共查询到20条相似文献，搜索用时 31 毫秒
1.
Biological activity of fenitrothion on stored maize at various moisture contents and at different times after application was measured by biological assay using adults of Tribolium castaneum (Herbst). Inactivation of actual residues over time was then determined after making the necessary allowance for chemical breakdown. At a given moisture content, the inactivation process was substantially completed during the first 6 weeks after application and loss of effectiveness from 6 weeks onwards resulted mainly from chemical breakdown. At a given time after application, residues were less active at higher moisture content (m.c). Differences in activity between moisture contents were apparent within a few hours of application and continued to increase for up to 3 days, with relatively little change thereafter during storage of 24 weeks. Thus after 24 weeks, residues on maize of 18% m.c. had an activity about 20% that of similarly-aged residues at 10% m.c. and 4% that of freshly-applied residues at 10% m.c. These results were in general accord with changes in the proportion of the residue which was collected from the kernels by a surface wash with methanol, this readily-extractable residue presumably representing the insecticide that may be picked up by insects. 相似文献
2.
Bioassays were conducted in stored grains to evaluate the combined use of the entomopathogenic fungus Beauveria bassiana, diatomaceous earth (DE) and fenitrothion against adults of Rhyzopertha dominica and Tribolium castaneum. The insecticide agents were applied to wheat as follows: the fungus at 1 × 108 conidia/kg of wheat, DE at 3 g/kg of wheat and fenitrothion at a rate of 0.15 ml/kg of wheat (25% of field dose rate). Surviving insects and progeny production were monitored at thirty-day intervals until four months. For both insect species, significantly less progeny was produced on wheat treated with fenitrothion and DE + B. bassiana formulations in comparison with controls. The effect of insecticides on the grain damage, germination power of wheat and bulk density was also evaluated. After four months, B. bassiana mixed with DE reduced the damaged insect grains by 50% in comparison with both fenitrothion and control treatments. Trials using DE caused a reduction in bulk density while there were no significant differences for germination testing between treatments. 相似文献
3.
食蚊鱼Gambusia affinis脑乙酰胆碱酯对杀螟松的反应及恢复 总被引：1，自引：0，他引：1
在静水系统中用不同浓度的杀螟松处理食蚊鱼 96 h分别于第 2 4、4 8和 96 h测定脑乙酰胆碱酯酶(ACh E)的活性。另一些鱼在接触杀螟松之前分别用胡椒基丁醚 (PBO)和磷酚三苯酯 (TPP)做预处理。结果表明 ,在 0 .4 mg/ L和 1.3mg/ L的亚致死浓度下 ,杀螟松对 ACh E活性的抑制率分别为 4 4 .2 %和 6 5.7%与用杀螟松单独处理的鱼相比 ,TPP预处理的鱼 ACh E活性更低 ,而 PBO处理后的鱼 ACh E活性较高。本项研究还测定了鱼经过 96 h杀螟松处理再移到清水中之后 ACh E的恢复情况。经过 8d的恢复期 ,用杀螟松单独处理和经 TPP处理的鱼 ,其 ACh E仍低于对照。 相似文献
4.
1983—1986年通过室内毒力测定比较,在20种供试农药中筛选出杀螟松对麦蚜具有很高毒力,田间试验和示范表明,小麦不同部位农药沉积量同药效呈正相关,杀螟松对小麦各部位的蚜虫均有良好防效。1985—1986年在京、冀、甘、川、豫等省示范和推广10多万亩,每亩用50％乳油30毫升,无论用高容量、低容量、超低容量或吹雾法喷雾,防效均在90％以上。杀螟松是我国正在发展的大吨位农药品种,具有防效好、药源广、成本低、对人畜安全、无残毒等优点。作者认为是值得推荐的防治麦蚜的农药品种。 相似文献
5.
