fungus predominated during the second year of metalaxyl application in cucumber glasshouses in Greece and Israel. Resistance was detected either on detached cucumber leaves floated on metalaxyl solutions or on potted plants treated (sprayed or drenched) with this fungicide. Metalaxyl-resistant strains of P. cubensis showed good pathogenicity and fitness, and competed favorably with the sensitive strains in the absence of the fungicide. A synergism between these two biotypes resulted in an increased virulence of the resistant forms on metalaxyl-treated plants. Metalaxyl-resistant strains of the pathogen exhibited cross resistance to other acylalanine fungicides. Strains resistant to acylalanines and to the chemically unrelated oomycete-fungicides fosetyl-Al and propamocarb were isolated in Israel, as well. In Greece, however, protective sprays with fosetyl-Al, cymoxanil and mancozeb gave good control of cucumber downy mildew when the pathogen was resistant to metalaxyl. P. cubensis is the first case of fungus which developed resistance to acylalanines in the field.     

生物源杀菌剂与化学杀菌剂协调防控黄瓜病害

本文研究枯草芽孢杆菌Bacillus subtilis BAB-1水剂、解淀粉芽孢杆菌B.amylololiquefaciens SAB-1水剂、大花旋覆花内酯乳油与化学杀菌剂交替或混合使用对温室黄瓜病害发展的影响.寿光试验包括以下处理:交替或混合喷施50%啶酰菌胺WG、68.75%氟吡菌胺·霜霉威SC的桶混液、60%唑醚·代森联WG、40%嘧霉胺SC、50%烯酰吗啉WP、10%苯醚甲环唑WG、69%烯酰·锰锌WP、68.75%噁唑·锰锌WG、52.5%噁唑·霜脲氰WG等不同作用机理和防治谱的化学杀菌剂;混施生防菌剂BAB-1水剂、SAB-1水剂及68.75%氟吡菌胺·霜霉威SC、50%烯酰吗啉WP、25%双炔酰菌胺SC、25%吡唑醚菌酯EC等对霜霉病特效化学杀菌剂;将不同化学杀菌剂桶混液与BAB-1水剂、SAB-1水剂和化学杀菌剂桶混液交替喷施.其对黄瓜霜霉病的防效分别为94.5%、92.3%和93.6%,对黄瓜白粉病分别为90.7%、89.9%和90.4%,对灰霉病的防效分别为69.3%、85.6%和85.7%,每种病害的病害发展曲线下面积(AUDPC)相当.在定州试验中,化学杀菌剂与SAB-1混施对白粉病的防效(84%)明显高于其与BAB-1混施的防效(72.8%),对灰霉病的防效(61.3%)明显低于后者的防效(95.1%),与SAB-1、BAB-1混施后对白粉病、灰霉病及霜霉病防效分别为90.2%、89.3%和92.6%.在保定郊区试验中,将大花旋覆花内酯乳油与化学杀菌剂及BAB-1水剂、SAB-1水剂交替喷施显著降低霜霉病、白粉病及灰霉病的严重度及AUDPC,对其防效分别为83.5%、87.4%和88.5%,AUDPC分别为219、352和249,延缓了3种黄瓜病害的发展.     

Occurrence and molecular characterization of azoxystrobin resistance in cucumber downy mildew in Shandong province of China

Cucumber downy mildew caused byPseudoperonospora cubensis (Berk. and Curt.) Rostov. limits crop production in Shandong Province of China. Since management of downy mildew is strongly dependent on fungicides, a rational design of control programs requires a good understanding of the fungicide resistance phenomenon in field populations of the pathogen. A total of 106 and 97 isolates ofP. cubensis were obtained in 2006 and 2007, respectively. The EC₅₀ values for the growth of all the 106 isolates collected in 2006 were 0.0063–0.0688μg ml⁻¹ (average: 0.0196±0.0048μg ml⁻¹) azoxystrobin and these were therefore considered sensitive isolates. However, 57 field isolates ofP. cubensis of the 97 collected in 2007 with EC₅₀ values that ranged from 0.609 to >51.2μg ml⁻¹ were considered resistant to azoxystrobin. Fragments of the fungicide-targeted mitochondrial cytochromeb gene from total pathogen DNA were amplified using polymerase chain reaction and their sequences analyzed to elucidate the molecular mechanism of resistance. A single point mutation (GGT to GCT) in the cytochromeb gene, resulting in substitution of glycine by alanine at position 143, was found in the three selected azoxystrobin-resistant isolates of downy mildew. This substitution in cytochromeb exhibited different resistance levels, with the resistance factor from 21.15 to greater than 2618.9. In addition, the different resistance levels seemed to appear within 1 year (between 2006 and 2007). Therefore, growers of Shandong Province in China now are faced with a challenge in managing the azoxystrobin resistance in cucumber downy mildew. http://www.phytoparasitica.org posting March 10, 2008.     

