甲霜灵·刺复配剂对棉疫病菌的联合毒力

在实验室条件下，测定了甲霜灵和霜霉威复配剂对棉疫病菌（Phytophthora boehmeriae）的联合毒力。结果表明，复配剂MPA、MPB、MPC对棉疫病菌的DC5。分别为0．0555,0．1044μg／mL和0．0845μg／mL，对照单剂甲霜灵和霜霉威对棉疫病菌的EC50分别为0．0391μg／mL和10．6183μg／mL；联合毒力分析表明，甲霜灵和霜霉威按1：1．5复配有增效作用，按1：1和1．5：1复配有相减作用。     

霜霉威吡虫啉腐霉利在结球生菜上的消解动态及相关因子的影响

通过开展结球生菜生产中所用主要农药--霜霉威、吡虫啉、腐霉利的消解规律研究,探讨生菜农药消解与农药种类、浓度及外部因子的关系,为结球生菜生产过程中的安全管理提供参考依据。以目前我国生产上主要使用的结球生菜品种--＂皇帝＂为材料,2007年春季露地种植,按霜霉威、腐霉利、吡虫啉最大推荐用量（计算浓度分别为1203.3、500.0、40.0mg·kg-1）和最大推荐用量的2倍（计算浓度分别为2406.6、1000.0、80.0mg·kg-1）两个农药剂量处理,分别于6月6日施药后当日、2、6、9d取样测定农药残留含量,并记录环境因子温度、光照的变化。结果表明,不论是按最大推荐用量还是最大推荐用量2倍喷施,吡虫啉、霜霉威、腐霉利在生菜上均表现为起始和最后阶段消解快、中间阶段消解平缓的特点;按日本肯定列表制度对生菜吡虫啉、霜霉威和腐霉利最大残留限量（分别为5.0、10.0和5.0mg·kg-1）要求,对于吡虫啉,即使按最大推荐用量2倍喷施,其喷施8h后的残留量仅为1.5mg·kg-1,说明春季露地生菜上喷施吡虫啉的安全性较高;对于霜霉威,按最大推荐用量喷施,施药6d后的残留量为10.7mg·kg-1,接近肯定列表制度的要求,施药9d后的残留量降至8．4mg·kg-1,表明霜霉威自喷药至采收的间隔期应至少在7d以上才可能是安全的;对于腐霉利,到试验结束时,不论何种喷施浓度,其残留量均超过5．0mg·kg-1的要求,其使用安全性需要引起重视。在影响吡虫啉、霜霉威、腐霉利在生菜上消解的因素方面,统计分析表明,外部因子（时间、温度、光照）对3种农药消解具有显著作用（P〈0．05）,农药种类在对其消解率影响方面达到极显著差异（P〈0．01）,其中吡虫啉最易消解,其次为霜霉威,腐霉利消解最慢,但3种农药喷施浓度的高低对各自消解率均无显著影响（P〉0．05）。     

外源褪黑素降低黄瓜体内霜霉威残留的生理生化分析

为探究褪黑素(melatonin,Mel)对黄瓜体内农药降解中的调控作用,以黄瓜‘Y3F604’为材料,以氨基甲酯类农药霜霉威(C₉H₂₀N₂O₂)为处理试剂,采用灌根的方法研究外源施用1 mmol/L Mel对黄瓜体内霜霉威残留的影响,同时探究O₂^-·、H₂O₂、MDA、GSH和GSSG含量以及抗氧化酶和解毒酶的变化情况。结果表明,外源1 mmol/L的Mel处理显著降低了霜霉威处理48 h后黄瓜体内的霜霉威残留量。在霜霉威胁迫下,黄瓜叶片中O₂^-·、H₂O₂和MDA的含量明显增加,而外源Mel处理能够有效抑制霜霉威胁迫下黄瓜体内的O₂^-·、H₂O₂和MDA积累。与对照相比,外源Mel处理显著提高了霜霉威胁迫下SOD、CAT、POD、APX、GPX等抗氧化物酶活性,进一步促进GSH含量和总谷胱甘肽含量的增加,提高GSH/GSSG、GST与GR解毒酶活性。因此,外源施用Mel可提高黄瓜在霜霉威胁迫下的抗氧化能力和解毒能力,从而加速黄瓜体内霜霉威的代谢,是促进蔬菜残留农药降解的新途径。     