Graham Barson 《Pest management science》1983,14(2):145-152
The toxicities, to a laboratory susceptible strain and to a resistant strain of Oryzaephilus surinamensis (L.), of water-dispersible powder formulations of pirimiphos-methyl, fenitrothion or chlorpyrifos-methyl under constant conditions of 25°C and 70% r. h. were compared to the toxicities when the insects were exposed to a diurnal cycle of 12.5–20–12.5°C and 70–50–70% r. h. to simulate grain store conditions in the UK during spring and autumn. All the insecticides were more effective at 25°C and 70% r. h. The LD50 values for the susceptible strain were low, being 4.4 and 1.4 mg m?2 at 12.5-20°C and 25°C, respectively, for chlorpyrifos-methyl, 18.3 and 4.1 mg m?2, respectively, for pirimiphos-methyl, and 4.0 and < 1.O mg m?2, respectively, for fenitrothion. The LD50 values obtained from the two sets of environmental conditions for a resistant strain (484) differed by factors of 1.8 for chlorpyrifos-methyl, 4.8 for pirimiphos-methyl, and 7.3 for fenitrothion. Toxicity studies were also made with chlorpyrifos-methyl under various constant conditions of temperature and humidity from 5–30°C (5°C intervals) and 30, 50, 70 and 90% r. h., and also at O°C and 60% r. h. Chlorpyrifos-methyl was very effective and there was little or no cross resistance to chlorpyrifos-methyl in the resistant strain. From 15 to 30°C, mortality was high, and differences in mortality at the LD50 level for the various humidities were slight, but there was a decrease in mortality with decreasing humidity at any one temperature, in particular, at 5°C, 50 and 70% r. h., and 10°C and 50% r. h. Chlorpyrifosmethyl was more toxic to both strains at the highest humidity (90%) throughout the whole temperature range. The LD50 values for each strain decreased at each temperature as the water vapour concentration was increased. At O°C and 60% r. h., all the insects from both strains died but the cause of death was not clear. 相似文献
6.
James M. Desmarchelier 《Pest management science》1978,9(1):33-38
Loss of fenitrothion from post-harvest application to wheat, oats, paddy rice and sorghum followed a second-order rate process, with rate of loss being proportional, at a fixed temperature, to the amount of fenitrothion and the activity of water, which was obtained from the equilibrium partial pressure of water vapour. The effect of temperature on loss was of the form of the Arrhenius equation. A chart relating half-life to temperature and relative humidity is presented in a form suitable for field use, and a mechanism is proposed for loss of fenitrothion. 相似文献
7.
不同控氮比掺混肥对土壤无机氮与脲酶及冬小麦产量的影响 总被引：4，自引：0，他引：4
开展田间小区试验,研究了控释氮肥与尿素掺混施用对土壤无机氮与脲酶及冬小麦产量的影响,旨在寻求控释氮肥与尿素最佳掺混比例,提出缓解氮肥损失、降低面源污染、节约成本、易于推广的施肥方式。结果表明:较常规尿素处理,控释氮肥与尿素掺混对土壤铵态氮含量影响总体差异不显著;在小麦分蘖期,常规尿素处理土壤硝态氮含量和土壤脲酶活性较高,而小麦拔节期至成熟期,则以掺混40%比例以上控释氮肥处理的土壤硝态氮含量和脲酶活性较高;各施氮处理对小麦穗粒数和千粒重影响差异不显著,产量以掺混40%控释氮肥处理最高,较常规尿素处理增产14%,因产值最高,投入成本适中,净收入水平和产投比均为最高,分别为5 875.72元·hm~(-2)和2.24,较常规尿素处理提高了23.24%和9.27%。综上,40%控释氮肥与60%尿素掺混处理在提高土壤无机氮含量,激活小麦生长中、后期脲酶活性,增加冬小麦产量方面效果显著。 相似文献
8.
To estimate the impact of fenitrothion on small mammals, a breeding colony of wild southern red-backed voles (Clethrionomys gapperi) was successfully maintained. The red-backed vole is a nontarget species inhabiting coniferous forests that are subjected to aerial spraying of the pesticide for the control of spruce budworm infestations. The voles were used to examine toxicity and the metabolic pathways involved in the elimination of fenitrothion after intraperitoneal injection of the purified, undiluted organophosphate. The 96-hr LD50 was 1330 mg/kg. Toxicities toward males and females were not significantly different. All observed symptoms of intoxication and 99% of the mortality occurred within 48 hr of dose application. All major metabolites of fenitrothion metabolism in nonruminant mammals were identified and quantified by gas chromatography. At all doses, fenitrothion was rapidly metabolized and excreted. No body accumulation of residues was implied. The toxicity of fenitrothion was not correlated with increasing proportion of the dose converted into fenitrooxon. The low toxicity to red-backed voles is probably due, in part, to rapid metabolic detoxication by the two mechanisms cleaving fenitrothion at the P-O-aryl and PO-alkyl bonds, the latter becoming more prominent at high dose levels. 相似文献
9.
