bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non‐target effect of herbicides: I. effect of glyphosate and hexazinone on soil microbial activity. Microbial population, and in‐vitro growth of ectomycorrhizal fungi
Authors: Chakravarty P. , Chatarpaul L. 
Published: November 2006

AbstractThe effects of two herbicides, glyphosate (as a 359 g litre−1 SL) and hexazinone (as a 50gkg−1 granule) on soil microbial population, carbon dioxide evolution, and in‐vitro growth of five species of ectomycorrhizal fungi were investigated. Glyphosate at 0–54 and 3.23 kg a.i. ha−1 and hexazinone at 1. 2 and 8 kg a.i. ha−1 did not reduce soil microbial population or carbon dioxide evolution in the long term (6 months). However, there was a significant short‐term (2 months) effect of glyphosate on both fungal and bacterial counts at the 0.54 kg ha−1 treatment. In in‐vitro tests, Cenococcum graniforme. Hebeloma crustuliniforme and Laccaria laccata were more susceptible to both herbicides than was Suillus tomentosus. which was, in turn, more susceptible than Paxillus involutus. The growth of all five ectomycorrhizal fungi was significantly reduced when subjected to concentrations above 50 μl formulation litre−1 (glyphosate) or 50 μg formulation litre−1 (hexazinone).
Non‐target effect of herbicides: II. The influence of glyphosate on ectomycorrhizal symbiosis of red pine (Pinus resinosa) under greenhouse and field conditions
Authors: Chakravarty P. , Chatarpaul L. 
Published: November 2006

AbstractThe effects of the herbicide glyphosate [N‐(phosphonomethyl)glycine]on seedling growth of Pinus resinosa and on the ectomycorrhizal development of the symbiotic fungus Paxillus involutus were investigated under greenhouse and field conditions. Glyphosate at 0–54 and 3–23 kg ha−1 did not reduce seedling growth or ectomycorrhizal development under greenhouse conditions. There was no seedling mortality due to glyphosate treatment at either rate. Under field conditions, seedling growth of P. resinosa and ectomycorrhizal development of P. involutus were not affected by the above rates. Seedlings (46–48%) failed to survive in non‐glyphosate‐treated plots, presumably because of weed competition, whereas all survived in glyphosate‐treated plots. All the non‐mycorrhizal seedlings were colonized bv indigenous mvcorrhizal fungi within 2 months after planting in both control and glyphosate‐treated plots. The injection rates varied from 74–86 %.
Effect of 4‐amino‐6‐methyl‐3‐phenylamino‐l,2,4‐triazin‐5(4H)‐one on the lignification process catalysed by peroxidase from lupin (lupinus albus)
Authors: Muñoz Romualdo , Martinez‐Martinez Antonio , Ros‐Barcelo Alfonso , Pedreño Ma Angeles 
Published: November 2006

AbstractThe molecular action of herbicides with a triazine structure, such as atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazine) and metribuzin (4‐amino‐6‐tert‐butyl‐3‐methylthio‐1,2,4‐triazin‐5(4H)‐one), has been related to their inhibition of the electron carrier system between chloroplastic photosystems II and I.This report provides evidence that 4‐amino‐6‐methyl‐3‐phenylamino‐1,2,4‐triazin‐5(4H)‐one, a recently synthesised triazine, structurally analogous to metribuzin, causes a powerful inhibition of the cell‐wall lignification catalysed by peroxidase from lupin. The two reactions involved in this lignification process are: oxidative polymerisation of coniferyl alcohol and the generation of hydrogen peroxide at the expense of NADH oxidation.
The uptake, excretion and metabolism of the acylurea insecticide, flufenoxuron in spodoptera littoralis larvae, by feeding and topical application
Authors: Clarke Barry S. , Jewess Philip J. 
Published: November 2006

