Development of a nephelometric version of the CIPAC method for measuring dilute emulsion stability

The characterisation of emulsions at dilution rates greater than 1:20, currently used in most international specifications for agrochemical emulsifiable concentrate (EC) formulations, is becoming increasingly important. CIPAC MT36.2 is the internationally-accepted test method for determining the bulk stability of emulsions containing 10 ml litre^?1 or less of added EC. A new nephelometric version of this test method has been examined which, although not as accurate as the official method, gives more rapid results. An assessment of the new method against the official method at a working concentration of 5 ml litre^?1 is reported. Agreement is good, despite the semi-empirical nature of the new method, but only if emulsions are re-emulsifiable at the end of the standing period. The scope of the method is discussed and areas of application indicated.     

Cipac collaborative study to test a colorimetric method for determination of the stability of dilute emulsions

A colorimetric method for the determination of the stability of dilute emulsions (down to 1 ml litre^?1) of emulsifiable concentrates (EC) has been subjected to a collaborative study with 27 participating laboratories, on behalf of the Collaborative International Pesticides Analytical Council (CIPAC). A dye is added to the emulsifiable concentrate and an aliquot is poured into standard water to obtain an aqueous emulsion. After a specified time, the absorbance of an aliquot of the dyed emulsion is measured and compared to the absorbance measured after initial formation of the emulsion. Collaborators were furnised with four emulsifiable concentrate formulations and the dye, and requested to make three replicate determinations on each dyed sample in CIPAC standard waters A and D. The repeatability and reproducibility figures obtained in these trials indicate that the method permits a good estimation of the stability of dilute emulsions when it is followed exactly.     

代森锰锌液相色谱法成功晋升为CIPAC方法的历程与启示

由利民化学有限责任公司自主研发的代森锰锌液相色谱分析方法,历时4年,终于在2019年德国布伦瑞克召开的第63届国际农药分析协作委员会(CIPAC)年会上顺利通过答辩,成功晋升为CIPAC方法。本文对此过程进行了总结梳理,以为我国农药标准方法走向国际提供借鉴。     

仲丁威三种测定方法的比较

本文采用反相高效液相色谱法和改进的气相色谱法对仲丁威含量进行了测定,并与ＣＩＰＡＣ采用的正相高效液相色谱法测定了进行了比较。结果表明,反相液相色谱法与正相液相色谱法等效,气相色谱法经改进后降低了仲丁威的热分解,三种方法对仲丁威原药及乳油含量的测定结果的相对误差在允许的范围之内。     

Efficacy of crude seed extracts of Annona squamosa against diamondback moth,Plutella xylostella L. in the greenhouse

Experiments were conducted to assess the efficacy of crude seed extracts of Annona squamosa collected from Ambon (Maluku, Indonesia) against larvae of the diamondback moth, Plutella xylostella L., feeding on cabbage. Three greenhouse trials were carried out using aqueous seed extracts and an aqueous emulsion of ethanolic seed extracts. At a concentration of 0.5% (w/v), an aqueous emulsion of an ethanolic seed extract was 2.5 fold more effective than 1% rotenone, a commercial botanical insecticide. Crude aqueous seed extracts showed efficacy comparable to pyrethrum, the most widely used botanical insecticide. Seed extract of A. squamosa is a promising candidate for development as a simple botanical insecticide for local use in rural Indonesia.     