Wheat growth in response to soil water deficit play an important role in yield stability. A field experiment was conducted for winter wheat (Triticum aestivum L.) during the period of 2002-2005 to evaluate the effects of limited irrigation on winter wheat growth. 80%, 70%, 60%, 50% and 40% of field capacity was applied at different stages of crop growth. Photosynthetic characteristics of winter wheat, such as photosynthesis rate, transpiration rate, stomatal conductance, photosynthetically active radiation, and soil water content, root and shoot dry mass accumulation were measured, and the root water uptake and water balance in different layer were calculated. Based on the theory of unsaturated dynamic, a one-dimensional numerical model was developed to simulate the effect of soil water movement on winter wheat growth using Hydrus-1 D. The soil water content of stratified soil in the experimental plot was calculated under deficit irrigation. The results showed that, in different growing periods, evapotranspiration, grain yield, biomass, root water up- take, water use efficiency, and photosynthetic characteristics depended on the controlled ranges of soil water content. Grain yield response to irrigation varied considerably due to differences in soil moisture contents and irrigation scheduling between seasons. Evapotranspiration was largest in the high soil moisture treatment, and so was the biomass, but this treatment did not produce the highest grain yield and root water uptake was relatively low. Maximum depth of root water uptake is from the upper 80 cm in soil profile in jointing stage and dropped rapidly upper 40 cm after heading stage, and the velocity of root water uptake in latter stage was less than that in middle stage. The effect of limited irrigation treatment on photosynthesis was complex owing to microclimate. But root water uptake increased linearly with harvest yield and improvement in the latter gave better root water uptake under limited irrigation conditions. Appropriately controlled soil wate 相似文献
10.
The uptake and metabolism of DDT, fenitrothion and chlorpyrifos were studied in cultures of the ciliate protozoan Tetrahymena pyriformis. When cultures were treated with DDT in concentrations varying from 0.01 to 0.5 μg ml−1, concentrations found in T. pyriformis were 3.8 to 335 μg g−1 dry weight. The accumulation of fenitrothion ranged from 28.7 μg g−1 in cultures treated with 1 μg ml−1 to 2260 μg g−1 in cultures treated with 10 μg ml−1. Under similar experimental conditions chlorpyrifos was accumulated from 24.7 to 15400 μg g−1. The patterns of uptake were dependent on the growth cycle, the ability of the organism to metabolise insecticide and the type of the insecticide used. Maximum accumulation of DDT, fenitrothion and chlorpyrifos occurred in 2, 4 and 6 h respectively. Tetrahymena metabolised DDT to DDD and DDE but failed to metabolise fenitrothion and chlorpyrifos. The effects on growth and morphology of T. pyriformis were studied over a period of 5 days. Higher concentrations (10, 50 and 100 μg ml−1) of DDT inhibited only the growth of the organisms and did not change cell morphology. Fenitrothion was extremely toxic to the organisms and at 5 and 10 μg ml−1 cells became more or less spherical and died after 48 h. However, concentrations of 0.5, 1 and 2.5 μg ml−1 fenitrothion caused growth inhibition, but only at 2.5 μg ml−1 was this permanent. Chlorpyrifos inhibited the growth of the organisms at 1, 5 and 10 μg ml−1 but the morphology was affected only at 5 and 10 μg ml−1. 相似文献
11.
Influence of soil moisture on activity and persistence of the strigol analogue GR 24 总被引：1，自引：0，他引：1
Germination of Striga hermonthica (Del.) Bentth seeds in response to the strigol analogue GR 24 was strongly influenced by soil moisture prior to, at, or after, stimulation. Exposure of seeds to excessive soil moisture contents (70% w/w) during conditioning resulted in a low response to GR 24. Transfer of Seeds from soil at 70% moisture to a lower moisture level (47%) for 2 days or more improved the response to GR 24 (37–58% germination), white air-drying restored germination (88%). In Gezira soil the optimum soil moisture contents for maximum response to GR 24 were 44, 38 and 40% during conditioning, stimulation and germination, respectively. The corresponding figures for the sandy soil were 20, 22 and 22%, respectively. Persistence of GR 24 was similar in both soil types, but was strongly influenced by soil moisture content. The stimulant was stable in air-dry soil, but a rapid loss was encountered in moist soil. 相似文献
12.
