摘要:

AbstractThe fumigant nematicide, 1,3‐dichloropropene (1,3‐D VL; ‘Telone’ II) and a soluble liquid formulation, 1,3‐D SL were tested in a pineapple field experiment to evaluate the vapor movement of the two formulations in soil gas as well as the movement and persistence of 1,3‐D SL in soil profiles. Prior to planting, 1,3‐D VL (407 kg ha−1) was hand‐injected into the soil in two parallel rows per planting bed to approximate the practice of chisel injection. 1,3‐D SL (407 kg ha−1) was applied with 6 mm of water by drip irrigation through a drip tube in the center of the bed. Post‐plant applications of 1,3‐D SL (113 kg ha−1) were made at three‐month intervals during a two‐crop cycle. 1,3‐D concentrations in soil gas were lower at the plant line in the drip treatment compared with the 1,3‐D VL treatment, owing to differences in application method and fumigant placement. 1,3‐D in the vapor phase reached peak concentrations 24 h after injection in the 1,3‐D VL treatment compared with a peak at 48 h in the drip treatment. Post‐plant applications of 1,3‐D SL resulted in a three‐fold difference in peak 1,3‐D soil gas concentrations between replicate applications, the concentration being inversely related to soil moisture at the time of sampling. Drip application of 1,3‐D SL resulted in a relatively uniform distribution of 1,3‐D across the bed and to a depth of 45 cm. There was no effect of formulation on downward movement of 1,3‐D and persistence in soil profiles sampled two weeks and one month after application. Rainfall which occurred 9 days after pre‐plant 1,3‐D fumigation resulted in leaching of 1,3‐D to a depth of 150 cm in soil profiles. Due to the short half‐life of 1,3‐D, significant penetration of 1,3‐D in the soil was observed

ISSN:0031-613X    

DOI:10.1002/ps.2780430202

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractExperiments with intact cells and submitochondrial fractions ofPythium aphanidermatum(Edson) Fitz. indicated an interference of benzimidazole‐N‐sulfonamides with the NADH‐ or succinate‐driven electron transport system between cytochromesbandc. Comparison withUstilago maydis(DC) Corda andBotrytis cinereaPers. ex Fr. revealed that this effect isOomycetesspecific. The molecular interaction between benzimidazole‐N‐sulfonamides and the mitochondrial cytochromeb/c1complex fromP.aphanidermatumhas been investigated. Binding assays with [14C]52232 RP (dimefluazole) indicated a time‐ and dose‐dependent labelling of two proteins. The molecular mass of one labelled protein and the competition of the binding with antimycin A suggest that benzimidazole‐N‐sulfonamides interact with the Q1‐centre of cytochromeb.Furthermore, experiments with doubly labelled [3H][14C]CGA 323103 revealed a possible irreversible inactivation of theb/c1complex leading to covalent linkage of the dimethylsulfonamoyl moie

ISSN:0031-613X    

DOI:10.1002/ps.2780430203

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractInheritance of resistance to theBacillus thuringiensisBerl. CryIA(b) crystal protein was studied inPlutella xylostellaL. (diamondback moth). A field population 50‐fold more resistant to CryIA(b) than a control susceptible strain was used. Dose‐mortality curves of the resistant population, the susceptible strain and the F1from the two reciprocal crosses were compared. Resistance transmission to the F1was dependent on the sex of the resistant progenitor. Sex ratio of the survivors to high doses of CryIA(b) in the F1of the two reciprocal crosses did not corroborate the preliminary hypothesis of resistance being due to a recessive sex‐linked allele. Since, in a previous work, the loss of CryIA(b) binding capacity of resistant insects had been demonstrated, binding to midgut tissue sections from F1individuals was also analysed. The presence of binding in all of the F1preparations showed that, at least, a recessive autosomal allele was responsible for the loss of binding capacity in the resistant popul

ISSN:0031-613X    

DOI:10.1002/ps.2780430204

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractPesticide movement to subsurface drains was monitored in two typical crop production areas in Germany. Field trials were conducted on two subsurfacedrained soils, a silt loam and a poorly structured sandy soil, under different climatic conditions. Over a period of one year, the drainflow was measured and the drain water was analysed for all applied herbicides.Different leaching behaviour was observed at the two field sites. Following autumn application of pendimethalin and isoproturon to the Soester Börde soil, maximum concentrations of about 62 μg litre−1for isoproturon and 0.7 μg litre−1for pendimethalin were observed in drainflow from this silt loam. The early occurrence of both herbicides in the drain water only two days after application is consistent with fast flow through macropores. In contrast, on the subsurfacedrained sandy soil in Brandenburg, isoproturon did not reach the drains until two months after autumn application and was found at maximum concentrations of only 1.4 μg litre−1; pendimethalin was not detected in the drain water.Pesticide movement after spring application seemed to be of minor importance. At both locations, spring application led to low concentrations of pesticides in the drainflow (pendimethalin<0.01 μ litre−1; metolachlor ⩽ 0.05 μ litre−1; chloridazon ⩽ 0.15 μ litre−1; metamitron ⩽ 0.02 μg litre−1; terb