Study on Relationship Between Cucumber Germplasm and Propamocarb Residue Using Subjective Rating Technique

Propamocarb(PM)residue in cucumber(Cucumis sativus L.)receives little attention.As is well known to all,high PM residue of cucumber could lead to increase in the violation rates of maximum residue limits and ultimately cause harm to human health.Knowledge of PM residue could help cucumber breeders in developing cultivars with low PM residue and improving cucumber quality.In this study,32 representative cucumber accessions(26 breeding lines and six cultivars)from different regions of China were evaluated for their PM residue in fruit and leaf to provide meaning to the subjective rating,which was highly correlated with PM residual content of fruit(r=0.97)and leaf(r=0.94).In addition,PM residual content of North China ecotype was the highest and Pickling ecotype was the lowest in fruit and leaf of cucumber.The leaf had significantly higher(P<0.01)PM residual content than the fruit,and poor correlation between leaf and fruit was represented.This study verified PM residual relationship between fruit and leaf,and laid the foundation for further identification of germplasm resources and breeding of new varieties for low PM residue of cucumber.     

Occurrence of metalaxyl-resistant ttrains of Phytophthora infestans in Dutch potato fields

Samenvatting In de zomer van 1980 gaf in een aantal gevallen het systemische fungicide metalaxyl een zeer onvoldoende werking te zien tegen de aardappelziekte.Phytophthora infestans-isolaten die uit de desbetreffende percelen werden verkregen vertoonden in een drijftoets een zeer geringe gevoeligheid voor het fungicide in vergelijking met isolaten uit percelen waar gebruik werd gemaakt van maneb/fentin-acetaat combinaties en waarin nagenoeg geen aantasting voorkwam.De oorzaak van de onvoldoende werking van metalaxyl moet worden gezocht in het ontstaan van metalaxyl-resistente stammen in de populatie, die als gevolg van de voor de aardappelziekte geschikte weersomstandigheden en de veelvuldige toepassing van alleen metalaxyl zich ongebreideld konden vermenigvuldigen.Metalaxyl-resistentie kwam voor in verschillende fysio's. Dit wijst erop dat de resistentie op meerdere plaatsen is ontstaan. Opmerkelijk was dat éé van de resistente fysio's nooit eerder in Nederland was geisoleerd.     

霜霉威在花椰菜上的消解动态及最终残留研究

【目的】研究霜霉威在花椰菜上的消解动态及最终残留量,评价其在花椰菜上使用的安全性,为霜霉威在花椰菜上的科学合理使用及限量标准研究提供依据。【方法】建立测定花椰菜中霜霉威残留量的色谱-质谱法;按照农药残留试验准则,于2013和2014年在河北保定、陕西西安、四川广元进行霜霉威在花椰菜上残留的田间试验,采集样品并经乙酸乙酯匀浆提取和液-液萃取净化,减压浓缩定容后,采用液相色谱-质谱法进行霜霉威残留量检测。【结果】霜霉威在花椰菜植株及可食用部分中的添加回收率分别为85.9%~104.5%,87.5%~101.5%,其在花椰菜植株及可食用部分中的最低检出含量均为0.05mg/kg,最低检出量均为0.25ng。2013和2014年,霜霉威在花椰菜植株中的原始残留量分别为4.68和1.36mg/kg,半衰期分别为6.0和5.3d,属于易降解农药。2013和2014年最终残留试验结果表明,于最后一次施药后的5,7和10d,霜霉威在花椰菜可食用部分中的最终残留量最大值分别为0.94和0.76,0.62和0.55,0.52和0.36mg/kg。【结论】成功建立了检测农产品中残留的霜霉威的液相色谱-质谱法;霜霉威在花椰菜上的最大残留量均低于欧盟的标准,属于易降解农药,在花椰菜上使用安全。     