Factors affecting foliar retention of some model adjuvant oil-in-water emulsions

The foliar retention of dilute oil-in-water emulsions containing three chemical types of adjuvant oil formulated either as ECs or EWs was compared in track-sprayer experiments using the water-soluble tracer, fluorescein. Although both types of emulsion enhanced tracer deposition onto water-repellant pea and barley foliage, compared with sprays containing no adjuvant, consistently better retention was achieved using the EW emulsions, irrespective of oil composition. On young plants, fluorescein retention using the EC emulsifier alone was similar to that from the corresponding emulsions. However, on older plants, retention from EC emul-sions was superior to that from the EC emulsifier. Compar-able effects were not observed using the EW stabiliser, which had little influence on the efficiency of spray deposition. The retention behaviour of the various oil-based adjuvants is discussed in relation to their effects on spray quality and their formulation ingredients. © 1998 Society of Chemical Industry     

1％阿维·鱼藤新型乳油防治柑橘红蜘蛛田间药效试验

采用1％阿维·鱼藤新型乳油对柑橘红蜘蛛进行田间药效试验。结果表明,1％阿维·鱼藤新型乳油500、1000和1500倍液3个处理对活动螨态均具优异的杀灭效果,药后1d,500倍液处理组防效显著高于对照药剂200阿维·哒3000倍液处理,二者各为99．70%±0．30％和93．64%±2.29％;药后5d,1％阿维·鱼藤新型乳油500、1000和1500倍液3个处理对活动螨态的防效与对照药剂相当,4者防效均高达94．72％以上。此外,1％阿维·鱼藤新型乳油1500、1000和500倍3个处理均对柑橘红蜘蛛螨卵具一定的杀卵效果,其中500倍处理组的杀卵作用较好,校正杀卵率达80．59%±2．51％。     

Relation between volatility rating and composition of phenoxy herbicide ester formulations

A CIPAC/AOAC test with tomato plants is used to specify the volatility ratings of herbicide ester formulations. This work compares the tomato plant test with an alternative chemical one. The concentrations of esters and the effective molecular weight and density of each formulation were used with the ester vapour pressures to calculate its herbicide vapour pressure as complete, and evaporated formulations. The range was from 28.8 mPa (at 257deg;C) for a mixture of 2,4–D esters to 0–07 mPa (at 25°C) for a 2,4,5–T-(iso-octyl) formulation, as complete formulations, and 35-5 and 0–16 mPa (at 25°C) as evaporated ones. A value of 0–6 mPa (at 25°C) was selected on the basis of the tomato plant test as the cut-off area for low-volatile esters and is recommended to be included in specifications for herbicide esters. Formulations with a herbicide vapour pressure above 3.3 mPa (at 25°C) are high-volatile ones according to the tomato plant test, while between 0–6–3.3 mPa (at 25°C) is a borderline region where the test gives mixed results. Levels of 2,4–D-ethyl and methyl were added to pure 2–ethylhexyl esters of 2,4–D and a 2,4,5–T-(iso-octyl) formulation to find what level of contamination would change the rating of these esters from low to high volatile. Formulations of 2,4–D-(iso-octyl) should not contain more than 11 g litre^?1 2,4–D as methyl ester or 2.0 g litre^?1 2,4–D as ethyl ester. Formulations of 2,4,5–T-(iso-octyl) should not contain more than 26 g litre^?1 2,4–D as methyl ester or 4.7g litre^?1 2,4–D as ethyl ester.     

Interaction of Moniliophthora perniciosa biotypes with Micro‐Tom tomato: a model system to investigate the witches' broom disease of Theobroma cacao

The miniature tomato (Solanum lycopersicum) cultivar Micro‐Tom (MT) has become an important platform to investigate plant–pathogen interactions. In the case of the witches' broom disease of Theobroma cacao (cacao), the existence of Moniliophthora perniciosa isolates pathogenic to Solanaceae (S‐biotype) may enable the use of MT to circumvent limitations of the cacao host, whereas the availability of a non‐infective cacao C‐biotype allows the evaluation of contrasting responses of MT. Infection of MT by the S‐biotype led to stem swelling and axillary shoot growth to form broom‐like symptoms similar to the biotrophic phase in cacao, but the infected tissues did not progress to necrosis. Conversely, inoculation with the C‐biotype did not cause typical symptoms, but reduced plant height, appearing as a non‐host interaction. Histopathological characterization of the S‐biotype infection of MT by light and electron microscopy indicated limited germ tube penetration, preferentially through wounds at the base of trichomes or actively through the epidermis. No intracellular mycelium was observed, corroborating the lack of the necrotrophic stage of the pathogen. The analysis of gene expression during the interaction between the S‐ or C‐biotype with MT indicated that expression of plant defence‐associated genes differs for kinetics and intensity between a compatible or incompatible M. perniciosa–MT interaction. The pattern of spore germination and low rate of mycelia penetration suggests that the S‐biotype is not a fully adapted tomato pathogen, but possibly a case of broken non‐host resistance, and evidence suggests the occurrence of a non‐host MT response against the C‐biotype.     