4种杀菌剂对紫皮石斛锈病的田间药效评价

针对紫皮石斛锈病。试验选用10%苯醚甲环唑WG,250 g/L嘧菌酯SC,29%吡萘·嘧菌酯SC,75%肟菌·戊唑醇WG 4种杀菌剂进行田间药效试验。结果表明:复配剂29%吡萘·嘧菌酯SC 600 mL/hm~2与75%肟菌·戊唑醇WG 300 g/hm~2,防效相当且显著高于其余两个施药处理,在第3次施药后7 d时达最高防效分别为87.70%和88.56%,鲜重折合产量比空白对照分别增产13.48%、13.22%,可在实际生产中交替使用。     

两种候选甲氧基丙烯酸酯类杀菌剂对黄瓜霜霉病的作用方式

20%唑胺菌酯EC、20%SYP-3998 SC是甲氧基丙烯酸酯类候选杀菌剂,为探索两药剂对黄瓜霜霉病的作用方式,采用盆栽植株喷雾-叶碟法、叶碟喷雾法、盆栽植株喷雾-叶碟法分别测定两药剂对黄瓜霜霉病的保护、治疗及持效期,并采用离体叶片法、叶碟法测定二者对黄瓜霜霉病的铲除作用.结果表明:20%唑胺菌酯EC和20%SYP-3998 SC具有良好的保护、治疗及铲除作用.两药剂的铲除作用表现在能抑制黄瓜霜霉病菌病斑扩展、孢子囊产生及孢子囊再侵染,与孢子囊混合接种能显著降低孢子囊的致病性.此外,20%唑胺茵酯EC和20%SYP-3998 SC具有7～10天的持效期;20%唑胺茵酯EC预防、治疗、铲除效果及持效性均优于20%SYP-3998 SC及对照药剂25%嘧菌酯SC.     

Control of cucumber downy mildew with novel fungicidal mixtures of Oxathiapiprolin

The efficacy of four oxathiapiprolin (OXPT)-based, novel fungicidal mixtures against downy mildew in cucumber caused by Pseudoperonospora cubensis was examined in growth chambers. OXPT+chlorothalonil (CHT) mixed at weight ratio of 1?+?66.7; OXPT+ azoxystrobin (AZ) 1?+?10.3; OXPT+mandipropamid (MPD) 1?+?8.3; and OXPT+mefenoxam (MFX) 1?+?3, were compared with each other and with individual components. Mixtures performed better than all fungicides alone except for oxathiapiprolin. Of the four mixtures, OXPT+MFX outperformed the other treatments with the highest preventive, curative, translaminar, root treatment and seed treatment efficacies. Deployment in the field of such mixtures with reduced doses of oxathiapiprolin may lower the selection pressure imposed on P. cubensis and delay the buildup of subpopulations resistant to oxathiapiprolin.     

霜脲氰与不同杀菌剂混配对两种霜霉病菌的增效作用

采用叶盘法（定量喷药）测定霜脲氰与不同杀菌剂混配对黄瓜和葡萄霜霉病菌抗甲霜灵菌株的增效作用,证实了霜脲氰加代森锰锌或二者再加恶霜灵以不同比率混配对黄瓜、葡萄霜霉病菌均明显增效,发现了霜脲氰与碱式硫酸铜1：8混配对黄瓜霜霉病菌增交,代森锰锌（1：8）或再加恶霜灵（1：8：1）对葡萄霜霉病菌的增效作用随着供试菌株对甲霜灵抗性水平的提高而增强。霜脲氰与代森锰锌1：7混配以保护、治疗、铲除方式处理黄瓜叶盘,对黄瓜霜霉病菌均表现增效。     

多黏类芽胞杆菌Paenibacillus polymyxa菌株P1防治黄瓜霜霉病的研究

通过离体叶片筛选法,得到1株对黄瓜霜霉病原菌有较强抑制作用的多黏类芽胞杆菌Paenibacillus polymyxa菌株P1。通过液体发酵和剂型处理,将P1制成含量2×10⁹ cfu/mL的悬浮剂分别进行室内和大田药效测试。室内药效试验结果表明,P1-SC悬浮剂对黄瓜霜霉病的防治效果与用药浓度呈正相关。当使用浓度为1.25×10⁷ cfu/mL时,P1悬浮剂对霜霉病的防治效果与化学农药250 g/L嘧菌酯SC的相似;当使用浓度为5.0×10⁷ cfu/mL时,防治效果显著大于嘧菌酯(P≤0.05)。2017年和2018年连续两年大田药效测试结果显示,经P1-SC处理(3000 mL/hm²)的黄瓜植株霜霉病病情指数(2.53,2.48)显著低于经250 g/L嘧菌酯SC(600 mL/hm²)处理的植株(4.33、6.22),防治效果(86.16%,89.90%)显著高于后者(76.34%、74.95%)(P≤0.05)。