AbstractFlufenoxuron is an acylurea insecticide which inhibits chitin synthesis. Its uptake, excretion and metabolism in larvae of Spodoptera littoralis have been measured. Larvae fed on a leaf disc sprayed at an application rate equivalent to 50 g ha−1rapidly absorbed a maximum of 20% of ingested flufenoxuron, the remainder being voided in the frass. Excretion of absorbed compound was slow, with a 50% excretion time of approximately 20 h. Flufenoxuron was equally effective as an insecticide by topical application or ingestion. Following topical application, a total of 11% of the dose had penetrated into the body within 24 h. Of this 11%, half had travelled to the gut so that the rest of the body tissues contained no more than 6% of the toxicant dose. The concentration of flufenoxuron in the body tissues was maintained for at least 24 h, the surface residue probably acting as a reservoir. The compound was metabolically quite stable. Following topical application the 6 % of the applied dose which was absorbed into the body was still 92% as unchanged flufenoxuron 24 h after application. The enhanced toxicity of flufenoxuron to S. littoralis compared with earlier acylureas can probably be attributed to its slower metabolism and reduced excretion.
Chemical and physico‐chemical characterization of wettable powder formulations containing copper
Authors: Galoux Michel , Bernes Albert 
Published: November 2006

AbstractEleven different commercial wettable powder formulations containing copper have been examined using standard CIPAC recommended techniques to determine the best chemical and physico‐chemical criteria for quality. This approach has allowed the setting‐up of a specification that retains only the essential criteria of quality control required for the official approval of a product of this type in Belgium.
Uptake by tomato plants of the herbicide [14C] 2,4‐D‐butyl in the vapour phase
Authors: Breeze Victor G. 
Published: November 2006

AbstractUptake of [14C‐phenyl]2,4‐D‐butyl by 4‐ to 6‐week‐old tomato plants was measured for vapour concentrations in the range 0.3–19 ng litre−1, for an exposure period of 4 h. Calculation of boundary layer thicknesses at the surface of the leaves, and depletion of the vapour concentration due to uptake by the plants, suggested that the plants experienced concentrations very close to the nominal values. Relationships between external vapour concentration and plant uptake, expressed in terms of fresh weight, leaf area, or on a whole plant basis, were linear in all cases. Twenty‐four hours after the commencement of exposure, leaves contained 63–93% of the total herbicide in the plant; the proportion retained by the leaves was greater at low vapour concentrations. The largest amount of herbicide was present in leaves from the mid‐position on the stem, but in terms of leaf area, the amount was greatest in leaves at the apex and decreased basipetally. It is not known whether this was due to a greater uptake rate per leaf area at the apex, or to translocation. As visible symptoms of phytotoxicity usually develop at the apex, both of these processes, together with the preferential retention of herbicide in leaves at low vapour concentrations, may all contribute to the development of vapour damage.
Effect of the fungicide imazalil on hepatic microsomal cytochrome P‐450 and cytochrome P‐450 dependent activities in the Bobwhite quail (Colinus virginianus)
Authors: Lavrijsen Karel , Van Houdt Jos , Van Dyck Dirk , Meuldermans Willem , Heykants Jos 
Published: November 2006

AbstractBobwhite quails were treated with imazalil for 8 weeks. The fungicide was given admixed in the food at 0, 100, 300, 500 and 1000 mg kg−1. Even at the highest dose tested, imazalil did not affect the liver weight or the hepatic microsomal protein content. In treated quails, no significant induction of cytochrome P‐450 or NADPH‐cytochrome c‐reductase activity was observed. Furthermore, imazalil did not induce or inhibit 7‐ethoxyresorufin or 7‐ethoxycoumarin O‐deethylase in quail microsomes. Only a slight but significant increase by 35% and 49% in aniline hydroxylase activity was measured for the 500‐ and 1000‐mg kg−1 dose levels, respectively. After a drug‐free period of one week, aniline hydroxylase activity returned to control values, indicating that the effect was fully reversible. It is concluded that imazalil does not induce or inhibit drug‐metabolizing enzymes in the quail, even at doses which exceed by far the maximum levels currently used to dress seed under field conditions (100 mg kg−1).
Effects of surfactants on water permeability of isolated plant cuticles and on the composition of their cuticular waxes
Authors: Riederer Markus , Schönherr Jörg 
Published: November 2006

AbstractTreating the outer surfaces of isolated cuticles of Seville orange (Citrus aurantium L.) and pear (Pyrus communis L. cv. Bartlett) leaves with a number of nonionic (polyoxyethylene) surfactants increased their permeability to water by factors ranging from 4.1 to 14.7 and from 7.2 to 152.4, respectively. However, sodium dodecylsulphate, an anionic surfactant, had little effect on water permeability. In both species the major aliphatic constituents were n‐alkanes, 1‐alkanols and n‐alkyl esters. None of the surfactant treatments altered the amounts or composition of waxes in the cuticles used for transport measurements. The reasons for the apparent absence of solubilization or dissolution of cuticular waxes by nonionic surfactants are discussed and a hypothesis is presented for the mechanism by which activator adjuvants may increase the permeability of plant cuticles.
Insecticidal activity of 3‐isoxazolyl methanesulfonates and related compounds
Authors: Jacobsen Niels , Pedersen Lars‐Erik K. , Wengel Anita 
Published: November 2006

