10.5%高氯·啶虫脒乳油防治苹果黄蚜田间药效试验

10.5%高氯·啶虫脒乳油对苹果黄蚜具有优良的防治效果。使用10.5%高氯·啶虫脒乳油6000～8000倍液,在蚜虫发生期喷雾防治,施药后7d,防治效果可达90%以上。     

3种果树蚜虫有效防治药剂及剂量筛选

本文针对杏瘤蚜、梨二叉蚜和苹果黄蚜3种主要果树蚜虫,选取2种新型杀虫剂50%氟啶虫胺腈WG和240g/L螺虫乙酯SC以及2种常用杀虫剂70%吡虫啉WG和20%啶虫脒WG,采用常规喷雾法比较了不同药剂、不同用药剂量的田间防治效果和持效性。结果表明,在杏瘤蚜和梨二叉蚜发生期,使用50%氟啶虫胺腈WG 41.67、55.56、83.33mg/L,240g/L螺虫乙酯SC 28.00、56.00mg/L,70%吡虫啉WG 35.00、70.00mg/L和20%啶虫脒WG 33.33、50.00mg/L喷雾处理,药后7、14和21d防治效果均在86.21%以上,具有良好的防治效果和持效性。在苹果黄蚜发生期,70%吡虫啉WG和20%啶虫脒WG药后7d防治效果较好,14d和21d的防治效果远低于7d的防效,持效性较差;50%氟啶虫胺腈WG 41.67 mg/L处理与70%吡虫啉WG和20%啶虫脒WG表现相似;而50%氟啶虫胺腈WG 55.56、83.33mg/L和240g/L螺虫乙酯SC 28.00、56.00mg/L在7、14和21d防治效果分别在97.24%、92.44%和75.42%以上,表现良好的防治效果和持效性。综合分析认为,杏瘤蚜和梨二叉蚜对4种药剂均具有较高的敏感性,而70%吡虫啉WG和20%啶虫脒WG在田间对苹果黄蚜已表现出防效下降和持效期缩短的现象。据此推荐在杏瘤蚜和梨二叉蚜成蚜发生期,使用50%氟啶虫胺腈WG、240g/L螺虫乙酯SC、70%吡虫啉WG、20%啶虫脒WG,分别以有效成分用量41.67、28.00、35.00、33.33mg/L进行常规喷雾处理。在苹果黄蚜成蚜发生期,使用50%氟啶虫胺腈WG 55.56mg/L和240g/L螺虫乙酯SC 28.00mg/L进行常规喷雾处理,可有效控制3种蚜虫为害。     

6种杀虫剂防治苹果黄蚜田间药效试验

通过6种杀虫剂对苹果黄蚜田间药效试验结果表明:20%丁硫克百威乳油对苹果黄蚜的防治效果最好,其次为5%啶虫脒可湿性粉剂、10%氯噻啉可湿性粉剂、40%毒死蜱乳油、25%吡虫啉可湿性粉剂,2.5%溴氰菊酯乳油效果最差。     

3种农药对莲藕莲缢管蚜的杀虫活性和安全性

为筛选防治莲藕莲缢管蚜的理想药剂,比较研究了吡虫啉、啶虫脒、吡蚜酮的杀虫活性、田间防效、作物安全性和残留。结果表明,啶虫脒对莲缢管蚜3日龄蚜虫的LC50为0.09mg/L,毒力显著高于吡虫啉和吡蚜酮(LC50值分别为0.26mg/L和1.0mg/L)。湖南、湖北、浙江、福建和山东田间试验结果表明,吡虫啉、啶虫脒和吡蚜酮在15g/hm2以上有效使用剂量时,药后7d对莲藕莲缢管蚜的防治效果均在90%以上。10%吡虫啉可湿性粉剂、5%啶虫脒乳油、25%吡蚜酮可湿性粉剂在稀释250倍及以下剂量时拌种或茎叶喷雾对莲藕植株生长均无药害。残留试验结果表明,吡虫啉在莲叶上的半衰期为2.5~5.9d;啶虫脒在莲叶上的半衰期为7.4~9.5d;吡蚜酮在莲叶上的半衰期为0.8~1.3d。吡虫啉、啶虫脒和吡蚜酮防治莲藕莲缢管蚜安全、高效。     

吡蚜酮对小麦穗期灰飞虱与麦蚜的防治效果

吡蚜酮(pymetrozine)对小麦穗期灰飞虱的防治效果优于吡虫啉、啶虫脒和氰戊菊酯,对麦穗蚜的防治效果接近于以上各药剂。在小麦扬花初期预防灰飞虱和麦蚜时,667 m2分别用25%吡蚜酮可湿性粉剂15 g和25 g,用药后第30天的防治效果在90%左右;在小麦灌浆期防治灰飞虱与麦蚜时,667 m2用25%吡蚜酮可湿性粉剂15~20 g,用药后5~10 d的防治效果稳定在90%以上。     