68．75％氟吡菌胺·霜霉威不同施药时期对辣椒疫病防效的影响

[目的]确定68．75％氟吡菌胺·霜霉威SC在不同时期施药对辣椒疫病的防治效果及安全性。[方法]以中椒7号为供试材料,辣椒疫病为防治对象,研究几种药剂不同施药时期施用对辣椒疫病防治效果。[结果]68．75％氟吡菌胺·霜霉威SC对辣椒疫病有很好的防治效果,在试验剂量内时辣椒安全无药害。药剂施药时期不同,对辣椒疫病防治效果不同,最佳途径是苗期用药和移栽后田间喷雾相结合。推荐苗期使用72．2％霜霉威盐酸盐AS43320g／hm^2苗床泼浇,或移栽前用68．75％氟吡菌胺·霜霉威SC17187．5g/hm^2灌根或泼浇;移栽后大田发病初期用68．75％氟吡菌胺·霜霉威SC773．44—1031．25g/hm^2喷淋茎基部或喷雾,间隔7d施药一次,可连喷2～3次。[结论]该研究为辣椒疫病的防治提供了科学依据。     

霜霉威吡虫啉腐霉利在结球生菜上的消解动态及相关因子的影响

通过开展结球生菜生产中所用主要农药——霜霉威、吡虫啉、腐霉利的消解规律研究,探讨生菜农药消解与农药种类、浓度及外部因子的关系,为结球生菜生产过程中的安全管理提供参考依据。以目前我国生产上主要使用的结球生菜品种——皇帝为材料,2007年春季露地种植,按霜霉威、腐霉利、吡虫啉最大推荐用量(计算浓度分别为1203.3、500.0、40.0mg·kg-1)和最大推荐用量的2倍(计算浓度分别为2406.6、1000.0、80.0mg·kg-1)两个农药剂量处理,分别于6月6日施药后当日、2、6、9d取样测定农药残留含量,并记录环境因子温度、光照的变化。结果表明,不论是按最大推荐用量还是最大推荐用量2倍喷施,吡虫啉、霜霉威、腐霉利在生菜上均表现为起始和最后阶段消解快、中间阶段消解平缓的特点;按日本肯定列表制度对生菜吡虫啉、霜霉威和腐霉利最大残留限量(分别为5.0、10.0和5.0mg·kg-1)要求,对于吡虫啉,即使按最大推荐用量2倍喷施,其喷施8h后的残留量仅为1.5mg·kg-1,说明春季露地生菜上喷施吡虫啉的安全性较高;对于霜霉威,按最大推荐用量喷施,施药6d后的残留量为10.7mg·kg-1,接近肯定列表制度的要...     

Compatible Biological and Chemical Control Systems for Rhizoctonia solani in Potato

A series of chemical and biological control agents were tested for compatibility with the Rhizoctonia-specific biocontrol fungus Verticillium biguttatum aimed at designing novel control strategies for black scurf (Rhizoctonia solani) and other tuber diseases in potato. The efficacy of chemicals, alone and in combination with V. biguttatum was tested in in vitro assays on nutrient agar plates, in bio-assays with minitubers and in the field. Generally, there were both antagonistic, neutral and additive interactions with V. biguttatum among the combinations tested; there were no indications for synergistic interactions. Broad-spectrum fungicides (azoxystrobin, chlorothalonil, thiabendazole) were fungitoxic to V. biguttatum as shown in in vitro assays, and hampered black scurf control by V. biguttatum in bio-assays. Oomycete-specific chemicals (cymoxanil and propamocarb) and various biocontrol strains (Gliocladium spp., Pseudomonas spp. and Trichoderma spp.) did not interfere with the growth of V. biguttatum on agar nutrient plates and did not affect black scurf control by V. biguttatum in co-applied treatments in the minituber bio-assay. Rhizoctonia-specific (pencycuron, flutalonil) fungicides co-applied with V. biguttatum showed additive effects on black scurf control. When combinations of V. biguttatum and cymoxanil or propamocarb were applied to immature potato tubers at green crop lifting, a reduction of both black scurf and Pythium- or Phytophthora-incited tuber rot was observed at harvest. In conclusion, the biocontrol fungus V. biguttatum is compatible with selected chemical control systems and may improve control efficacy in combination with Rhizoctonia-specific fungicides or may extend control spectrum in combination with Oomycete-specific fungicides.