Effects of adjuvants on the performance of a novel powdery mildew fungicide, 1-(4-chlorobenzyl)-4-phenylpiperidine

The effects of adjuvants on the performance of a dispersible concentrate formulation (DCI) of a novel powdery mildew fungicide, 1-(4-chlorobenzyl)-4-phenylpiperidine (I) were investigated. The method involved assessment, under glasshouse conditions, of the therapeutic (curative) control of infections of powdery mildew (Erysiphe graminis DC f.sp. hordei Marchal) on barley (Hordeum vulgare, L.) eight to nine days after spray application to plants that had been inoculated one day prior to spraying. The results from the first trial showed that marked improvements (∽five-fold) in the performance of DCI could be obtained by the spray tank addition of some types of surfactant adjuvants and a series of further trials investigating a wide range of adjuvants was conducted. Nonylphenol, alkylamine and alcohol ethoxylates varying in mean ethylene oxide content between 5 and 20 moles were highly effective. There were indications that optimum performance enhancements were obtained with these surfactants containing between 5 and 10 moles ethylene oxide. Lower enhancements, sometimes only marginal, were obtained from trisiloxane, phosphate ester, propylene oxide, alkylamine-propylene oxide and castor oil ethoxylates and also alkyl polyglucoside biosurfactants. Negligible adjuvant enhancements were observed with emulsifiable paraffinic/naphthenic and rape seed oils, though slightly better enhancements were seen with an emulsifiable transmethylated rape seed oil and, interestingly, larger enhancements with an emulsifiable lipophilic alcohol. A final trial identified the alcohol ethoxylate, ‘Dobanol’ 91-6, as the most effective adjuvant and that its optimum application rate under glasshouse conditions was 250 g ha^-1. This information will be used to guide the design of field trials. © 1997 SCI     

Effect of adjuvants on the performance of the new cereal fungicide,metconazole. I glasshouse trials

Metconazole, (1RS, 5RS; 1RS, 5SR)-5-(4-chlorobenzyl)-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol, is a highly active fungicide, in particular controlling seed-borne and foliar diseases of cereals, such as wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). In order to maximize its foliar activity, an experimental survey of some types of surfactants and an emulsifiable oil was undertaken. Two types of metconazole formulation were investigated using a biological assay involving the therapeutic control of two diseases (Erysiphe graminis DC f. sp. tritici Marchal and Leptosphaeria nodorum Muell.) of wheat. Enhancements of activity by ?Genapol’? C12/C14 alcohol ethoxylates of an emulsifiable concentrate (ECM) formulation of metconazole were approximately three- to four-fold. For its, initially, less active suspension concentrate (SCM) formulation, enhancements were around 35-fold, so that with these adjuvants the two formulations were of similar activity. The enhancement ability of these ?Genapol’? surfactants was optimal at lower (5–10 moles) ethylene oxide content. These analogues induced marginally better enhancements of activity than members of a range of nonylphenol ethoxylates (?Arkopal’?), and emulsifiable paraffinic/naphthenic oil (HVI 60E) and a castor oil ethoxylate (?Atlas’? G1281) but were equivalent to a similar series of alcohol ethoxylates (?Dobanol’?) from another source. Varying the alkyl chain length between C₉-C₁₁ and C₁₄-C₁₅ in the ?Dobanol’? series had little effect on their high enhancements of metconazole activity. It was determined from trials varying the application rate of the best alcohol ethoxylates that application rates of 1–1.5 kg ha^?1 were required for maximum activity. This implied the use of high adjuvant/metconazole ratios in one-pack adjuvant-containing formulations. A range of soluble liquid (SL) formulations were prepared with either ?Dobanol’? 23–6.5 or ?Dobanol’? 91-6/metconazole ratios varying from 5:1 to 15:1. There were found to be highly active and were recommended for field testing.     