ISSN:0031-613X    

DOI:10.1002/ps.2780430205

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA field experiment at Cockle Park, Northumberland on a clay loam soil (Dunkeswick series) cropped with winter wheat investigated the effects of drainage and season of application on pesticide movement. Isoproturon, mecoprop, fonofos and trifluralin were applied in two consecutive seasons at normal agricultural rates to three hydrologically isolated plots each of 0.25 ha. Two of the plots were mole‐drained and the third was an undrained control. Surfacelayer flow and drainflow from each plot were monitored at 10‐min intervals. Samples of flow were analysed for pesticides to evaluate transport of applied chemicals from the site. Despite widely differing properties (Koc20–8000 ml g−1,t1/210–60 days), all four pesticides were found in surface‐layer flow and mole drainflow from the site. Maximum concentrations of pesticides in flow ranged from 0.1 to 121 μg litre−1(aqueous phase) and<0.2 to 48 μg litre−1(particulate phase). Over two contrasting seasons, total losses of pesticides in flow followed total amounts of flow and were approximately four and five times larger, respectively, in 1990/91 than in 1989/90. The maximum loss occurred from the undrained plot and was 2.8 g isoproturon (0.45% of that applied). Total losses of autumn‐applied pesticides from an undrained plot were up to four times greater than losses from a mole‐drained plot. Mole drainage decreased movement of pesticides from this slowly permeable soil by reducing the amount of surfacelayer flow. Maximum concentrations of mecoprop and isoproturon in drainflow were 10–20 times larger following spring application than after application in autumn. Bypass flow down soil cracks was an important process by which pesticide was lost from the site, with transport to the drainage system via mole channels (55 cm depth) after less than 0.5 and 6.7 mm net drai

ISSN:0031-613X    

DOI:10.1002/ps.2780430206

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe insecticide abamectin is extracted from soil and animal tissue by supercritical fluid extraction. Supercritical carbon dioxide modified with 9% 2‐methoxyethanol extracted abamectin from soil samples at levels up to 11 ng g−1with greater than 80% efficiency. Recovery at fortification levels of 5 ng g−1were obtainable without the need for clean‐up. Abamectin was also easily extracted from animal tissue at levels of 22ng g−1without interfering coextractives. Extracted abamectin was determined by liquid chromatography of a fluorescent d

ISSN:0031-613X    

DOI:10.1002/ps.2780430207

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractCommercial formulations of flamprop‐M‐isopropyl and formulations of other members of this class of herbicide have always contained an oil adjuvant to increase herbicidal performance. Further increases of performance could be obtained by following the label recommendations to add further quantities of a commercial emulsifiable oil (e.g. ‘Swirl’). Nevertheless it was judged that, in view of current advances in adjuvant research, even greater improvements in herbicidal performance could be obtained with different types of adjuvants.Experimental trials using a cultivated oat (Avena sativaL.) assay under glasshouse conditions to test ranges of surfactants (alkyl aryl, alkyl saccharide, alkylamine and alcohol ethoxylates) and emulsifiable oils (paraffinic/naphthenic, rape seed, transmethylated rape seed) showed that all of these adjuvants were capable of increasing flamprop‐M‐isopropyl activity compared with that of an emulsifiable concentrate formulation containing no adjuvant. Alkylamine and alcohol ethoxylates, with no particular preference for the length of the alkyl chain, but optimum ethylene oxide content of 5 moles and 7–10 moles respectively, were the most efficacious and better than the current emulsifiable oil system. There was no additional benefit from mixture of these two types of adjuvant and an alcohol ethoxylate (‘Dobanol’ 25‐7) was preferred on cost grounds. This adjuvant also gave substantial activity to the otherwise inactive suspension concentrate formulation. Final trials determined that the optimum application rate of ‘Dobanol’ 25–7 was in the range 1000–1500 g ha−1, and this information guided the desi

ISSN:0031-613X    

DOI:10.1002/ps.2780430208

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA 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 fatuaL.) in wheat (Triticum aestivumL.) and barley (Hordeum vulgareL.). 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 ofAvenaspp. was obtained at 300 g AI ha−1with 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 gha−1with ratios of ‘Dobanol’ 25‐7 in the range 2:1 to 4:1 that would achieve high levels of control ofAvenaspp. without un

ISSN:0031-613X    

DOI:10.1002/ps.2780430209

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe following are extended summaries based on posters presented at the 8th International Congress of Pesticide Chemistry (IUPAC), held in Washington, DC, USA, 4–9 July 1994. They are entirely the responsibility of the authors, and do not necessarily reflect the views of the Editorial Board of Pesticide Scienc

ISSN:0031-613X    

DOI:10.1002/ps.2780430210

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0031-613X    

DOI:10.1002/ps.2780430211

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY