bluuebunny/crossref_metadata_2025_split huggingface dataset:
1,3‐dichloropropene distribution in soil when applied by drip irrigation or injection in pineapple culture
Authors: Schneider Randi C. , Green Richard E. , Wolt Jeffrey D. , Loh Rhonda K. H. , Schmitt Donald P. , Sipes Brent S. 
Published: November 2006

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 only when irrigation or rainfall occurred soon after application.
Movement of pesticides to surface waters from a heavy clay soil
Authors: Brown Colin D. , Hodgkinson Robin A. , Rose Derek A. , Syers J. Keith , Wilcockson Steve J. 
Published: November 2006

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 (Koc 20–8000 ml g−1, t1/2 10–60 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 drainage in the two winters.
Further studies in increased sensitivity to N‐phenylanilines in benzimidazole‐resistant strains of Botrytis cinerea and Venturia nashicola
Authors: Ishii Hideo , Josepovits Gyula , Gasztonyi Maya , Miura Tamiko 
Published: November 2006

AbstractThe ring‐substituted N‐phenylanilines, N‐(3‐chlorophenyl)aniline (MC‐1) and N‐(3,5‐dichlorophenyl)aniline (MC‐2) were tested for their antifungal activity against Botrytis cinerea Pers. ex Fr. and Venturia nashicola Tanaka et Yamamoto. In both fungi, increased sensitivity to MC‐1 and MC‐2 was clearly observed in ‘highly carbendazim‐resistant, diethofencarb‐sensitive’ (HR, S) phenotypes. Sensitivity was low in ‘carbendazim‐sensitive, diethofencarb‐resistant’ (S, R) and ‘intermediately carbendazim‐resistant, diethofencarb‐resistant’ (IR, R) strains. On cucumber cotyledons, other strains of B. cinerea, possessing the phenotype ‘highly carbendazim‐resistant, diethofencarb‐resistant’ (HR, R) were not controlled by either MC‐1 or MC‐2. Response to MC‐2 was also examined using random ascospore progenies from V. nashicola crosses. In these progenies, high‐level carbendazim resistance and MC‐2 sensitivity always segregated together. Sensitivity to MC‐2 is controlled by a single gene which is either identical to or very closely linked to one conferring high‐level resistance to carbendazim.
Pyriproxyfen, a novel insect growth regulator for controlling whiteflies: Mechanisms and resistance management
Authors: Ishaaya Isaac , Horowitz A. Rami 
Published: November 2006

AbstractPyriproxyfen, a novel juvenile hormone mimic, is a potent suppressor of embryogenesis and adult formation of the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Dipping of cotton or tomato seedlings infested with 0 to 1‐day‐old eggs in 0.1 mg litre−1 resulted in over 90% suppression of egg hatch of both B. tabaci and T. vaporariorum. Older eggs were affected to a lesser extent. Exposure of whitefly females to cotton or tomato seedlings treated with pyriproxyfen resulted in oviposition of non‐viable eggs. The LC90 values for egg viability of B. tabaci and T. vaporariorum exposed to treated plants were 0.05 and 0.2 mg litre−1, respectively. Treatment of whitefly larvae with 0.04–5 mg litre−1 resulted in normal development until the pupal stage; however, adult emergence was totally suppressed. Second instars of B. tabaci exposed to 5 mg litre−1 pyriproxyfen, excreted honeydew at a level similar to the control level until the fourth instar (pupation), after which a strong reduction was observed. Inhibition of egg‐hatch on the lower surface of cotton leaves was observed when their upper surface was treated with 1–25 mg litre−1, indicating a pronounced translaminar effect. These findings indicate that pyriproxyfen is an efficient control agent of both B. tabaci and T. vaporariorum. The compound has been used successfully for controlling whiteflies in Israeli cotton fields since 1991.Adults of B. tabaci collected from a rose greenhouse and from adjacent cotton fields were monitored during 1991–1993 for their susceptibility to pyriproxyfen. A high level of resistance was recorded in whiteflies collected from a greenhouse after three successive applications of pyriproxyfen. Based on LC50 values, the resistance ratio for egg‐hatch suppression was 554‐fold and, for adult emergence failure, 10‐fold. However, a single treatment of pyriproxyfen in cotton fields during the summer season (according to an insecticide resistance management (IRM) strategy) did not alter appreciably the susceptibility of B. tabaci to this compound. In order to prevent development of resistance, an attempt should be made to restrict its use to one treatment per crop season applied during the peak activity of the pest.Pyriproxyfen can be alternated with other novel compounds such as buprofezin and diafenthiuron for controlling whiteflies in cotton, vegetables and ornamentals as part of integrated pest management (IPM) and IRM strategies. In pyriproxyfen‐ or buprofezin‐resistant strains of B. tabaci or T. vaporariorum, no appreciable cross‐resistance was observed among pyriproxyfen, buprofezin and diafenthiuron.
Urine excretion of pentachlorophenol (PCP) in occupational exposure
Authors: Barbieri Franco , Colosio Claudio , Schlitt Helmut , Maroni Marco 
Published: November 2006