Anticholinesterase activity in vitro of pure fenitrothion, S-methyl fenitrothion (SMF) and mixtures of both was studied using different sources of cholinesterase. SMF was two to three orders as active an inhibitor as fenitrothion. In the mixtures, 1 and 5% SMF significantly influenced the I50 value of fenitrothion. The hydrolysis rates of both compounds are given. A method for the synthesis of pure SMF is also described. 相似文献
13.
Kavallieratos NG Athanassiou CG Pashalidou FG Andris NS Tomanović Z 《Pest management science》2005,61(7):660-666
Laboratory bioassays were carried out in order to evaluate the effectiveness of two diatomaceous earth (DE) formulations, Insecto and SilicoSec, against adults of Rhyzopertha dominica (F) in eight different grain commodities. The adherence of the two DEs to each grain was also measured. The eight grains tested were wheat, whole barley, peeled barley, oats, rye, triticale, rice and maize. These commodities were treated with the DEs at three rates, 0.75, 1.0 and 1.5 g DE kg(-1) grain. The mortality of R dominica adults was measured after 24 h, 48 h, 7 days and 14 days of exposure in the treated grains at 26 degrees C and 55% RH. After the 14-day mortality count, all adults were removed and the treated grains retained under the same conditions for a further 60 days. The treated grains were subsequently examined for F1 progeny. Significant differences were recorded among the eight grain types as well as between the DE formulations tested. After 14 days of exposure, even at the lowest DE rate for both formulations, adult mortality was high (>90%) in wheat and triticale. In contrast, adult mortality was significantly lower in peeled barley. Increasing the rate improved the efficacy of the DEs significantly in only some of the grains tested. Reproductive capacity in all the treated grains was significantly suppressed when compared with untreated grains. Generally, more F1 individuals of R dominica were noted in the treated peeled barley than in the other commodities. Significant differences in the percentage of DE retention were noted among the eight grains. The highest retention level was noted in rice (>87%) and the lowest in maize (<6%). However, the degree of DE adherence to a given grain was not always indicative of the effectiveness of DE against R dominica. 相似文献
14.
James Desmarchelier Mervyn Bengston Meville Connell William Minett Barry Moore Mervyn Phillips John Snelson Rex Sticka Kenneth Tucker 《Pest management science》1977,8(5):473-483
The accuracy and reproducibility of analytical methods for the assay of five organophosphorus grain protectants have been investigated by a coordinated test programme. Results were assessed using data from field applications of chlorpyrifos-methyl, fenitrothion, malathion, methacrifos and pirimofos-methyl at commercial silos in New South Wales and Queensland. A satisfactory analytical procedure is recommended following an extended series of tests. 相似文献
15.
L. Rosival M. Vargová J. Szokolayová K. Čerey A. Hladká V. Bátora J. Kovačičová Š. Truchlik 《Pesticide biochemistry and physiology》1976,6(3):280-286
The toxicity of the S-methyl isomer of fenitrothion was found to be higher than that of both fenitrothion and technical fenitrothion. Repeated administration of the compound showed a rapid decrease in toxicity with decreasing doses.Excretion of p-nitro-m-cresol into the urine of rats was more rapid and the excreted amounts were larger from a single dose of the isomer than from fenitrothion.Single doses of the isomer increased the pentobarbitone sleeping time in mice at both 24 and 48 hr, but showed no change after 4 days. Administration of the isomer and purified fenitrothion to mice for 1 week had no effect on the pentobarbitone sleeping time, nor did a single dose of fenitrothion change the effectiveness of pentobarbitone.Dominant lethal tests in rats revealed a possible mutagenic effect from this compound.The anticholinesterase activity of the fenitrothion S-methyl isomer in vitro was found to be two to three times higher than that of fenitrothion. 相似文献
16.
James Desmarchelier Mervyn Bengston Richard Davies Brian Elder Richard Hart Ronald Henning William Murray Edward Ridley Eric Ripp Charles Sierakowski Rex Sticka Jack Snelson Barry Wallbank Arnold Wilson 《Pest management science》1987,20(4):271-288
Methacrifos (22.5 g t?1) and the three protectant combinations chlorpyrifos-methyl (10 g t?1) plus bioresmethrin (1 g t?1), fenitrothion (12 g t?1) plus (1R)-phenothrin (2 g t?1) and pirimiphos-methyl (4 g t?1) plus carbaryl (8 g t?1) were each applied to grain that was stored in at least 15 silos. Grain temperature and levels of protectant were regularly monitored, and samples from 12 storages using each treatment were taken for laboratory assays against Rhyzopertha dominica and Tribolium castaneum. Grain condition did not deteriorate during storage. Grain remained free of insects in 60 of the 63 storages treated; partial failure in the other 3 storages was attributed to low or irregular levels of protectant. The mean and range of residue values of all protectants were recorded as a function of time and the mean observed values corresponded to predicted values. In laboratory bioassay, the order of effectiveness against T. castaneum was methacrifos > chlorpyrifos-methyl plus bioresmethrin > fenitrothion plus (1R)-phenothrin = pirimiphos-methyl plus carbaryl. The order of effectiveness against R. dominica was carbaryl plus pirimiphos-methyl = (1R)-phenothrin plus fenitrothion > methacrifos > bioresmethrin plus chlorpyrifos-methyl. 相似文献
17.
