bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental fate of mineral, vegetable and transesterified vegetable oils
Authors: Cornish Alex , Battersby Nigel S. , Watkinson Robert J. 
Published: November 2006

AbstractVegetable oils, synthetic esters (including transesterified oils) and mineral oils are the main classes of oil used in pesticide formulations. Biodegradation is a major route for the removal of oils from soil systems. Most of the oils used in pesticide formulations are degraded substantially in the laboratory tests that are used to assess aquatic biodegradability. The susceptibility of different oils to biodegradation can be explained in terms of the metabolic capacity of common microorganisms.Fewer soil biodegradability tests have been carried out with oils, but the available data suggest that the mode of degradation is not very different from that in aquatic systems. Supplements of inorganic nutrients (in particular nitrogen) are needed to stimulate microbial activity in soils containing the high concentrations of oil that can be encountered in the event of a spill. However, oils are applied at such low rates in pesticide form illations (maximum of 5g oil m− soil) that nutrient availability is unlikely to affect the rate of biodegradation in the field.
The plasma membrane as a barrier to herbicide penetration and site for adjuvant action
Authors: Wade Brian R. , Riechers Dean E. , Liebla Rex A. , Wax Loyd M. 
Published: November 2006

AbstractAdjuvants are traditionally thought to exert their main effect on the cuticle or spray droplet to enhance foliar‐applied herbicide penetration. However, considerable evidence exists indicating that the plasma membrane is a barrier to intracellular penetration of herbicides and a site of action for adjuvants. Surfactants may penetrate through the cuticle and into the region of the plasma membrane. Insertion into the membrane causes a general “ loosening” to provide greater penetration by highly polar herbicides such as glyphosate. Weak acid herbicides typically have a lipophilic moiety and, therefore, can move more easily through the membrane but the rate and accumulation is dependent on pH conditions across the membrane. Ammonium salts have been shown to affect the pH of the apoplast in a manner which allows faster penetration and greater accumulation of weak acid herbicides. Examination and understanding of the plasma membrane as a barrier to herbicide penetration will aid in defining the mechanisms of adjuvant action and improve the efficiency of agrochemical use.
Fungicidal activity of a series of chloroacetylanilidophosphonates
Authors: Ha Hyun‐Joon 
Published: November 2006

AbstractNine diethyl chloroacetylanilidomethylphosphonates and ten diethyl α‐(chloroacetylanilido)benzylphosphonates were prepared by N‐chloroacetylation of the corresponding diethyl anilinomethyl‐ and anilinobenzylphosphonates. These were tested for antifungal activity against six phytopathogenic fungi. Most of the compounds showed moderate protective properties. No significant difference in activity was observed for compounds with an extra aryl ring substituent on the methylene group of the backbone. Compounds with electron‐withdrawing substituents, especially chlorine, on the aniline site (R1) showed higher fungicidal activity than the other compounds with electron‐donating groups as substituents.
Effects of wind direction, wind speed and travel speed on spray deposition
Authors: Nordbo Ebbe , Kristensen Kristian , Kirknel Erik 
Published: November 2006

AbstractDeposition variability from a conventional field sprayer, and effects of wind and travel speed were measured by collecting on small artificial targets in the swath. Whilst deposition on 0.1‐m2 plots varied by a factor of 3, deposition on single vertical targets typically varied by a factor of 10 and on horizontal targets by a factor of 6. Distinct transversal deposition patterns appeared according to wind direction. The quantity and structure of variability was compared with wind speed and turbulence intensity, but few significant trends were found. Deposition on vertical targets was enhanced by increasing wind speed or increasing travel speed, whilst effects on horizontal targets were inconsistent.
HPLC determination of fenoxaprop and fenoxaprop‐ethyl in different soils
Authors: Celi Luisella , Négre Michéle , Gennari Mara 
Published: November 2006

AbstractThis paper describes a method for the determination of fenoxaprop ethyl and fenoxaprop residues in four soil types using two extraction procedures: extraction with 0.1 M hydrochloric acid/methanol, partitioning with dichloromethane and extraction with ethyl acetate. The extracts were purified on florisil or alumina cartridge. The analyses were performed by reverse phase HPLC with UV detection at 280 nm.The best results in terms of recovery, clean‐up efficiency and independence of soil characteristics were obtained with the combination ethyl acetate extraction alumina clean‐up. Under these conditions, the recoveries were higher than 70 % and the detection limit was 0.02 mg kg−1 soil.
Influence of diammonium sulfate and other salts on glyphosate phytotoxicity
Authors: Nalewaja John D. , Matysiak Robert 
Published: November 2006