AbstractThe pharmacokinetics of pentachlorophenol (PCP) excretion in urine was examined in four workers exposed to the biocide in the tannery and wood industries. PCP concentration in urine was significantly higher in morning samples than in afternoon or evening samples. This excretion pattern was observed during an exposure of several shifts and following a four‐week holiday period. The estimated half‐life for PCP urine excretion was 10 days. Biological monitoring of occupational exposure to PCP should be carried out by measuring the concentration of the compound in urine collected in the morning or before the workshift.
Synthesis and fungicidal activity of 1,4‐dithiino[2,3‐b]quinoxaline‐2,3‐dicarbonitriles
Authors: Romer Duane R. , Aldrich Brian L. , Pews R. Garth , Walter Richard W. 
Published: November 2006

AbstractA series of eleven 1,4‐dithiino[2,3‐b]quinoxaline‐2,3‐dicarbonitriles was prepared by reaction of 2,3‐dichloroquinoxalines with disodium (2)‐2,3‐dimercapto‐2‐butenedinitrile in N,N‐dimethylformamide. These products were tested for in‐vitro fungicidal activity by a Minimum Inhibitory Concentration (MIC) method. Several of these compounds showed broad‐spectrum fungicidal activity. The activity exhibited by these compounds was greatly dependent upon the substituents of the quinoxaline ring, with the nitro‐substituted derivatives showing the highest levels of antifungal activity. None of the compounds prepared, however, showed fungicidal activity comparable to that of the commercial fungicides screened.
Phytotoxicity of trifluoromethyl‐ and methyl‐substituted dinitroaniline herbicides on resistant and susceptible populations of black‐grass (Alopecurus myosuroides)
Authors: James Elizabeth H. , Kemp Malcolm S. , Moss Stephen R. 
Published: November 2006

AbstractA Petri‐dish assay was used to determine the phytotoxicities of the dinitroaniline herbicides pendimethalin, trifluralin, benfluralin and ethalfluralin, and the methyl‐substituted analogues of the last three herbicides, on susceptible (Rothamsted) and multiple‐herbicide resistant (Peldon) populations of blackgrass Alopecurus myosuroides Huds. The Peldon population showed a high degree of resistance to pendimethalin, which possesses a 3,4‐dimethyl substitution. The two populations were equally sensitive to trifluralin, benfluralin and ethalfluralin which do not possess ring‐methyl groups but contain a 4‐trifluoromethyl group. Substitution of the 4‐trifluoromethyl with a methyl group, as demonstrated by the analogues, reduced phytotoxicity, but to a much greater degree in Peldon than in the Rothamsted population. The study indicates that resistance to pendimethalin in the Peldon population is attributable to an oxidative degradation of the 4‐methyl group, analogous to that which occurs with resistance to chlorotoluron. The lack of cross‐resistance to the other dinitroaniline herbicides appears to be due to the absence of ring‐methyl or other groups which are vulnerable to oxidative degradation, trifluoromethyl groups being particularly resistant to this form of reaction.
Fenbutatin oxide, fate in soil after extensive commercial use in Italy and Spain
Authors: Gray Alan , Dutton Alan J. , Eadsforth Charles V. 
Published: November 2006