Interaction Effect of Water Magnetization and Water Salinity on Yield,Water Productivity and Morpho-Physiological of Balkız Bean (Phaseolus vulgaris)

Developing new tools for using low-quality irrigation waters is vital for the sustainability of irrigated agriculture and minimizing salt accumulation. Therefore, the present study focused on the interactive influence of irrigation treatments (magnetized (MT) and non-magnetized (NMT)) and water salinities (0.38, 1.5, 4.5, and 7.0?dSm^?1) on soil salinity, water use efficiency, yield and morpho-physiological changes of Balk?z bean. A pot experiment was conducted in a randomized complete block design with three replications under the rain shelter condition. Irrigation water MT treatment increased fresh bean yield, water use efficiency (WUE) and irrigation water use efficiency (IWUE) by 21.35, 23.00 and 14.8%, respectively, while saturated soil salinity was reduced by 20%, compared to NMT treatments. The leaf area, stomata, and leaf succulence in green beans in the MT treatment significantly increased by 13.4, 23.9, and 3.3% compared with those in the NMT treatment. Stems of the bean crops were more sensitive to salinity stress followed by roots and leaves. The study revealed that irrigation with magnetically treated water manages salinity related yield loss through increased morphological features as well as osmotic and stomatal adjustments. In addition, the bean crops showed an ability to protect water in tissue against salinity toxicity up to 5.24?dSm^?1 soil salinity level under magnetized saline water conditions. Finally, irrigation with magnetically treated 0.38?dSm^?1 irrigation water can be recommended due to providing a higher yield, WUE, IWUE, and sustainable production under saline irrigation in water scarcity regions.

     

Recent development in suspoemulsions

Suspension emulsions or suspoemulsions result from the combination of an emulsion phase, containing one or more active ingredients, with a continuous phase also containing active ingredients but in the form of a solid dispersion. Advantages of such products, which can contain as many as four complementary biologically active ingredients, are elimination of tank mixing; a reduced inventory of products; reduction in the number of applications to a given crop; and savings in time and money. The development of suspoemulsions is discussed and a novel, easy method for their preparation, using latexes, is described. Such products are also useful as feedstock emulsions for other suspension emulsions as well as constituting a stable oil-in-water emulsion delivery system in their own right.     

Detection,quantification and classification of soft rot erwinias associated with potato tubers

An improved method for detection, quantification and classification of soft rot bacteria associated with potato seed tubers, plant material, soil and water has been developed. The method is based on the use of a modified version of the crystal violet pectate selective medium (CVP), enrichment cultures under anaerobic conditions using pectate as the sole carbon source for recovery improvement, and the quantitative estimation ofErwinia spp. by employing a new solid medium - most probable number (MPN) method. The use of this method enabled an improvement in the recovery and identification of specificErwinia spp. in mixed populations. This was done by incubating CVP plates — used for the MPN counting — at three different temperatures (15, 28 and 39°C). These combined techniques were used for estimating low level populations at less than one cell per gram or ml tested ofErwinia carotovora subsp.carotovora, E. carotovora subsp.atroseptica, andE. chrysanthemi.     