AbstractDiammonium sulfate is commonly used as an adjuvant with glyphosate, but reports vary regarding its effect on weed control, and its possible function in enhancing glyphosate phytotoxicity is not fully understood. Several experiments were conducted in the glasshouse to determine glyphosate phytotoxicity to various species as influenced by diammonium sulfate in distilled water and in the presence of antagonistic salts. Diammonium sulfate overcame sodium hydrogen carbonate, calcium chloride, and 2,4‐D antagonism of glyphosate phytotoxicity to wheat (Triticum aestivum L.). Sulfate anions were important for overcoming calcium antagonism, possibly by forming calcium sulfate. Scanning electron micrographs of spray droplets of glyphosate with calcium chloride and diammonium sulfate indicated the presence of crystals, presumed to be calcium sulfate, that were independent of the glyphosate deposit. Diammonium sulfate may also provide ammonium ions to form effective glyphosate‐ammonia complexes rather than less effective calcium, sodium, diethylamine, or other cation complexes. Diammonium sulfate also may influence susceptibility to glyphosate by affecting herbicide absorption into foliage of certain species. Glyphosate phytotoxicity to sunflower (Helianthus annuus L.) was increased whereas phytotoxicity to kochia [Kochia scoparia (L.) Schrad.] and soybean [Glycine max (L.) Merr.] was reduced by diammonium sulfate applied in the absence of antagonistic salts; diammonium sulfate apparently has several functions as an adjuvant with glyphosate.
Organosilicone surfactants as adjuvants for agrochemicals
Authors: Stevens Peter J. G. 
Published: November 2006

AbstractThe literature has been reviewed and 160 references are presented to provide an overview of organosilicones as adjuvants for agrochemicals. Early studies (1973–1981) elucidated the special properties of these compounds, notably their extreme spreading and, by virtue of the exceptionally low surface tensions of their aqueous solutions, the ability to induce infiltration of spray formulations into foliage via stomata. Subsequent research at the New Zealand Forest Research Institute explored these and other properties in‐depth, and demonstrated that they enabled the herbicide glyphosate to be used as a cost‐effective alternative to 2,4,5‐T for the control of forest scrubweeds. As a result, in 1985, ‚Silwet’︁ L‐77 was the first organosilicone adjuvant to be commercialised, and various other products have subsequently been introduced. The chemistry and synthesis of these organosilicones have been detailed. A mechanistic approach has been adopted to consider the effects of the distinctive properties of organosilicones in each of the processes involved in spray application of agrochemicals. Commencing with spray formulation, the topics of foaming, hydrolytic stability and interactions with coformulants are discussed. Progressing to spray application, consideration is given to the effects of organosilicones on atomisation and impaction (wetting, adhesion/reflection, spreading, retention/run‐off), and the resultant influences on the activity of protectant agrochemicals. An assessment of the use of organosilicones with systemic agrochemicals includes examination of effects on foliar uptake, via both cuticular and stomatal pathways, and the rainfastness which the latter provides. Also considered is the physiological behaviour of organosilicones, specifically phytotoxicity and effects on translocation of active ingredients. The current and potential future use of organosilicones with herbicides, foliar nutrients, growth regulators, insecticides and fungicides is discussed, as is the specificity of their effects. Additionally, the potential application of organosilicone chemistry to adjuvant classes other than the spreader/penetrant type investigated to date is considered. Finally, the issues of registration, handling hazards, both toxicological and chemical, and environmental impact are discussed. The literature reviewed demonstrates the sound science base on which this novel class of organosilicone adjuvant chemistry rests.
The influence of a fatty amine surfactant on foliar absorption and translocation of the trolamine salt and iso‐octyl ester of 2,4‐D
Authors: de Ruiter Hans , Straatman Kees , Meinen Esther 
Published: November 2006

AbstractThe influence of the surfactant ‚Armoblen’︁ 600 (tallow amine block polymer containing a block of polymerized propylene oxide groups (12PO) and a block of polymerized ethylene oxide groups (5EO)) on the foliar absorption and translocation of 2,4‐dichlorophenoxyacetic acid trolamine salt (2,4‐D TR) and 2,4‐dichlorophenoxyacetic acid iso‐octyl ester (2,4‐D IOE) was investigated. Absorption and translocation were monitored for 48 h after application. During this period, without surfactant the leaves of black nightshade (Solanum nigrum L.) absorbed 2.4 times more 2,4‐D IOE than 2,4‐D TR whereas pea leaves (Pisum sativum L.) absorbed 1.3 times more 2,4‐D IOE than 2,4‐D TR. Pea leaves absorbed more of both compounds than did those of black nightshade. Addition of surfactant (5 g litre−1) enhanced the absorption of 2,4‐D TR by black nightshade (4.8‐fold after 48 h) and pea (1.7‐fold after 48 h) but reduced the absorption of 2,4‐D IOE. Without surfactant the absorption of 2,4‐D TR and 2,4‐D IOE was not affected by drying of the drops. Addition of surfactant enhanced absorption of 2,4‐D TR after the drops had dried. Translocation of 2,4‐D TR in black nightshade and in pea, expressed as percentage of the amount absorbed, was reduced by the presence of surfactant. At the end of the observation period this reduction was no longer observed. The translocation efficiency of 14C from 2,4‐D IOE was not influenced by the surfactant. The effects of the surfactant are discussed in relation to its possible mode of action.
Effects of monodisperse alcohol ethoxylates on mobility of 2,4‐D in isolated plant cuticles
Authors: Schönherr Jörg 
Published: November 2006

AbstractEffects of monodisperse ethoxylated n‐alcohols on the mobility of 2,4‐dichlorophenoxyacetic acid (2,4‐D) in cuticular membranes isolated from pear (Pyrus communis L.) and bitter orange (Citrus aurantium L.) leaves, and from green pepper (Capsicum annuum L.) and tomato (Lycopersicon esculentum L.) fruits were measured. The surfactants were of the type C1Ej, where i is the number of carbon atoms of the alcohol, j is the number of ethylene oxide groups and i = 2j. Surfactant effects on mobility increased with time and were inversely proportional to the mobility of 2,4‐D in cuticles prior to surfactant treatment. C4E2 was barely effective. C6E3, C8E4 and C10E5 were the most effective surfactants, as they increased the mobility of 2,4‐D by 15‐ to 20‐fold and the effects were established very rapidly. As the molecular weights of the surfactants increased, their effects decreased and the time‐dependence of effects became more pronounced. Response (susceptibility) of cuticles to surfactant treatment varied among plant species and increased in the order bitter orange < tomato < pear < pepper. Surfactant effects did not correlate with HLB or with cuticle‐water partition coefficients of surfactants tested. It is argued that penetration of surfactants into cuticles is a prerequisite for increasing 2,4‐D mobility and that effects should be proportional to the surfactant concentration in the cuticles. Since rates of foliar penetration are proportional to solute mobilities in cuticles it is expected that the surfactants that were most effective in this study would be suitable accelerator adjuvants for systemic pesticides.
Antagonism of the foliar uptake of glyphosate into grasses by organosilicone surfactants. Part 1: Effects of plant species, formulation, concentrations and timing of application
Authors: Gaskin Robyn E. , Stevens Peter J. G. 
Published: November 2006

AbstractRadiolabelled glyphosate was used to investigate the antagonistic effects of an organosilicone surfactant, ‚Silwet’︁® L‐77™, on the foliar uptake of the formulated herbicide into four grass species, over a 24‐h time‐course. While the effect of L‐77 addition was generally to increase the initial rate of uptake of glyphosate, thereafter the rate was slowed or even halted, such that an overall decrease in uptake was evident as early as 4 h after application in one of the species tested. Further extensive studies on wheat investigated L‐77 effects on uptake of the herbicide as both the pure mono‐isopropylammonium salt, and as the formulated product containing a tallow amine polyethoxylate surfactant. The addition of L‐77 initially increased, but after 1 h reduced the rate of glyphosate uptake, regardless of formulation. There was no evidence that antagonism resulted from any surfactant interaction between the organosilicone adjuvant and the tallow amine co‐formulant. Antagonism was directly related to the concentration of L‐77, and inversely related to that of the formulated herbicide and of its tallow amine co‐formulant. Applied prior to glyphosate application, L‐77 reduced the amount of herbicide in the foliage, and failed to increase substantially the initial rate of uptake. When applied after the a.i., instant enhancement of glyphosate uptake took place with some stomatal infiltration observed, but thereafter no significant cuticular penetration occurred. The mechanisms by which L‐77 could interfere with the cuticular penetration of glyphosate are discussed in light of these results.
Effect of organosilicone‐based adjuvants on herbicide efficacy
Authors: Singh Megh , Mack Robert E. 
Published: November 2006