Effect of Adjuvants on the Therapeutic Activity of Dimethomorph in Controlling Vine Downy Mildew. I. Survey of Adjuvant Types

The effect of adjuvants on the performance of emulsifiable concentrate (EC) and wettable powder (WP) formulations of dimethomorph, a new systemic Oomycete fungicide, has been investigated using a two-day therapeutic (curative) assay with downy mildew (Plasmopara viticola, Berl. & de T.) on vines (Vitisvinifera L., cv. Cabernet Sauvignon) in glasshouse trials. The EC formulation had some therapeutic activity in this type of test. This activity was increased by the spray tank incorporation of 6 g litre⁻¹ of either emulsifiable rape seed oil (‘Atplus’ 412) or emulsifiable paraffinic oil (‘Atplus’ 411F). However, these improvements in performance were overshadowed by those brought about by incorporation of 3 g litre⁻¹ of a series of C₁₃/C₁₄ alcohol ethoxylates varying in ethylene oxide content from 5 to 20 moles:(‘Marlipal’ 34/6EO, 34/11EO, 34/20EO). Nearly complete fungal control was obtained in the presence of these adjuvants with a dimethomorph application rate of 25 g ha⁻¹ compared with only around 90% control at 400 g ha⁻¹ without adjuvants. The WP formulation was inactive in this therapeutic test but the presence of the adjuvants improved the performance of this formulation towards the high levels observed with the EC plus adjuvants, demonstrating that adjuvants could markedly influence the performance of solid, otherwise therapeutically inactive, dimethomorph formulations. Further trials examined other types of adjuvants (nonylphenol, alkylamine and silicone ethoxylates) but either they were no better than the alcohol ethoxylates or they induced unacceptable phytotoxicity. Trials with alcohol ethoxylates (‘Genapols’) from another source demonstrated activity equivalent to the ‘Marlipal’ surfactants. A two-factorial matrix experiment with ‘Genapol’ C050 showed that, under glasshouse conditions, >90% control could be obtained with the dimethomorph EC at 25 g AI ha⁻¹ with 375 g ha⁻¹ ‘Genapol’ C050. Applications of the WP formulation required slightly higher rates of either 50 g AI ha⁻¹ plus 375 g ha⁻¹ ‘Genapol’ C050 or 25 g AI ha⁻¹ plus 750–1500 g ha⁻¹ ‘Genapol’ C050. The overall conclusion was that alcohol ethoxylates varying in alkyl chain length from C₁₂ to C₁₈ and ethylene oxide content between 5 and 20 moles for the C₁₂ surfactants and ∽15 moles for the C₁₈ surfactants were effective adjuvants in promoting the therapeutic activity of dimethomorph formulationsagainst P. viticola on glasshouse-propagated vines.     

Reinvestigating adjuvants for the wild oat herbicide,flamprop-M-isopropyl. II: Field performance

A field trials programme was conducted in which the performance of a new emulsifiable concentrate formulation (ECI) of flamprop-M-isopropyl containing the adjuvant, ‘Dobanol’ 25-7, in a ratio of 2:1 (by weight) with the AI, was compared with the current commercial formulation of ‘Commando’, in combination with its recommended adjuvant, ‘Swirl’, for the control of wild oat (Avena fatua L.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). A further treatment, in which the ‘Dobanol’ 25-7: AI ratio was increased to 4:1 by the spray tank addition of the former, was also included. The mean results from six trials (five wheat, one barley) showed that the addition of ‘Swirl’ to ‘Commando’ was beneficial, increasing wild oat floret control from a mean value of 80% to 92% at current recommended rates (flamprop-M-isopropyl, 600 g ha^?1; ‘Swirl’, 2.5 litre ha^?1). However, combinations of flamprop-M-isopropyl and ‘Dobanol’ 25-7 gave superior levels of control even at lower AI application rates. For example, a mean level of 96% control of Avena spp. was obtained at 300 g AI ha^?1 with 1200 g ha^?1 ‘Dobanol’ 25–7; with even better control at higher rates of application of both components. This improvement in performance was accompanied by a higher risk of crop phytotoxicity than observed with the ‘Commando’/‘Swirl’ mixtures. Symptoms initially were scorch and subsequently growth depression, particularly of tillers. None of the mean values in the six ‘efficacy’ trials reached commercially unacceptable levels, but in a further six ‘crop effects’ trials (three wheat, three barley), in which double rates were applied, the levels of phytotoxicity did become unacceptable and subsequently reduced grain yields. In contrast, two barley ‘crop effects’ trials gave yields higher than the control plots, possibly through the effects of reducing stem length and lodging thereby enabling more efficient harvesting. Nevertheless, there were rates of application of flamprop-M-isopropyl in the range 300–400 g ha^?1 with ratios of ‘Dobanol’ 25-7 in the range 2:1 to 4:1 that would achieve high levels of control of Avena spp. without undue risk of crop phytotoxicity and further trials are planned to support this new adjuvant system.     