AbstractVarious methanesulfonates, notably of 3‐isoxazolols, exhibit interesting insecticidal activity, especially against Musca domestica and Locusta migratoria. Although the symptoms of poisoning are very similar to those caused by parathion, no correlation between in‐vitro inhibition of acetylcholinesterase and insecticidal activity was observed. This is also true for several methanesulfonates of hydroxy‐heterocycles and phenols included in this study for comparison.
2‐pyrazolines with herbicidal activity
Authors: Eussen Jac H. H. , Thus Jo L. G. , Wellinga Koos , Stork Bob 
Published: November 2006

AbstractN‐(2‐pyrazolin‐1‐ylformyl)benzenesulfonamides form a new group of compounds with interesting herbicidal activity. Some of the chemical, biological and biochemical characteristics of this group are described. The herbicidal activity is mainly expressed as a post‐emergence activity on dicotyledonous weed species. The compounds appear to interfere with the biosynthesis of branched‐chain amino acids.
Inhibition of the processionary moth sex pheromone by some haloacetate analogues
Authors: Camps Francisco , Gasol Vicens , Guerrero Angel , Hernández Rodolfo , Montoya Ramón 
Published: November 2006

AbstractSeveral haloacetate analogues of (Z)‐13‐hexadecen‐ll ‐ynyl acetate, the main component of the sex pheromone of the pine processionary moth Thaumetopoea pityocampa, have been found to be good inhibitors of the natural pheromone. In field tests, the fluorinated compounds exhibited higher antipheromone activity than the corresponding chlorinated analogues, the order of activity being monofluoro > difluoro > trifluoro > monochloro > dichloro > trichloroacetate. In EAG bioassays the trifluoroacetate analogue showed the highest inhibition effect among all the compounds tested. These results agree with others previously reported, and show the primary role played by the steric size of the halogen in these analogues in order to achieve a notable inhibition of the pheromone action.
The effects of low‐volume aeration on the residues and biological effectiveness of chlorpyrifos‐methyl applied to wheat
Authors: Thomas K. P. 
Published: November 2006

AbstractThe effects of low‐volume ventilation on the persistence and biological efficacy of chlorpyrifos‐methyl applied to English wheat were investigated. Four 20‐tonne batches of wheat were treated with a dose of 2.5 mg kg−1 chlorpyrifos‐methyl. After treatment, two of the batches were aerated continuously at a rate of 17 m3 h−1 tonne−1 (10 cfm tonne−1) for 16 weeks. The remaining two batches were not aerated. Samples were collected from both aerated and non‐aerated wheat at intervals over the 16‐week storage period and subjected to biological assay using laboratory multi‐organophosphorus‐resistant strains of Tribolium castaneum, Sitophilus granarius, Sitophilus oryzae and Oryzaephilus surinamensis. The samples were also analysed for chlorpyrifos‐methyl residues. No differences in either the biological efficacy or the rate of chemical decomposition were detected between the aerated and non‐aerated wheat.
Use of crystallographic data in searching for isosteric replacements: Composite crystal‐field environments of nitro and carbonyl groups
Authors: Taylor Robin , Mullaley Anne , Mullier Graham W. 
Published: November 2006

AbstractOver 70 000 organo‐carbon crystal structures are available in the public domain. A common functional group may occur in several hundred of these structures. Examination of the immediate intermolecular environment of a functional group in each of the structures in which it occurs enables a composite crystal‐field environment to be determined. Although influenced by random packing forces, the composite environment may show strong systematic features which reflect the preferred interactions of the functional group. This is shown by test calculations on structures containing nitro and carbonyl groups, using in‐house software. Strong systematic features exist in the composite environments of both groups, showing their tendency to hydrogen bond in approximately the directions of the oxygen lone pairs, and to participate in strong electrostatic interactions in the direction normal to the plane of the group. Such results are of value in aiding the search for bioisosteres.
Imidazolinone herbicides: Synthesis and novel chemistry
Authors: Wepplo Peter 
Published: November 2006