AbstractLaboratory and field experiments were conducted to evaluate the efficacy of the post‐emergence herbicides, fluazifop‐P‐butyl, glyphosate‐isopropyl‐ammonium, paraquat, and glyphosate‐trimesium (sulfosate) as influenced by organosilicone‐based adjuvants, ‚Dyne‐Amic’︁ and ‚Kinetic’︁. Conventional adjuvants ‚Agri‐Dex’︁ and ‚Induce’︁ were included in all experiments for comparison. The experimental plots were naturally infested with bahiagrass, camphorweed, common lambsquarters, Florida pusley, Jerusalem oak, hairy beggarticks, pigweed, and teaweed. Herbicides were applied alone or in combination with ‚Dyne‐Amic’︁, ‚Kinetic’︁, ‚Agri‐dex’︁, or ‚Induce’︁ using a tractor‐mounted boom sprayer. ‚Dyne‐Amic’︁ (2.5 ml liter−1) was as effective as ‚Agri‐dex (10 ml liter−1) in increasing the efficacy of herbicides on grass and broadleaf weeds studied. ‚Kinetic’︁ at 2.5 ml liter−1 was as effective as ‚Induce’︁ at 2.5 ml liter−1 in increasing the efficacy of herbicides on the weeds studied. Paraquat tank‐mixtures with the pre‐emergence herbicides bromacil and diuron were more effective when applied at a spray volume of 280 liter ha−1 than at 140 liter ha−1. Fluazifop‐P‐butyl and glyphosate‐isopropylammonium were more effective at 186 than at 93 liter ha−1. Addition of ‚Kinetic’︁ or ‚Induce’︁ to the herbicide spray solution had no effect on pH, but fluazifop‐P‐butyl reduced pH to 5.1 or increased it to 7.7 when added to the 93 and 186 liter ha−1 preparations, respectively. Glyphosate‐isopropylammonium reduced pH to 5.0 at the lower, but had little effect on pH at the higher rate. Reduction in static surface tension and contact angle was greater with organosilicone‐based adjuvants than with conventional adjuvants.
Feeding behavior of Plutella xylostella and Leptinotarsa decemlineata on leaves treated with Bacillus thuringiensis and esfenvalerate
Authors: Hoy Casey W. , Hall Franklin R. 
Published: November 2006

AbstractStudies were conducted to examine interactions between esfenvalerate and Bacillus thuringiensis Berl. in their effects on feeding behavior of larvae of Plutella xylostella L. and Leptinotarsa decemlineata Say. Droplets containing esfenvalerate, B. thuringiensis, the two in combination, and water controls were individually applied to leaf disks. Third‐instar P. xylostella larvae were allowed to feed for 24 h on cabbage disks and third‐instar L. decemlineata larvae were allowed to feed for approximately 18 h on potato leaf disks. For each insect species and each treatment, the proportion of leaf area removed during the feeding period was regressed on the proportion of droplets removed during that period to test for avoidance of droplet residues. No significant differences were found between treatments in these regressions for L. decemlineata. In contrast, B. thuringiensis, either alone or in combination with esfenvalerate, significantly affected the relationship of leaf and droplet consumption for P. xylostella. No evidence of individual droplet avoidance, i.e. a consistently greater proportion of leaf than droplets consumed, was found for any of the treatments. Proportions of leaf consumed and proportions of droplets consumed were compared among treatments to test for effects on feeding rate. B. thuringiensis significantly reduced feeding rate, both alone and in combination with esfenvalerate for P. xylostella and alone for L. decemlineata. We found no statistically significant differences in feeding rate due to esfenvalerate. The species studied can be expected to consume the same amount of B. thuringiensis whether it is mixed with esfenvalerate or not, whereas esfenvalerate dose by ingestion would be reduced if it were mixed with B. thuringiensis.
A study of the possible interconversion of hexachlorocyclohexane stereoisomers on chickpea
Authors: Gopal Madhuban , Mukherjee Irani 
Published: November 2006