Effect of Adjuvants on the Therapeutic Activity of Dimethomorph in Controlling Vine Downy Mildew. II. Adjuvant Mixtures,Outdoor-Hardened Vines and One-Pack Formulations

Previous investigations have shown that certain C₁₂–C₁₈ alcohol ethoxylates with between 5 and 20 moles ethylene oxide gave large enhancements to the therapeutic activity of emulsifiable concentrate (EC) and wettable power (WP) formulations of dimethomorph in controlling two-day-old infections of downy mildew (Plasmopara viticola, Berl. & deT) on glasshouse propagated vines (Vitis vinifera, L.). In a continuation of that work it has been shown that similar enhancements could also be obtained on vines that had been grown under outdoor conditions for two to three weeks before treatment (outdoor-hardened vines) and it is concluded that the treatments would therefore be effective on field vines. Mixtures of either ammonium sulfate or the silicone ethoxylate, ‘Silwet’ L77, with the best alcohol ethoxylates, ‘Genapol’ C050 or ‘Genapol’ C080, produced slight antagonism of the action of the ‘Genapols’ and therefore were of no benefit. Trials with one-pack formulations prepared containing the ‘Genapol’ adjuvants produced good dose response curves from which estimated doses for 90% fungal control (ED₉₀ values) could be calculated by Logit analysis. These one-pack formulations were significantly more effective than the standard EC formulation (ED₉₀=335 g AI ha⁻¹, glasshouse vines and 445 g AI ha⁻¹, outdoor hardened vines) with optimum enhancements with those formulations containing an adjuvant: dimethomorph ratio of either 9:1 on glasshouse vines (ED₉₀= 13 g AI ha⁻¹) or 6:1 on outdoor-hardened vines (ED₉₀=30 g AI ha⁻¹). This last result was significantly better than that obtained with a commercial formulation of cymoxanil, ‘Fytospore’, (ED₉₀=86 g AI ha⁻¹) and encouraged the recommendation that these one-pack formulations should be examined in field trials.     

Adjuvant Effects on the Therapeutic Control of Potato Late Blight by Dimethomorph Wettable Powder Formulations

Dimethomorph is an effective Oomycete fungicide useful for the control of late blight (Phytophthora infestans, deB) on potatoes (Solanum tuberosum, L.) by preventative (prophylactic) sprays. The results of glasshouse trials using S. tuberosum plants inoculated one day prior to treatment showed that the weak to moderate curative (therapeutic) action of a wettable powder formulation of dimethomorph (WP1) could be substantially enhanced by spray tank adjuvants. A limited survey of surfactant adjuvants indicated that enhancements of performance of WP1 varied with the ethylene oxide content in two series of surfactants, C₁₂/C₁₄ alcohol ethoxylates (‘Genapol’ C series) and nonylphenol ethoxylates (‘Arkopal’ N series). Optimum enhancements were obtained with intermediate degrees of ethoxylation and ‘Genapol’ C080 was adjudged to be marginally superior to its analogues and superior to all of the ‘Arkopal’ series, as well as to a silicone ethoxylate/propoxylate (‘Silwet’ L-77), an alkylamine ethoxylate/propoxylate (‘Armoblen’ 557), and sodium sulfosuccinate (‘Aerosol’ OTB). It was also superior to an emulsifiable paraffinic/naphthenic oil (HVI 60E). Further trials established that relatively high application rates (1000–1500 g ha⁻¹) of ‘Genapol’ C080 were required for maximum enhancement and that the presence of mancozeb, as a co-fungicide, did not substantially affect the enhancement of the therapeutic performance of dimethomorph by ‘Genapol’ C080.     