AbstractThe imidazolinone herbicides were prepared from reaction of an α‐ methylvaline fragment with an o‐dicarboxylic acid. Early syntheses were completed through an imide amide intermediate, such as I or XV, followed by further cyclization to 2,5‐diones III or XXI. Reaction of these diones with nucleophiles led to imidazolinones IV and V. The significant and interesting activity of these compounds led to new and versatile methods of synthesis, including resolution of the α‐methylvaline fragments, development of a metallation‐carboxylation route, a one‐step picoline to imidazolinone route, and several pyridine and fused‐ring pyridine syntheses.
A field unit for determining dimethoate in fruit and vegetable dips
Authors: Noble Alan , Walsh John J. , Outhwaite Robert J. 
Published: November 2006

AbstractThe concentration of dimethoate in post‐harvest dips needs to be maintained at 400 or 500 mg litre−1 to ensure that fruit fly are killed and also to keep residue levels below the MRL. A field unit which contains a colorimeter, a heating block and cooling positions has been evaluated. The diluted dip sample produces a colour with 4‐(p‐nitrobenzyl)pyridine after heating and the addition of tetraethylenepentamine. Precision of the unit was acceptable for a field test (repeatability of ± 10.1%) and there was reasonable agreement between determinations made on the unit and by an HPLC method for a range of dimethoate concentrations from 300 to 700 mg litre−1. The unit can be used at the dip site and the analysis is completed in 30 minutes.
Inhibition of calmodulin‐dependent enzymes in rat brain by hexachlorocyclohexane
Authors: Basavarajappa B. S. , Salimath Bharathi P. 
Published: November 2006

AbstractCa2+ homeostasis is one of the major regulatory mechanisms operating in the nervous system, with calmodulin translating the Ca2+ message into cellular response. To check if hexachlorocyclohexane (HCH) acts as a calmodulin antagonist in the nervous system of rats, the in‐vitro effect of HCH on calmodulin‐dependent Ca2+‐ATPase and cAMP‐phosphodiesterase (PDE) in rat brain has been studied. In the membrane fraction from rat brain, a basal activity of Ca2+‐ATPase was obtained in the absence of Ca2+. Inclusion of Ca2+ (1 mM) increased the enzyme activity by 70%. Further, addition of fluphenazine, a potent calmodulin antagonist, inhibited the Ca2+‐dependent enzyme activity (IC50 = 85 μM), demonstrating the calmodulin dependence of the enzyme activity. The Ca2+‐ and calmodulin‐dependent Ca2+‐ATPase was inhibited by HCH in a dose‐dependent manner (IC50 = 80–90 μM). Ca2+‐ and calmodulin‐dependent cAMP‐PDE from the cytosolic fraction of rat brain was inhibited by HCH (340 μM) by 79%. Addition of excess calmodulin reversed the inhibitory effects of HCH or fluphenazine on Ca2+‐ATPase and cAMP‐PDE, suggesting their direct interaction with calmodulin. By fluorescence interaction studies it has been shown that HCH interacts directly with calmodulin. These studies show that HCH may modulate the intracellular concentration of Ca2+ and cAMP, by decreasing the effectiveness of calmodulin towards its effector enzymes, resulting in an altered signal transduction in the nervous system.
Effects of bifenox and oxadiazon on isolated chloroplasts, plant mitochondria and leaf pieces
Authors: Routaboul Jean Marc , Nurit Françoise , Ravanel Patrick , Tissut Michel 
Published: November 2006

AbstractThe effects of bifenox (methyl 5‐(2,4‐dichlorophenoxy)‐2‐nitrobenzoate) and oxadiazon (5‐tert‐butyl‐3‐(2,4‐dichloro‐5‐isopropoxyphenyl)‐1,3,4‐oxadiazol‐2(3H)‐one on photosynthetic activity were investigated in isolated chloroplasts, and on respiratory activity in isolated mitochondria. The global effects of these chemicals were also investigated on cucumber cotyledon pieces. It was found that, in vitro, bifenox and oxadiazon acted on cotyledon pieces as typical diphenyl ether herbicides, causing complete pigment bleaching, even at low concentrations. In addition, bifenox and oxadiazon were shown to inhibit the photosynthesis process at the chloroplast level. At concentrations of up to 40‐50 μM, oxadiazon and bifenox were observed to inhibit fully the light‐dependent oxygen evolution of spinach class A chloroplasts, oxadiazon acting preferentially on electron transfer at the PS II level whereas bifenox acted on the photophosphorylation process. Comparison of the amounts of herbicide needed to inhibit photosynthesis and to cause bleaching of cucumber pieces leads to the conclusion that photosynthesis inhibition by bifenox and oxadiazon is only a secondary effect.
Comparative metabolism and disposition of [14C‐benzyl] cypermethrin in quail, rat and mouse
Authors: Edwards Robert , Millburn Peter , Hutson David H. 
Published: November 2006

