增效剂对常用烟碱类杀虫剂防治棉蚜的减量增效作用

[目的]研究添加增效剂对常用烟碱类杀虫剂吡虫啉和噻虫嗪防治棉蚜的增效作用,为增效剂和杀虫剂的科学高效利用提供数据基础.[方法]采用田间小区喷雾试验,测定增效剂的适宜用量,对比分析杀虫剂田间常规用量减少10％、20％、30％后添加增效剂对棉蚜的防效.[结果]0.15％Fieldor Max EC对烟碱类杀虫剂吡虫啉和噻虫...     

上海地区小菜蛾的抗药性及增效剂的作用

用FAO推荐的点滴法测定了上海、广州和江西等地小菜蛾(Plutella xylostetla L.)的抗药性。测定结果表明,上海和广州的小菜蛾(DBM)对现有的各类杀虫剂,如DDT、有机磷、氨基甲酸酯和拟除虫菊酯都发生了抗药性,其中以拟除虫菊酯的抗药性尤为突出,如溴氰菊酯(均>10414倍)、氰戊菊酯(2103和>3569倍)和氯菊酯(245和1533倍)。用浸渍法监测了上海地区小菜蛾对有机磷(1979-1987年)和拟除虫菊酯(1981-1987年)的扰药性。上海地区的DBM对敌敌畏、乐果和乙酰甲胺磷的抗性分别为8.1、10.1和16.6倍;从1981-1986年,DBM对氰戊菊酯,溴氰菊酯,氯菊酯、氯氰菊酯和氟氰戊菊酯的抗性分别为406.4、66.5、38.2、78.5和313.5倍,在1990年它们的抗性都有不同程度降低。各种解毒酶抑制剂TBPT,PB,TPP,DEM和DMC的活体测定表明,DBM的抗性涉及多功能氧化酶(MFO)、谷胱甘肽转移酶和酯酶,可能还涉及神经敏感度降低。     

助剂对精喹禾灵防治棉田杂草的减量增效作用

【目的】研究添加助剂对精喹禾灵EC防除棉田禾本科杂草的增效作用,为除草剂减量施用和科学除草提供数据基础。【方法】通过温室盆栽和田间小区试验,在除草剂常规用量、减量20%和减量40%基础上添加助剂,比较精喹禾灵EC对马唐、牛筋草等禾本科杂草的防除效果。【结果】盆栽试验中,在推荐的常量用药水平下添加助剂Foxy SG和Fieldor Max EC,精喹禾灵EC对马唐和牛筋草2种禾本科杂草防效提高1.75%~5.78%,精喹禾灵EC减量20%和40%,2种助剂对防效的增效幅度分别为7.95%~10.54%和21.62%~41.63%,Fieldor Max EC的增效作用显著优于Foxy SG,精喹禾灵EC减量40%后添加Fieldor Max EC对禾本科杂草的防效与常量用药防效无显著差异;田间试验中,2种助剂对精喹禾灵EC的减量增效作用与盆栽试验结果相符,常量用药水平下添加Foxy SG和Fieldor Max EC,精喹禾灵EC对禾本科杂草株防效和鲜重防效提高0.83%~4.19%,精喹禾灵EC减量20%和40%,2种助剂对防效的增效幅度分别为1.08%~8.68%和12.06%~37.74%,Fieldor Max EC的增效作用显著优于Foxy SG,精喹禾灵EC减量40%后添加Fieldor Max EC对禾本科杂草的株防效与常量用药株防效无显著差异。【结论】Foxy SG和Fieldor Max EC 2种助剂,对棉田常用的选择性除草剂精喹禾灵EC除草活性有明显提高,减少除草剂使用量后加入助剂可解决防效降低问题,除草剂使用过程中加入高效助剂是实现除草剂减量增效的有效途径。     

Interaction between Plant Nutrients: II. Effect of Chloride on Activities of Cations in Soil Solution and on Nutrient Uptake by Plants

Abstract

In soil solutions the sum of cations is equivalent to that of anions. Anions are soluble or precipitated as less soluble salts. Therefore, the sum of soluble anions are responsible for the sum of cations in the soil solution. Soluble nitrate anions are unstable as they immobilize in biological materials. Hydrogen carbonate is excreted from plant roots and decomposes into carbon dioxide and carbonate. Carbonate reacts with hydrogen ions and forms complexes and ion pairs with calcium ions. Sulphate and chloride are more stable in the soil solution as anions.

Chloride ions were found to increase the activity of cations in the soil solution and to increase uptake of cations through the entire growth period. Increased absorption of cations increased yield. In temperate climate regions the surplus of chloride leaches from the root zone during winter.     