Effect of the Volume Rate of Application on the Glasshouse Performance of Crop Protection Agent/Adjuvant Combinations

The effects of volume rate of application on the glasshouse performance of three recently developed crop protection agent/adjuvant combinations are discussed. High volume rates of application on easy-to-wet foliage, such as potato (Solanum tuberosum, L.) caused reduction of the adjuvant-enhanced performance of dimethomorph seen at low volume rates. These reductions were largely attributable to relatively lower spray retention with spray drop coalescence and run-off being observed, particularly at the higher adjuvant rates. On difficult-to-wet foliage (wheat, Triticum aestivum, L.; oat, Avena sativa, L.) two different effects were seen. With a metconazole formulation/‘Dobanol’ 91-6 combination on wheat, no systematic changes in performance were observed with change in volume rate. With a flamprop-M-isopropyl formulation/‘Dobanol’ 25-7 combination, statistically significant increases in performance were seen with increasing volume rate. In both cases the observations can be explained as the result of a combination of interacting factors involving spray pattern, spray deposition and, by inference, foliar uptake of the crop protection agent, the proportions of which differed between the two cases. It is suggested that the effect of volume rate of application on performance of adjuvant-containing formulations is investigated on easy-to-wet foliage to determine the upper limits and on difficult-to-wet foliage to determine any variation in performance that may occur. Such information will guide the design of field trials and may aid interpretation of field results.     

The effects of six adjuvants on the rainfastness of chlorpyrifos formulated as an emulsifiable concentrate

The chemically different adjuvants ‘Agral’, ‘Bond’, ‘Codacide Oil’, Li 700, ‘Silwet L’-77, and ‘Headland Guard’ were assayed to determine their effects on the rainfastness of an emulsifiable concentrate formulation of the organophosphorus pesticide chlorpyrifos. Cabbage leaves were each treated with 200×0.25-μl droplets of diluted formulation using a hand-held microapplicator. Droplet deposits were left to air-dry for 1 h prior to exposure to simulated rainfall. Rain fastness was assessed using GC residue analyses of treated leaves after exposure to 10, 20 or 30 min simulated rainfall. The results indicated that the latex-based adjuvants ‘Bond’ and ‘Headland Guard’ induced a statistically significant increase in rainfastness, results for the other adjuvants assayed being either not significant or inconclusive. The results are discussed within the context of using adjuvants to enhance insecticide efficacy. ©1999 Society of Chemical Industry     

Effect of adjuvants on the performance of the new cereal fungicide,metconazole. II Field trials

Glasshouse trials had shown that the activity of metconazole formulations against cereal foliar diseases could be enhanced by alcohol ethoxylate adjuvants. A series of soluble liquid (SL) formulations of metconazole had been prepared containing adjuvant: metconazole ratios of 5:1, 7.5:1, 10:1, 15:1 m/m (SL1, SL2, SL3, SL4) which glasshouse trials had shown could give equivalent performance to an emulsifiable concentrate formulation, (ECM) of metconazole at application rates up to three- or four-fold lower than that of ECM alone. A field trials programme was undertaken to compare the performances of these SL formulations with ECM at 120 g AI ha^?1, through a range of application rates (48, 60, 72, 84 g AI ha^?1), in a non-orthogonal factorial trial design against diseases that occurred naturally (Septoria tritici Rob., Puccinia recondita Rob., Pyrenophora teres Drechs., Erysiphe graminis DC) or by artificial inoculation (Leptosphaeria nodorum Muell.), on either Triticum aestivum L. or Hordeum vulgare L. The results from trials in three locations showed that the commercially acceptable performance of ECM at 120 g AI ha^?1, in giving high levels of control of P. recondita, S. tritici and L. nodorum (both prophylactic and therapeutic activity) on T. aestivum. and of E. graminis and P. teres on H. vulgare, could be matched or improved by SL2, SL3 and SL4 at 72 g AI ha^?1. Furthermore, control of E. graminis f. sp. tritici Marchal by these SL formulations at this application rate was better than that by ECM at 120 g AI ha^?1, though the levels of control still remained below commercial acceptability for therapeutic activity. Nevertheless, substantial reductions in the application rate of metconazole have been achieved by using one-pack adjuvant-containing formulations in field trials, while still maintaining excellent control of a range of cereal foliar diseases. The choice between these SL formulations could therefore be made on other grounds such as cost/performance and ease of formulation.     