防治特色小宗作物沾化冬枣绿盲蝽试验研究

为筛选防治冬枣绿盲蝽的药剂,采用浸叶法及喷雾相结合的方法,对吡虫啉、啶虫脒2种药剂进行了室内活性测定和田间药效试验。结果表明,吡虫啉、啶虫脒对绿盲蝽的室内活性基本相当,LC_(50)分别为8.52、9.84 mg/L,对照药剂氟氯氰菊酯活性最差。田间试验剂量下,各药剂对绿盲蝽均有较好的防治效果,70%吡虫啉水分散粒剂(70.0～93.3mg a.i./kg)和40%啶虫脒水分散粒剂(50.0～80.0mg a.i./kg)防效相近,且防治效果与浓度呈正相关。20%吡虫啉微乳剂80.0 mg a.i./kg与70%吡虫啉水分散粒剂82.4 mg a.i./kg防效间无明显区别。     

露地和网棚蔬菜蚜虫的药剂防治

以黄瓜、辣椒和茄子3种蔬菜为靶标试验作物,在露地和网棚两种栽培方式下,研究4.5%高效氯氰菊酯乳油、70%啶虫脒乳油、10%高效氯氟氰菊酯乳油及5%高氯·啶虫脒乳油对蔬菜蚜虫的防治效果。结果表明,药后3～6d,在同一栽培方式下,4种杀虫剂防治蚜虫效果由低到高依次为4.5%高效氯氰菊酯乳油、70%啶虫脒乳油、10%高效氯氟氰菊酯乳油、5%高氯·啶虫脒乳油。同种药剂在网棚的杀虫效果高于露地。药后13 d,4种杀虫剂防效高低排序未发生变化。但同种药剂露地杀虫效果已高于网棚。     

陕西关中地区小麦穗期蚜虫发生及抗性治理对策

自20世纪90年代初期以来,陕西关中地区小麦穗期蚜虫种群数量呈逐年上升趋势,发生高峰期在5月中、下旬,从小麦抽穗到成熟,受蚜虫为害,千粒重降低3.2%～47.0%,减产10%～15%,严重田块产量损失达40%以上。麦穗蚜对氧乐果已达中抗水平,LC50为122.55;对吡虫啉、抗蚜威也产生了明显的抗性,LC50分别为53.78和30.96;对啶虫脒、阿维虫清的抗性较低。依据麦穗蚜防治现状及抗药性,结合小麦穗期既是麦蚜的主要为害期,也是麦田天敌大量繁殖期的实际,从保护麦田生态系统,延缓麦蚜抗药性角度出发,提出了选择使用吡虫啉、抗蚜威、啶虫脒等新型高效、低毒杀虫剂,重视保护天敌,构建麦田半自控生态系统等麦穗蚜综合防治对策。     

农用有机硅助剂＋啶虫脒防治柑桔蚜虫试验

农用有机硅助剂功倍和丝润加入到农药3％啶虫脒后对柑桔蚜虫有很好的防治效果,药后7d平均防效达96．1％～99．5％,节约用水50％～70％,减少农药啶虫脒用量1-10g／667m^2．次,节约防治成本1．5～6．3元／667m^2次。利用农用有机硅＋农药啶虫脒防治柑桔蚜虫,能够节约用水,减少农药使用量,降低农药残留,符合环保要求。     

3种新型杀虫剂对苹果黄蚜的毒力效果评价

采用浸叶法在室内测定了3种药剂对苹果黄蚜的毒力,并在田间进行了防治试验。室内毒力测定结果表明:供试3种新型药剂中,双丙环虫酯和氟吡呋喃酮对苹果黄蚜的毒力较高,LC₅₀分别为3.16 mg/L和23.58 mg/L,三氟苯嘧啶毒力较低,LC₅₀为329.92 mg/L。田间试验结果表明:3种药剂对苹果黄蚜均有较好的速效性和持效性。17%氟吡呋喃酮可溶液剂和10%三氟苯嘧啶悬浮剂各处理3～7 d防效为82.19%～93.45%,药后30 d防效达到78.91%～87.92%;50 g/L双丙环虫酯可分散液剂2.5 mg/kg和4.2 mg/kg处理药后3～7 d防效为94.64%～97.04%,药后21 d防效仍可达88%以上。因此,3种新型药剂均可以用于防治苹果黄蚜,田间使用时推荐有效成分用量为双丙环虫酯2.5～4.2 mg/kg,氟吡呋喃酮113～170 mg/kg,三氟苯嘧啶28～80 mg/kg。     

Localization of metabolic sites of action of herbicides

Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate ¹⁴C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides.     