AbstractThe excretion and metabolism of cis + trans‐[14C‐benzyl] cypermethrin has been compared in quail, rat and mouse. Radioactivity was rapidly eliminated by quail dosed orally with [14C]cypermethrin (2 mg kg−1), as was the case in the rat and the mouse. When the birds were dosed intraperitoneally (IP) with the 14C‐labelled pyrethroid, radioactivity was excreted more slowly than after oral dosing, and almost 20% of the IP dose of 14C remained in the tissues after 7 days. Both mammalian species excreted [14C]cypermethrin more rapidly than did the avian species after IP administration, and less than 6% of the dose remained in their tissues after several days. The biotransformation of the pyrethroid was more complex in the avian species (34 metabolites) than in the two mammals (some 10 metabolites in each species). In quail the predominant reactions were ester bond cleavage of cypermethrin together with either aromatic hydroxylation or amino acid conjugation of the 3‐phenoxybenzyl moiety. The hydroxylated derivatives were eliminated mainly as sulphates. 3‐Phenoxybenzoic acid was conjugated with a variety of amino acids including glycine, taurine, glutamic acid, serine, α‐N‐acetylornithine and the dipeptide glycylualine. The last two conjugations are unique to avian species. The major metabolite of cypermethrin in the rat was the sulphate conjugate of 3‐(14‐hydroxyphenoxy)benzoic acid, whereas in the mouse the major products were 3‐phenoxybenzoic acid and its taurine conjugate. Thus, in the mammalian species where hydroxylation was maximal, amino acid conjugation was a minor metabolic route und vice versa. However, in the quail, aromatic hydroxylation and amino acid conjugation of the 3‐phenoxybenzyl moiety of cypermethrin were both major reactions. The influence of the rates and sites of metabolism, and of the enzymology of amino acid conjugation, in determining this species difference are discussed. The rapid metabolism of cypermethrin to a variety of polar conjugates that are readily excreted, together with the low brain sensitivity of birds compared with mammals to its neurotoxic effects, explains the low acute toxicity of this pyrethoid to avian species.
The phototransformation of a bis‐2,3‐diazabutadienyldisulfide to an aphicidally active 2,3‐dihydro‐1,3,4‐thiadiazole
Authors: Farooq Saleem , Steinemann Adrian , Schlaepfer Theophil 
Published: November 2006

AbstractThe pro‐insecticide bis‐(1‐(4‐chlorophenyl)‐4‐(pyrid‐3‐yl)‐2,3‐diazabutadien‐1‐yl)disulfide, I is photochemically transformed to the aphicidally active 5‐(4‐chlorophenyl)‐2‐(pyrid‐3‐yl)‐2,3‐dihydro‐1,3,4‐thiadiazole IIa.
Correlation of fluridone and dye concentrations in water following concurrent application
Authors: Fox Alison M. , Haller William T. , Shilling Donn G. 
Published: November 2006

AbstractHerbicide residue samples are expensive and time‐consuming to collect and analyze. To test whether Rhodamine WT dye could simulate the dissipation of fluridone, concurrent applications of the chemicals were made in the weed‐infested Three Sisters tidal canals (Citrus Co. Fl) and a shallow lake in the Upper St Johns River, Florida. Dye concentrations were measured using a field fluorometer and fluridone concentrations were analyzed by an HPLC method. The coefficient of correlation between dye and herbicide was 0.99 in the canals and 0.93 in Lake Hell ‘n’ Blazes (Upper St Johns River) over 340 and 93 h respectively. Half‐lives of the chemicals were not significantly different for either site. The importance of these data in relation to herbicide registration is discussed.
A scanning electron microscope study of glyphosate deposits in relation to foliar uptake
Authors: Macisaac Susan A. , Paul Rex N. , Devine Malcolm D. 
Published: November 2006

AbstractThe 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.