四种喷雾助剂对嘧菌酯在玉米叶片上耐雨水冲刷能力及其对玉米安全性的影响

在室内模拟雨水冲刷条件下,分别通过荧光显微镜法和高效液相色谱法探究了添加4种自制喷雾助剂AY904-1 (含有40%乙酸乙烯酯-丙烯酸共聚物和10%异构醇聚氧乙烯醚)、AY904-2 (含有30%乙酸乙烯酯-丙烯酸甲酯共聚物和10%异构醇聚氧乙烯醚)、AY904-3 (含有20%乙酸乙烯酯-丙烯酸乙酯共聚物和10%异构醇聚氧乙烯醚) 和AY904-4 (含有10%乙酸乙烯酯-丙烯酸丁酯共聚物和10%异构醇聚氧乙烯醚) 对提高嘧菌酯在玉米叶片表面耐雨水冲刷效果的影响,并测定了喷雾助剂对嘧菌酯药液物理性状及其玉米安全性的影响。结果表明:在室内模拟冲刷试验中,两种检测方法所测结果具有良好的相关性;在嘧菌酯中添加质量分数为0.1%~1.0%的AY904-1和AY904-2以及添加质量分数为0.5%~1.0%的AY904-3和AY904-4均可显著提高嘧菌酯在玉米叶片上的持留量,且助剂的添加量越大,耐冲刷效果越好,其中以AY904-1的效果最好。在嘧菌酯药液中添加4种喷雾助剂,均能降低药液在玉米叶片表面的接触角,但与嘧菌酯药剂对照相比无显著差异。AY904-1和AY904-2的干燥薄膜在水中溶胀度较低,成膜性能较好。将4种喷雾助剂与氯虫苯甲酰胺药液桶混后喷雾,发现其对3个品种玉米均有很高的安全性。     

Investigation of an emulsifiable oil adjuvant and its components on the activity of a new grass herbicide by factorial experimentation

The herbicidal activity of a new compound [(±)-(EZ}-2-[1-allyloxy-imino)propyr]-3-hydroxy-6-(4-cyanophenyl)cyclohex-2-ene-1-one] (I) , selective to broad-leaf plants, and partially selective in some cereal crops was enhanced by an emulsifiable paraffinic oil (HVI 60E). In order to determine the amount of HVI 60E to be applied with an emulsifiable concentrate of I (IE) a factorial herbicidal assay involving six concentrations of I and five concentrations of HVI 60E (both sets including zero concentration) was conducted to obtain response surfaces of herbicidal activity. The total selectivity of IE in broad-leaf species remained for all HVI 60E concentrations. The activity against grass weeds, except Poa annua L., increased markedly with increasing HVI 60E concentration and enhancement of performance of IE by HVI 60E in broad-leaf crops could be pursued without fear of crop phytotoxicity. However, the increases in activity against grass weeds were accompanied by increases in phytotoxicity against cereal crops. The response surfaces of Echinochloa crus-galli(L.) Beauv. and Zea mays L. were coincident and this result terminated further testing in this outlet. However, the response surfaces of Avena fatua L. and Triticum aestivum L. were reasonably well separated. Further tests in this outlet and in broad-leaf crops are planned around optimum cost-performance ratios derived from combinations with cost-response surfaces. The results of a further lest showed that both components (oil and emulsifier) of HVI 60E were approximately equivalent in adjuvant enhancement activity and so, on cost grounds, a crop oil (low emulsifier content) would be preferred over a crop oil concentrate (high emulsifier content).     