Allan Walker 《Pest management science》1976,7(1):50-58
The rates of degradation of simazine and linuron were measured in soil from plots not treated previously with these herbicides. Degradation of both compounds followed first-order kinetics and soil temperature and soil moisture content had a marked effect on the rate of loss. With linuron, half-lives increased from 36 to 106 days with a reduction in temperature from 30° to 5°C at 4% soil moisture, and from 29 to 83 days at 12% soil moisture. Similar temperature changes increased the half-life of simazine from 29 to 209 days and from 16 to 125 days at soil moisture contents of 4 and 12% respectively. A computer program which has been developed for simulation of herbicide persistence was used in conjunction with the laboratory data and the relevant meteorological records for the years 1964 to 1968 in order to test the model against previously published field persistence data for the two herbicides. The results with simazine showed a close correspondence between observed and predicted residue levels but those for linuron, particularly in uncropped plots, were satisfactory for limited periods only. 相似文献
18.
Paul Gaillardon 《Pest management science》1996,47(4):347-354
Long-term sorption of diuron and isoproturon by a clay loam soil was investigated for nine weeks at two herbicide doses (0·6 or 3 mg kg−1) and two soil moisture contents (35 or 62% w/w, i.e. 3·16 or 1 kPa) by measuring changes in herbicide concentrations in the soil solution sampled by means of glass microfibre filters in presence of sodium azide (200 mg litre−1) which inhibited biodegradation for more than four weeks. After the first day equilibration period, where adsorption mainly occurred (>70% adsorbed), herbicide concentrations in the soil solution decreased (about 50% for diuron; up to 38% for isoproturon) for two weeks but equilibration required about one month. Small amounts of herbicides were sorbed during this process (<10% of the initial (24-h) adsorption). These were similar for both herbicides, although diuron was initially more adsorbed. Values of the partition coefficients of herbicides between soil and soil solution were increased (75–125% for diuron; 29–67% for isoproturon). High soil moisture enhanced sorption speed for both herbicides and increased final sorption only for diuron. Sodium azide inhibited long-term sorption of the more stable diuron and this effect was reversed by low temperature only at the low soil moisture. Sodium azide action might be complex (competition, effect on soil micro-organisms) and was not elucidated. 相似文献
19.
Residues of deltamethrin on wheat grain of 12% moisture content, stored in the laboratory at 25°C, remained constant within experimental error over a 15-month interval. However, the biological activity of the residues against Sitophilus oryzae (L.) declined to 78% of the initial value at 3 months, and to 65% at 15 months after application. Inactivation of a proportion of the intact residues is indicated. 相似文献
20.
在黄土高原半干旱雨养条件下以露地种植为对照(CK),设置了4种玉米整秆带状覆盖方式:带状3行(MS3),带状4行(MS4),带状5行(MS5),带状6行(MS6),比较研究了不同带幅对冬小麦产量、土壤水分变化的影响。结果表明:适宜带幅(MS3、MS4)的秸秆带状覆盖能显著改善土壤水分状况并提高冬小麦产量和水分利用效率,MS3、MS4分别较CK增产69.1%、41.3%,水分利用效率提高88.1%、39.1%。MS3与MS4对土壤含水量在不同时期、不同土层均具有增墒和降墒的双重效应,但增墒效应更为突出,全生育期平均分别较CK提高土壤含水量1.00和0.35个百分点。MS3可以显著改善土壤水分在各生育时期各土层的分布情况,其在播种期~越冬期、返青期~孕穗期的供水效果,以及60cm以下土层对60 cm以上土层的水分补给效果均好于其它处理,有利于冬小麦生长、成穗,提高穗粒数,因此MS3更适合黄土高原半干旱雨养地区的冬小麦生产。 相似文献