苏脲1号对胺甲萘与对硫磷的增效作用

以抗性棉铃虫（ＨｅｌｉｃｏｖｅｒｐａａｒｍｉｇｅｒａＨ．）为对象，研究了几丁质合成抑制剂——苏脲１号与对硫磷、胺甲萘的混合作用及其增效机制。结果表明，药剂混用后，对总酯酶及乙酰胆碱酯酶（ＡｃｈＥ）活性的抑制程度均有明显增强。混剂在对棉铃虫体内解毒酶系以及靶标酶活性的抑制水平上的增强，可能是这两种杀虫剂混用后表现增效作用的重要因素。     

Resistance to spinosad in the western flower thrips, Frankliniella occidentalis (Pergande), in greenhouses of south-eastern Spain

Susceptibility to spinosad of western flower thrips (WFT), Frankliniella occidentalis (Pergande), from south-eastern Spain was determined. LC(50) values of the field populations without previous exposure to spinosad collected in Murcia in 2001 and 2002 ranged from 0.005 to 0.077 mg L(-1). The populations collected in Almeria in 2003 in greenhouses were resistant to spinosad (LC(50) > 54 mg L(-1)) compared with the authors' highly susceptible laboratory strain. The highly sensitive laboratory strain leads to very high resistance ratios for the field populations (>13 500), but these ratios do not necessarily mean resistance problems and control failures (spinosad field rate 90-120 mg L(-1)). The populations collected in Murcia from some greenhouses in 2004 were also resistant to spinosad (RF > 3682). Spinosad overuse, with more than ten applications per crop, produced these resistant populations in some greenhouses. Spinosad showed no cross-resistance to acrinathrin, formetanate or methiocarb in laboratory strains selected for resistance towards each insecticide. Correlation analysis indicated no cross-resistance among spinosad and the other three insecticides in 13 field populations and in nine laboratory strains. The synergists piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF) and diethyl maleate (DEM) did not enhance the toxicity of spinosad to the resistant strains, indicating that metabolic-mediated detoxification was not responsible for the spinosad resistance. These findings suggest that rotation with spinosad may be an effective resistance management strategy.     

生防菌防治黄瓜枯萎病的协同作用研究

采用传统方法统计可培养微生物的数量,采用常规方法测定土壤酶活、统计黄瓜形态指标和发病株数,探讨不同生防菌株枯草芽孢杆菌D、放线菌317和木霉菌联合防治黄瓜枯萎病是否具有协同增效作用。结果表明:3株菌株联合优于单一菌株和2株菌株联合,其协同增效作用最佳。与对照相比,3株菌株联合处理根际土壤中细菌、放线菌、真菌数量的接种增率分别为50.57%、110.98%和13.48%,菌群结构开始由真菌型向细菌型过渡;土壤中性磷酸酶、蔗糖酶、过氧化氢酶和脲酶活性增长率分别为244.90%、7.17%、2.90%和31.01%;黄瓜株高、茎粗、叶片数和干物质重量的增长率分别为33.92%、35.48%、34.43%和79.13%;防治效果最佳达52%。与其它处理相比,3株菌株联合处理对根际土壤微生物数量、菌群结构、过氧化氢酶、黄瓜的形态指标和枯萎病的防治效果具有明显的协同增效作用,其在生产中具有较大的应用潜力。     

苏云金杆菌与高效氯氰菊酯对美国白蛾的协同作用

为了明确苏云金杆菌 Bacillus thuringiensis (Bt)和高效氯氰菊酯的协同作用,采用Bt预处理及直接混用2种方式施药,室内饲毒法测定了2种药剂对美国白蛾 Hyphantria cunea (Drury) 2龄幼虫的活性,同时研究了高效氯氰菊酯对Bt生长曲线的影响。结果表明:试虫先用每mL含1×106个孢子的Bt S19菌悬液预处理,1 d后再用系列浓度的高效氯氰菊酯处理,其48 h的LC50值为0.76 mg/L,而未经预处理,仅用高效氯氰菊酯处理48 h的LC50值为1.28 mg/L;2种处理在高效氯氰菊酯质量浓度为2.25 mg/L时对试虫的半致死时间(LT50值)分别为9.2 h和34.7 h,两者间增效作用明显。对于直接混用,采用1×106个/mL的Bt S19与6 mg /L的高效氯氰菊酯混剂处理,增效作用明显,72 h的共毒系数为122.5,此后再增加高效氯氰菊酯的浓度则表现出轻微的拮抗作用。高效氯氰菊酯处理可使Bt生长对数期延迟,且浓度越高影响越大,说明高效氯氰菊酯可影响Bt芽孢萌发,使菌体增殖延迟。研究表明,先用Bt预处理后再使用高效氯氰菊酯对美国白蛾的作用效果优于二者直接混用。     

10%甲氰·阿维乳油配方的筛选及其对朱砂叶螨的联合作用

通过对助剂和配方的筛选,确定10%甲氰·阿维乳油的溶剂为20∶1(质量比,下同)的二甲苯与乙酸乙酯混合溶液,乳化剂为30∶1的QR-9与QR-11混合物,其添加量为60 mg/g。采用玻片浸渍法测定9种不同配比复配剂对朱砂叶螨Tetranychus cinnabarinus (Boisduval)的联合毒力作用。结果表明:9种复配剂对朱砂叶螨的共毒系数均在200以上,表明两种单剂复配具有显著的增效作用,其中以甲氰菊酯与阿维菌素按有效成分97∶3的比例复配,其增效作用最为显著,共毒系数高达357.7,为最佳配比。     

杀虫单与有机磷杀虫剂混配对粘虫的增效作用研究

采用浸叶法测定了杀虫单分别与几种有机磷杀虫剂混配对粘虫3龄幼虫的联合毒力。结果表明杀虫单与敌百虫以1：3比例混配对粘虫表现为显著增效，共毒系数（CTC）为268．11；杀虫单与三唑磷以1：1、4：3和1：2的比例混配对粘虫表现为增效作用。共毒系数（CTC）分别为132．98、140．21和132．74：杀虫单与毒死蜱以4：1的比例混配表现为增效作用，共毒系数（CTC）为192.91。