Efficacy of new EC formulations of neem oil and pungam oil for the management of sheath rot disease of rice

Neem oil (NO) and pungam oil (PO) based emulsifiable concentrate (EC) formulations,viz., neem oil 60 EC (acetic acid) [NO 60 EC(A)], neem oil 60 EC (citric acid) [NO 60 EC(C] and neem oil + pungam oil 60 EC (citric acid) [NO+PO 60 EC(C)], which had been developed at Tamil Nadu Agricultural University, were evaluated for their efficacy against sheath rot of rice. All three formulations effectively inhibited the mycelial growth of the pathogen,Sarocladium oryzae, underin vitro conditions. There was no significant difference between efficacy of the freshly prepared and stored formulations in arresting the growth ofS. oryzae; efficacy was maintained even after 9 months of storage. These formulations effectively controlled rice sheath rot and led to increased yield in five field trials. Among the various treatments, the formulation NO 60 EC(A) achieved the highest grain yield in four out of five field trials, with a pooled mean grain yield of 4684 kg/havs 3882 kg/ha in the control. NO 60 EC(A) achieved the maximum cost-benefit ratio of 1:4.8, followed by NO+PO 60 EC(C), with 1:3.3.     

A scanning electron microscope study of glyphosate deposits in relation to foliar uptake

The effects of several formulations on foliar uptake of glyphosate, and on the morphology of glyphosate deposits on leaves, were examined in Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.). [¹⁴C]glyphosate, in the form of the free acid or the isopropylamine salt (IPAS), was applied to foliage alone or with various adjuvants. Uptake of all glyphosate IPAS formulations was greater than that of the corresponding acid formulation. Addition of ‘Tween 20’ enhanced the uptake of glyphosate IPAS compared to glyphosate alone, but had no effect on the uptake of glyphosate acid. Ammonium sulfate and the ‘Roundup’ formulation blank increased the uptake of glyphosate acid and IPAS to 2-3 times that of herbicide alone. Surface deposits, as observed by scanning electron microscopy, varied with the formulation of the herbicide, although there were no differences between the acid and IPAS formulations. Glyphosate alone initially formed a deposit with both crystalline and smooth, amorphous areas. Later in the treatment period (48 and 72 h after application), the deposit was almost entirely crystalline. The addition of ‘Tween 20’ or of formulation blank resulted in the formation of a more amorphous, non-crystalline deposit. Herbicide solutions containing ammonium sulfate dried to form a highly crystalline deposit. However, crystals similar to those of glyphosate alone were not visible in these deposits. The ability of these adjuvants to prevent or delay crystal formation may play a role in their enhancement of herbicide uptake.     

Management of grain discoloration of rice with solvent-free EC formulations of neem and pungam oils

Neem and pungam oil-based emulsifiable concentrate (EC) formulations developed at Tamil Nadu Agricultural University were evaluated for their efficacy to inhibit the mycelial growth of the fungiHelminthosporium oryzae and Pyricularia oryzae causing grain discoloration on rice underin vitro conditions. All three formulations,viz., neem oil 60 EC (acetic acid), neem oil 60 EC (citric acid) and neem oil + pungam oil 60 EC (citric acid), inhibited mycelial growth of the pathogens; they were effective even after 9 months of storage. These formulations effectively controlled the grain discoloration on rice.     

液体农药制剂中烷基酚及其聚氧乙烯醚类助剂的高效液相色谱分析

建立了一种测定6类液体农药制剂中烷基酚（alkylphenols,APs）及其聚氧乙烯醚类（alkylphenol ethoxylates,APEOs）助剂的高效液相色谱-荧光分析方法。乳油、水剂、水乳剂、悬浮剂、可溶液剂和微乳剂样品均经甲醇超声辅助提取,稀释后过聚丙烯膜,采用Poroshell 120 EC-C18（4.6 mm×100 mm,2.7 μm）分离,V（甲醇）:V（乙腈）:V（水）=75.5:6.5:18.0三元流动相等度洗脱,荧光检测器检测,外标法定量。结果表明:在0.05~10或0.1~20 mg/L范围内,APs和APEOs的峰面积与其质量浓度间呈良好线性关系（R2均大于0.999 8）;在添加水平范围内（APs:0.5、2、5 mg/g;APEOs:1、5、25、50 mg/g）,6类液体农药剂型中APs和APEOs的平均回收率为73%~110%,相对标准偏差为0.6%~14.9%,方法的定量限在0.5~1 mg/g。该方法简单、快速、准确,适用于不同液体农药制剂中烷基酚及其聚氧乙烯醚类助剂的测定。     

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.     