Effects of tillage on winter wheat production in Mediterranean dryland fields

The benefits of conservation agriculture (CA) and associated technologies are not equal for all agro ecosystems. This study used a field experiment to examine winter-wheat yield and weeds under conservational and conventional systems in the central region of Spain. The three tillage treatments were conventional tillage (CT), minimum tillage (MT) and no-tillage (NT). The climatic conditions influenced wheat yield, yield components, soil water content and weeds. When the autumn-winter rainfall was abundant and constant (69.7% of annual rainfall), wheat grain yield (4465?kg?ha^?1) and yield components (3897?kg?ha^?1 of straw biomass and 584.5 ear m^?2) were highest. Wheat grain yield was highest with NT: 3549.9?kg?ha^?1 (compared to MT: 2955.1?kg?ha^?1 and CT: 2950.3?kg?ha^?1) and ear number per m² was significantly lower with MT (332 no ear m^?2, compared to 426 and 411.6?ear?m^?2 in CT and NT-systems respectively). Soil water content, at earing stage, was the highest in NT (27.36% of soil moisture) while MT showed the lowest content (11.83% of soil moisture). The higher weed measurements (means of 2.557 plants m^?2; 1.443 species m^?2 and 2.536 g m^?2) was with higher annual rainfall (488?mm). Throughout the experiment it was the dominant presence, in MT-wheat plots, of Lolium rigidum Gaudin (with means from 4.87 to 7.71 plants m^?2), which reduced the ear number per m². Our study revealed that in the short term, under semi-arid conditions, only the adoption of NT system (rather than MT) showed economic benefits.     

酶联免疫吸附测定(ELISA)检测苏云金杆菌伴孢晶体蛋白质研究

用酶联免疫吸附测定(ELISA)检测Bt伴孢晶体毒素蛋白质,最低可检值7.79ng/0.15ml,灵敏、精确,具高度专化性。测定标准品HI—1—S—1980和Bt乳剂产品中伴孢晶体蛋白质含量,分别为108.06mg/g粉剂和4.57—6.17mg/ml乳剂。用标准品与待测样品(Bt乳剂)的晶体蛋白质含量,就可计算出待测样品的相对毒力效价。ELISA与昆虫生测之间有良好的相关性。     

植物源甘油酯与金龟子绿僵菌对黄曲条跳甲的室内毒力及田间防效评价

黄曲条跳甲Phyllotreta striolata是为害十字花科蔬菜的重要害虫,长期使用大量的化学农药,不仅增强了黄曲条跳甲的耐药性,也会导致蔬菜农药残留增加,危害人们的饮食健康。因此,利用绿色防控手段防治害虫成为近些年的研究热点。本文在室内测定了以植物源甘油酯为主要成分的植物油乳剂、绿僵菌以及二者混配液对黄曲条跳甲成虫的毒力并对油菌混配液的田间防控效果进行了评价。室内毒力测定结果表明,施用植物油乳剂50～800倍液时,黄曲条跳甲成虫第2 d的死亡率为37.93%～100%;施用绿僵菌1.25×10⁷～2×10⁸孢子/m L时,黄曲条跳甲成虫第5 d的死亡率为32.2%～93.22%;施用植物油乳剂和绿僵菌混配液时,黄曲条跳甲成虫第1 d的死亡率在95%以上,显著高于2种单剂,且混配液能够极显著缩短黄曲条跳甲致死中时。田间试验结果表明,以植物油乳剂100倍液和绿僵菌1×10⁸孢子/m L混配处理第6 d时,黄曲条跳甲成虫的相对防效和虫口减退率均达60%以上,第8 d时,黄曲条跳甲成虫的相对防效和虫口减退率分别为89.8...     

Determination of tau-fluvalinate residues in honey

A capillary column gas chromatographic method is described for the determination of tau-fluvalinate in honey samples. The method involves solid phase extraction of the sample with two RP C-8 cartridges in series, purification of the extract, if necessary, on a silica cartridge, and detection of the active ingredient with an electron capture detector. The method is rapid and overcomes the problem of emulsion formation in liquid/liquid partition often found in traditional systems. The detection limit in actual samples is 0.01 mg kg^?1 and mean recoveries for fortified samples prepared with or without clean-up are greater than 85%.     