AbstractThe long‐term fate of the acaricide, fenbutatin oxide, in soil has been investigated. Residues of the compound and its two principal metabolites have been determined in soil samples obtained from citrus orchards in Italy and Spain where the product had been applied commercially over a period of 6–10 years.The average fenbutatin oxide content in the upper 0–15 cm soil layer ranged from ⩽ 1 mg kg−1 to 5 mg kg−1 in sites receiving single and double applications per year. The residues were located primarily (> 95%) in the top 0–30 cm layer and there was virtually no movement of the compound through the soil to lower depths. Below 0.5 m depths, the sites contained average concentrations of ⩽ 0.01 mg kg−1, the limit of determination. No significant build‐up of residues was observed and the data indicate an approximate half‐life in soil of just less than one year.Residues of the two metabolites, dihydroxy‐bis(2‐methyl‐2‐phenylpropyl)stan‐nane and 2‐methyl‐2‐phenylpropyl stannonic acid, were on average 11% and 16% of the fenbutatin oxide concentration, respectively. As with fenbutatin oxide, there was no significant movement through the soil to lower levels.
The use of computer‐generated electrostatic surface maps for the design of new ‘GABA‐ergic’ insecticides
Authors: Whittle Alan J. , Fitzjohn Stephen , Mullier Graham , Pearson David P. J. , Perrior Trevor R. , Taylor Robin , Salmon Roger 
Published: November 2006

AbstractA computer model was constructed based on the observation that a number of structurally dissimilar compounds gave rise to similar biological activity. Mode of action work confirmed the link. The model was then used to prioritise targets for synthesis and successfully predicted many active series. The major limitation of the model was that it was unable to predict potency or spectrum. It is thought likely that the factors controlling these limitations are linked with LUMO energies, but this hypothesis has not been proven.
Adsorption and ED50 values of five soil‐applied herbicides
Authors: Pedersen Hanne Juul , Kudsk Per , Helweg Arne 
Published: November 2006

AbstractThe soil partition coefficients (Kd values) and ED50 values of carbetamide, isoproturon, propyzamide, trifluralin and pendimethalin were determined on various soil types. Adsorption increased in the order carbetamide < isoproturon < propyzamide < trifluralin < pendimethalin, whereas the influence of soil types on herbicide efficacy increased in the order isoproturon < carbetamide < pendimethalin < trifluralin < propyzamide. The relationship between adsorption and ED50 values of the herbicides was examined by estimating the herbicide concentration in soil water solution. Adsorption and ED50 values on common Danish soil types (0.6% carbon and 12% clay to 2.3% carbon and 4.4% clay) differed by factors of up to three and four, respectively, indicating a possibility of adjusting the herbicide dose according to soil factors.
Occurrence of organochlorine agrochemical residues in Spanish cheeses
Authors: Bentabol Antonio , Jodral Manuela 
Published: November 2006

AbstractA total of 146 samples of different kinds of cheeses produced in Spain were analysed in order to ascertain the specific contamination pattern. The organochlorine compounds studied were those most commonly investigated in previous surveys: α‐HCH, β‐HCH, γ‐HCH (lindane), γ‐HCH, chlordane, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, and the isomers and metabolites of DDT. α‐HCH, β‐HCH, γ‐HCH, chlordane, p,p′, DDT, and p,p′‐DDE were found in more than 76% of samples; p,p′‐DDE and γ‐HCH were the most frequently detected, with frequencies of 100 and 97.9% respectively. γ‐HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, o,p′‐DDT, p,p′‐DDD and o,p′‐DDD were observed at lower frequencies. No residues of endrin were detected in any sample. Insecticides exceeding the maximum residue limits (MRLs) were chlordane, β‐HCH, α‐HCH and γ‐HCH, with 42, 20, eight and six samples respectively. Mean residues of organochlorines found were as follows (μ kg−1 butterfat): α‐HCH = 46.3; β‐HCH = 46.5; γ‐HCH = 54.2; δ‐HCH = 16.9; aldrin = 16.7; dieldrin = 9.7; heptachlor = 15.9; heptachlor epoxide = 14.8; chlordane = 50.2; o,p′‐DDT = 5.1; p,p′‐DDT = 12.4; o,p′‐DDT = 19.6; p,p′‐DDD = 46.7; o,p′‐DDE = 6.9; p,p′‐DDE = 40.7 (.DDT = 55.0).Estimated dietary intakes (EDIs) from cheese consumption were compared to acceptable daily intakes (ADIs) for the pesticides where residues exceeded the MRL. EDIs calculated were in all cases below ADIs, and, therefore, based on the ADIs, there is no health risk involved in the consumption of cheese from Spain arising from organochlorine residues.
Integration of chemical and biological control systems for arthropods: Evaluation in a multitrophic context
Authors: Wright Denis J. , Verkerk Robert H. J. 
Published: November 2006