顶空气相色谱法检测农药乳油制剂中甲醇含量

建立了农药乳油制剂中甲醇含量快速检测的顶空气相色谱分析方法。以环己烷为内标,采用DB-1701毛细管色谱柱进行分离,氢火焰粒子化检测器(FID)测定。结果表明,该方法在甲醇体积分数为0.1%～1%范围内线性关系良好,回归方程的相关系数为0.999 1,7次平行测定的相对标准偏差(RSD)小于1.33%,空白溶液甲醇的添加回收率在95%～100%之间。该方法简单实用,可以为其他农药液体制剂中易挥发有毒助剂的检测提供参考。     

浅谈农药乳油制剂面临的挑战

随着人类环境保护意识的增强,农药乳油制剂中使用大量的有机溶剂带来的安全和环保问题逐渐为人们所认识,农药乳油制剂面临着生死挑战。发展高质量浓度的乳油产品及开发天然植物源溶剂取代传统芳烃类有机溶剂。是农药乳油制剂的必然发展出路。     

五种喷雾助剂对240 g/L螺螨酯悬浮剂和15%哒螨灵乳油防治木瓜秀粉蚧的增效作用

为探索喷雾助剂对药液物理性状的影响及防治木瓜秀粉蚧的增效作用,室内条件下研究了添加5种喷雾助剂[芦荟精油、有机硅助剂silwet408、渗透剂JFC-2、氮酮和增效醚(PBO)]对240 g/L螺螨酯悬浮剂和15%哒螨灵乳油表面张力、扩展直径以及最大持留量的影响,并测定了添加喷雾助剂对2种供试药剂防治木瓜秀粉蚧Paracoccus marginatus的增效作用。结果表明:5种助剂均能显著降低药液的表面张力、增大扩展直径并提高药液持留量;室内毒力测定结果表明,5种助剂对240 g/L螺螨酯悬浮剂和15%哒螨灵乳油的毒力具有不同程度的增效作用,增效比分别达5.1%～26.1%和22.7%～41.8%,其中JFC-2和PBO的增效作用较为明显。田间试验结果表明,JFC-2和PBO可提高2种供试药液对木瓜秀粉蚧的田间防效,尤其对高浓度药液的增效作用更为明显,其中JFC-2对240 g/L螺螨酯悬浮剂防效的增效比在10.3%～24.6%之间,增效醚对15%哒螨灵乳油防效的增效比在12.1%～28.9%之间。     

Effect of additives in aqueous formulation on the foliar uptake of dimethomorph by cucumbers

BACKGROUND: The efficacy enhancement of dimethomorph formulation by several adjuvants is thought to be through increased foliar uptake. In order to identify the most effective adjuvants, the adjuvancy of 36 additives was examined in aqueous formulations in relation to the absorption of dimethomorph by cucumber leaves. RESULTS: Polyethylene glycol monohexadecyl ethers with ethylene oxide (EO) contents of between 7 and 20, polyethylene glycol monooctadecyl ethers with EO contents of between 10 and 20 and polyethylene glycol monooctadecenyl ethers with EO contents of between 6 and 20 were effective adjuvants for promoting dimethomorph uptake from both aqueous acetone solutions and aqueous wettable powder (WP) suspensions into cucumber leaves. Polyethylene glycol monododecyl ethers with EO contents of between 7 and 9 were effective in promoting dimethomorph uptake from aqueous WP suspensions but less effective relative to the other adjuvants tested with aqueous acetone solutions. Foliar uptake of dimethomorph was also facilitated by the addition of methyl hexadecanoate, methyl octadecenoate and methyl octadecadienoate. CONCLUSIONS: Although the foliar uptake of dimethomorph from both aqueous WP suspensions and aqueous acetone solutions was greatest in the presence of fatty alcohol ethoxylates generally having a C₁₆ or C₁₈ lipophile, uptake from aqueous surfactant–acetone solutions was, on average, 7.6‐fold greater than that from aqueous WP suspensions containing surfactant. Copyright © 2009 Society of Chemical Industry