AbstractA field trial was conducted to study (i) whether there is interconversion of stereoisomers of hexachlorocyclohexane (HCH) on a plant and (ii) the rate of dissipation of lindane on chickpea in a sub‐tropical climate. The lack of formation of the beta and delta isomers on application of pure alpha‐ or gamma‐HCH showed that these stereoisomers of HCH did not interconvert on chickpea. The residues of the alpha and gamma isomers dissipated rapidly on chickpea leaves with half‐lives of three and four days respectively.
A comparative study of carbofuran metabolism in treated and untreated soils
Authors: Talebi Khalil , Walker Colin H. 
Published: November 2006

AbstractSoils which have been pretreated with carbofuran can degrade the insecticide more rapidly than untreated soils, with a consequent loss of efficacy. In laboratory studies, soils pretreated with carbofuran were found to degrade the chemical more rapidly than soils which were not so pretreated. When pretreated soils were sterilised, the rate of carbofuran degradation was much reduced, indicating that most of it was due to microbial action. Incubation of pretreated soil with [phenyl‐U‐14C]carbofuran led to the rapid disappearance of the parent compound (3 % left after seven days). Most of the 14C was accounted for as bound residue after seven days, whilst smaller amounts were recovered as carbon dioxide, 3‐hydroxycarbofuran, 3‐ketocarbofuran, and an unknown metabolite. Incubation of pretreated soil with [carbonyl‐14C]carbofuran led to rapid loss of the parent compound and the recovery of 73% of 14C as carbon dioxide by five days.Most of the bound 14C (>90%) arising from [phenyl‐U‐14C]carbofuran treatment of pretreated soil was extracted by 1 M sodium hydroxide and about half of the extracted 14C was precipitated with ‘humic acids’ after acidification. These and other results suggest that the major metabolic route for carbofuran in pretreated soils involves hydrolysis of the ester bond leading to (1) release of carbofuran phenol which rapidly binds to soil organic matter and, (2) release of the carbonyl moiety which quickly degrades to generate carbon dioxide.
Control of Spodoptera spp. using ULV formulations of the acylurea insect growth regulator, flufenoxuron: Field studies with Spodoptera exempta and effect of toxicant concentration on contact activity
Authors: Fisk Tanya , Cooper Jerry , Wright Denis J. 
Published: November 2006

AbstractField trials in Kenya showed that an ultra‐low‐volume (ULV) application of flufenoxuron (25 g a.i. litre−1; 1–0 litre ha−1) gave consistently good control of late‐instar larvae (L4‐L6) of the armyworm, Spodoptera exempta Walk. Flufenoxuron gave equivalent or greater control of S. exempta than did cypermethrin (24 g a.i. litre−1; 1–0 litre ha−1) from 96 h after ULV application. While initial (24–48 h) levels of larval mortality were greater with cypermethrin, many larvae treated with flufenoxuron showed signs of incomplete moulting after 48–72 h and would have been unable to feed normally. Laboratory spray bioassays with L3 Spodoptera littoralis suggested that the ULV formulation of flufenoxuron was most active at 25 g a.i. litre−1 when compared with higher (50 g) or lower (6.25 and 12.5 g a.i. litre−1) rates. Topical application studies with ULV formulations containing [14C]flufenoxuron showed that the accumulation of pesticide by L3 S. exempta over 1–4 h was consistently greater in larvae treated with 25 g than with 12.5 g flufenoxuron litre−1 and while initially lower, accumulation of pesticide appeared to be greater in larvae treated with 25 g than with 50 g flufenoxuron litre−1 after 2–4 h. The potential of ULV formulations of flufenoxuron for control of S. exempta is discussed.
Concurrent events in the uptake by insects of cypermethrin from a microemulsion formulation
Authors: Lankford William , Dawson Bernard 
Published: November 2006

AbstractChanges in formulation composition at the site of in‐vivo applications of an oil‐in‐water cypermethrin microemulsion have been determined on American cockroaches (Periplaneta americana). Surface washes of 0.6‐μl deposits on femur cuticle recovered decreasing amounts of radio‐labelled diluent water, toluene and cypermethrin with time. After 30 min, only cypermethrin (22.5 % w/w initial dose) could be removed in significant amounts. Extraction of cuticle underlying the site of application indicated similar but independent, patterns of initially increasing levels followed by a decline from the maximum, for all three compounds.Recoveries of formulants in the surface washes were utilised to describe the post‐application nature of the microemulsion deposit as provided by the formulation phase diagram. The initial and most rapid movement of cypermethrin away from the surface deposit apparently took place via the intact oil‐in‐water microemulsion. Some 6 min after application, the deposit entered a viscoelastic gel phase with no further phase change indicated.