AbstractThe methods used to evaluate and categorise the effects of pesticides on beneficial arthropods are reviewed, including the potential significance of indirect, ‘sub‐lethal’ activity and the importance of bioavailability of pesticides under semi‐field or field conditions. Interspecific and intraspecific differences in the susceptibility of natural enemies (parasitoids and predators) to pesticides are considered, including the use of resistant strains in Integrated Pest Management (IPM) systems. The potential impact of pesticide resistance in the target pest on its natural enemies is also discussed. The need to assess the influence of the host plant/cultivar on the efficacy of pesticides for use in integrated control programmes (ditrophic effects) and of the possible effects of such chemicals on host plant/cultivar‐pest‐parasitoid systems (tritrophic effects) are then described with specific reference to the diamondback moth and key endolarval parasitoids. Finally, the potential for manipulation of tritrophic interactions to enhance parasitism by application of low doses of toxicants is demonstrated.
Chronic effects of dimethoate on the reproductive potential of the fresh‐water teleost, Clarias batrachus
Authors: Begum Ghousia , Vijayaraghavan Shantha 
Published: November 2006

AbstractIn a study of the fresh‐water teleost Clarias batrachus L., fish were exposed to a commercial 300 g litre−1 EC formulation (of dimethoate at 10.8 mg AI litre−1) for a period of six months extending over prespawning, spawning and postspawning phases of the annual reproductive cycle. A parallel group of fish without dimethoate served as control. Significant reduction in the fecundity pattern of exposed fish was noticed throughout the experimental period. The gonadosomatic indices of both male and female exposed fish were reduced when compared with the control fish. The reduction continued until the termination of the experiment. It was inferred from the present study that, at this level, this pesticide affects the reproductive potential of this fish.
Transformation of aldicarb sulfoxide and aldicarb sulfone in four water‐saturated sandy subsoils
Authors: Smelt Johan H. , Van De Peppel‐Groen Ariette E. , Leistra Minze 
Published: November 2006

AbstractThe transformation of aldicarb sulfoxide and aldicarb sulfone was studied in incubations with water‐saturated subsoils under simulated field conditions at 10°C. The subsoils were collected at four locations from beneath the water table at a depth of 2.5 to 3.5 m. In three of the subsoils, the half‐life of sulfoxide, incubated at concentrations of 0.14‐0.17 mg litre−1, ranged from 0.7 to 2.8 years. At higher concentrations (8‐13 mg litre−1), its half‐life ranged from 3.4 to 6.4 years. At the lower concentration, a large fraction of sulfoxide was transformed into sulfone. The rates of transformation of the sulfone at the lower concentration in the three subsoils corresponded to half‐lives of 3.3 to 8.1 years, but in only one subsoil was a significant transformation rate (half‐life 6.7 years) measured at the higher concentration during the 2.3‐year incubation period. The half‐lives at the lower concentrations were more like those in field studies, and perhaps would still underestimate transformation rates under field conditions. After a year, 2.5‐15% of the higher sulfoxide and sulfone doses had been trapped as [14C] carbon dioxide. In the fourth subsoil, with more anaerobic conditions, the half‐life of sulfoxide at both concentrations was less than 0.02 year and that of sulfone was about 0.04 year. Four or five radio‐labelled transformation products could be traced in this subsoil and about half of the dose of both compounds was trapped as [14C] carbon dioxide.
Metal chelate molluscicides: The redistribution of iron diazaalkanolates from the gut lumen of the slug, Deroceras reticulatum (Müller) (Pulmonata: Limacidae)
Authors: Clark Suzanne J. , Coward Nicola P. , Dawson Glenn W. , Henderson Ian F. , Martin Andrew P. 
Published: November 2006