福寿螺配偶个体大小选择性初步观察

通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。     

青稞种子带菌检测及杀菌剂消毒处理效果

为了研究青稞种子外部和内部携带真菌情况,比较不同杀菌剂对青稞种子的带菌消毒效果和对幼苗生长的影响,为青稞种子播前包衣处理和种传真菌病害防控提供依据,采用离体平皿法对云南迪庆‘云青1号’、‘云青2号’和‘短白青稞’3个主栽品种进行带菌检测,并对种子进行拌种或浸种处理测定6种杀菌剂对种子消毒效果,分析杀菌剂对种子发芽和幼苗生长的影响。结果表明:供试青稞种子表面携带的优势菌群为青霉(Penicilliumspp.)、镰刀菌(Fusariumspp.);种子内部寄藏的真菌主要为镰刀菌、核腔菌(Pyrenophoraspp.)、附球菌(Epicoccumspp.)、丝核菌(Rhizoctoniaspp.)、链格孢(Alternariaspp.)和木霉(Trichoderma spp.)。青稞不同品种的种子表面及内部携带的真菌种类差异较大。致病性测定表明,镰刀菌对种子萌发和幼苗生长影响最大,后期出现幼苗坏死现象。45%咪鲜胺EW、75%百菌清WP、50%福美双WP对青稞种子携带真菌均有显著抑制作用和消毒效果,50%福美双WP消毒效果最优,达100%;45%咪鲜胺EW、75%百菌清WP、50%福美双WP处理对青稞种子发芽和幼苗生长均无显著影响。     

Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato

The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere.     

厚朴病虫害种类的初步调查

采用标准地法和线路调查法,对湖北恩施市新塘乡双河厚朴基地的厚朴病虫害进行了系统调查,记录主要虫害13种,其中叶部害虫9种,枝干害虫2种,根部害虫2种。厚朴主要病害5种。藤壶蚧、厚朴枝角叶蜂和厚朴新丽斑蚜为湖北省首次报道,小绿叶蝉为厚朴新寄主记录种。同时记录了藤壶蚧的天敌6种,其中寄生小蜂2种,瓢虫4种;厚朴新丽斑蚜的天敌昆虫8种。对藤壶蚧、厚朴枝角叶蜂和厚朴苗木根腐病等重要病虫害的发生规律进行了初步调查,同时提出了防治建议。     

黑麦草属DNA条形码鉴定技术研究

以毒麦、田毒麦、多花黑麦草、多年生黑麦草、硬直黑麦草、高羊茅与狗牙根等禾本科的7种植物为材料,拟采用 DNA 测序、特异性位点比对、种间遗传距离测定、建立系统树等分析候选 DNA 条形码 psbA-trnH 鉴别黑麦草属常见植物的能力。实验结果表明,以 psbA-trnH 为 DNA 条形码时,建立的系统发育树能较好区分毒麦和田毒麦与其他几种植物。psbA-trnH 序列可以作为黑麦草属植物的潜在条形码。     

棉花黄萎病菌致病型的AFLP分析

 选用41个棉花黄萎病菌(Verticillium dahliae)代表菌系,在温室条件下,对4个棉花品种鄂荆1号(感)、中棉所12(耐)、文-5(抗)和唐棉2号(抗)进行致病性测定,结果可将供试菌系分为落叶型与非落叶型2类。选取8对AFLP引物PCR扩增的结果中,统计带型稳定、清晰且有多态性的条带,共169条作系统聚类分析,将上述菌系分为2大类,第一类为非落叶型菌系,包括10个非落叶型菌系和1个过渡菌系;第二类为30个落叶型菌系。根据聚类分析建立树状图,发现菌系与地理来源存在一定的相关性,而依据菌系致病力强弱分类则相关关系不大。选用25对EcoRⅠ和MseⅠ引物组合,对供试的41个V.dahliae进行AFLP扩增,筛选到2对引物E64(GACTGCGTACCAATTCGAC)、M53(GATGAGTCCTGAGTAACCG)和E49(GACTGCGTACCAATTCCAG)、M65(GAT-GAGTCCTGAGTAAGAG),能分别扩增出433bp和110bp2条仅为V.dahliae非落叶型菌系独有的特异片段,可将落叶型与非落叶型菌系分开,这2条特异片段被命名为EM₄₃₃和EM₁₁₀。     

Mode of action of etoxazole

The mode of action of the 2,4-diphenyl-1,3-oxazoline acaricide/insecticide etoxazole has been argued to be moulting inhibition, but experimental results supporting this hypothesis are lacking. This study investigated the effect of etoxazole on chitin biosynthesis in the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Etoxazole induced moulting defects in fall armyworm larvae similar, if not identical, to those caused by benzoylphenylureas, a well-known class of insecticidal chitin biosynthesis inhibitors. Furthermore, in contrast to untreated larvae, the chitin content in the integuments of larvae several days after treatment did not differ from that in freshly ecdysed individuals, thus suggesting strong chitin biosynthesis inhibition in vivo. A more detailed investigation of the inhibitory potential by incubating cultured integument pieces from larvae of S. frugiperda with [14C]N-acetyl-D-glucosamine, a radiolabelled chitin precursor, revealed I50 values of 2.95 and 0.071 microM for etoxazole and triflumuron respectively. The incorporation of radiolabel into potassium hydroxide-resistant material was inhibited by etoxazole in a dose-dependent manner. Based on these results, it is concluded that the acaricidal and insecticidal mode of action of etoxazole is chitin biosynthesis inhibition.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.