除草剂助剂对药液物理性状及对磺草酮药效的影响

为了探讨除草剂助剂对药液物理性状的影响与其对除草剂药效影响之间的关系,室内分别采用滴重法、接触角仪测定法、液滴干燥法、紫外分光光度仪测定法测定了4种常用除草剂助剂药笑宝、885、机油乳剂(机油标号N32)和信德宝药液的表面张力、接触角、干燥时间以及在叶面上的滞留量,以温室盆栽法测定了这些助剂对磺草酮防除反枝苋、稗草的药效增强作用。结果表明,药笑宝可显著降低药液的表面张力、减小接触角、缩短液滴干燥时间以及增大药液在叶面上的滞留量,其次是885助剂,而机油乳剂、信德宝效果略差。温室测定结果表明,药笑宝对磺草酮药效的增强作用最大,其次是885。说明助剂所致上述物理性状的变化与对磺草酮药效的增强呈现一定的相关性。     

Simultaneous detection and identification of <Emphasis Type="Italic">Pepino mosaic virus</Emphasis> (PepMV) isolates by multiplex one-step RT-PCR

A RT-PCR was developed for the simultaneous detection and identification of three groups of Pepino mosaic virus (PepMV): European/Peruvian, Chilean 1/US1 and Chilean 2/US2 groups, followed by a restriction analysis that allowed the separation of the European, Peruvian, Chilean 2 and US2 isolates (patent pending). The multiplex RT-PCR reaction was performed by a mix of six primers that amplified a part of the RNA-dependent RNA polymerase gene of PepMV plus an internal control. Amplifications resulted in a 980 bp, 703 bp or 549 bp PCR product for European/Peruvian, Chilean 1/US1 or Chilean 2/US2 groups, respectively. For the identification of the isolates present within the European/Peruvian and Chilean 2/US2 groups, the amplified PCR fragments were directly digested with SacI enzyme. The multiplex RT-PCR method presented higher sensitivity to detect CH1/US1 isolates in field samples than the RFLP-PCR method described by Hanssen et al. (European Journal of Plant Pathology 121:131–146, 2008). The detection limit observed with the multiplex RT-PCR was equal to or 3,125 times higher when compared to single RT-PCR or ELISA-DAS and molecular hybridisation methods, respectively. The use of the multiplex RT-PCR method in routine analysis of field tomato samples allowed the detection of 36.2 and 33.4% more positives when compared to the serological and molecular hybridisation methods, respectively, and the identification of plants infected with one, two or three isolates of PepMV.     

Measurement of evaporation from adjuvant solutions using a volumetric method

Various agricultural spray adjuvants are available which are classified as anti-evaporants. This quality has the potential to aid in reducing drift and chemical evaporation and so improving coverage. Numerous other adjuvants not claiming these benefits may have these characteristics which are not being exploited. In order to assess these qualities, a simple, rapid assay was devised for measuring relative evaporation rates from individual drops. This method was then used to measure the evaporation rates of a variety of adjuvants under controlled temperature and humidity conditions. The droplet producing device uses a microliter syringe to dispense a droplet of known size. After a given period of time, the drop is taken back into the syringe and the volume lost to evaporation calculated. Modifications to the original device include suspending the drop inside a temperature- and humidity-controlled chamber. The original device was used for determining the rate of evaporation from water drops later than 0.3 mm. We have extended the use of the device to measure the rates of evaporation from a range of adjuvant solutions under controlled temperature and humidity conditions. The data reported here suggest that this method (a) is suitable for measuring evaporation from drops of many (but not all) adjuvant formulations, (b) is capable of discerning differences in relative rates of evaporation and (c) may be used for an array of adjuvant, drop size, and meteorological conditions. Major limitations appear to be (1) equilibrium surface tension, solutions having values less than c.35 mN m ?1 are difficult to analyze and (2) a lower limit on drop-size of c.300 μm.