AbstractTwo related iron chelates, one toxic to slugs by ingestion, the other not, were introduced into the foregut of D. reticulatum. The subsequent movement and redistribution of the metal within the slug tissues was studied by labelling the chelates with the radioactive isotope 55Fe. In slugs which survived treatment approximately half of the 55Fe was voided in faeces. The iron retained became unevenly distributed, the highest concentration occurring in the digestive gland, irrespective of the chelate used. At high doses, slugs treated with tris(1‐oxo‐1,2‐diazabutan‐2‐oxido)Fe(III) were fatally poisoned while those treated with the homologue, tris(1‐oxo‐1,2‐diazaoctan‐2‐oxido)Fe(III) were not. Slugs killed by the toxic chelate consistently contained proportionally less iron in the digestive gland and proportionally more in the body wall and reproductive system. Dosing slugs already killed by carbon dioxide asphyxiation gave a similar pattern, suggesting that the greater mobility of the iron from the toxic chelate was not a function of the slugs' metabolism.
Management of microbial processes in cattle‐dipping vats containing coumaphos
Authors: Karns Jeffrey S. , Ahrens Elmer H. , Davey Ronald B. , Shelton Daniel R. 
Published: November 2006

AbstractThe organophosphate veterinary insecticide coumaphos [O‐3‐chloro‐4‐methyl‐2‐oxo‐2H‐chromen‐7‐yl O, O‐diethyl phosphorothioate] is used by the Animal and Plant Health Inspection Service of the United States Department of Agriculture in its program designed to prevent re‐entry of the southern cattle tick (Boophilus microplus Can.) and the cattle tick (B. annulatus Say) into the United States from Mexico. Large amounts of waste acaricide are generated annually in this program. One event that triggers disposal of coumaphos dips is the accumulation of potasan [O, O‐diethyl O‐4‐methyl‐2‐oxo‐2H‐chromen‐7‐yl phosphorothioate]. This process was shown to occur under anaerobic conditions and to be inhibited by mercury ions, indicating that anaerobic micro‐organisms were responsible for a reductive dechlorination. Maintaining coumaphos suspensions at pH < 7 prevented the reductive dechlorination of coumaphos and left a suspension that was amenable to disposal by biodegradation. A field trial on an 11000‐litre capacity coumaphos dipping vat demonstrated the applicability of using acid to extend the life of coumaphos solutions and of biodegradation for the disposal of spent material.
Improved method for the analysis of imazapyr in soil
Authors: Helling Charles S. , Doherty Michael A. 
Published: November 2006

AbstractA method for the analysis of imazapyr [2‐(4‐isopropyl‐4‐methyl‐5‐oxo‐2‐imidazolin‐2‐yl)nicotinic acid] residues in tropical and temperate soils was developed. Imazapyr residues, extracted from soil with ammonium hydrogen carbonate and cleaned‐up by centrifuging, anion‐exchange solid‐phase extraction (SPE), pH adjustment, and C18 SPE, were determined by HPLC. Recoveries from soils from Hawaii (Halii sandy clay loam), Texas (Houston Black clay), and Maryland (Codorus loam), USA, fortified with imazapyr (0‐5 μg g−1 soil) and equilibrated for 12‐18 h, were 99(±3)%, 104(±4)% and 89(±2)%, respectively. Recoveries were independent of fortification level, but dependent upon soil type. Methods previously described in the literature produced imazapyr recoveries of less than 60% with Halii soil. This improved method has a limit of detection of 5 ng g−1 (equivalent to or better than other methods) and affords higher recovery of imazapyr residues from tropical soil.