bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photodynamic herbicides VIII. Mandatory requirement of light for the induction of protoporphyrin IX accumulation in acifluorfen‐treated cucumber
Authors: Nandihalli Ujjanagouda B. , Liebl Rex A. , Rebeiz Constantin A. 
Published: November 2006

AbstractIt is shown that continuous illumination is mandatory for the induction of tetrapyrrole accumulation in acifluorfen‐sodium‐treated plants and for the photosensitization of tetrapyrrole‐dependent photodynamic damage. At low concentrations of acifluorfen‐sodium (up to 20 μM), photoporphyrin IX appears to be the major light‐induced tetrapyrrole that accumulates in the treated plants. At higher concentrations of acifluorfen‐sodium, monovinyl chlorophyllide a accumulates in addition to protoporphyrin IX. In the light, the development of photodynamic injury appears to be directly related to the accumulation of the light‐induced tetrapyrroles. For example when acifluorfen‐sodium‐treated plants are returned to darkness, or are treated with tetrapyrrole biosynthesis inhibitors, tetrapyrrole accumulation and photodynamic injury come to a halt. In‐vivo and in‐organello studies failed, however, to support the commonly held hypothesis that the induction of tetrapyrrole accumulation in the light, in acifluorfen‐sodium‐treated plants, is only dependent on the inhibition of protoporphyrinogen oxidase. Indeed, when plastids capable of very high rates of tetrapyrrole biosynthesis and accumulation were incubated with δ‐aminolevulinic acid and acifluorfen‐sodium, either in darkness or in the light, a severe inhibition of protoporphyrin IX and total terapyrrole formation was observed. Althoung these results are compatible with the inhibition of tetrapyrrole formation by acifluorfensodium at the level of protoporphyrinogen oxidase, they indicate that, in addition to that inhibition, other cuellular processes are probably involved in the light‐dependent accumulation of protoporphyrin IX in acifluorfensodium‐treated plants.
Evaluation of dicarboximide residues in cold‐stored grapes exposed to field and post‐harvest treatments
Authors: Scrano Laura , Faretra Franco , Cariddi Corrado , Antonacci Emmanuele , Bufo Sabino A. 
Published: November 2006

AbstractDicarboximide fungicides were used in field treatments as well as in post‐harvest fumigations on cold‐stored table grapes. They proved to be highly effective against gray mould, a major disease during storage or transport of grapes, and a valuable alternative to sulphur dioxide within one month after harvesting.Residues of the fungicides were determined through gas‐chromatographic analysis on grapes field‐sprayed with dichlozolinate, iprodione, procymidone or vinclozolin, and on grapes exposed to post‐harvest treatments with new smoke formulations of procymidone and vinclozolin. In most cases, residue levels were lower than those allowed by Italian sanitary laws. Post‐harvest fumigations caused only a slight increase of residue levels as compared to field applications.
Deamination of metribuzin in tolerant and susceptible soybean (Glycine max) cultivars
Authors: Fedtke Carl 
Published: November 2006

AbstractThe deamination of metribuzin was studied in vitro in peroxisomes isolated from the leaves of soybean cultivars which were either metribuzin tolerant, intermediate, or sensitive. The deamination rate observed with peroxisomes from tolerant leaves was about twice the rate observed with peroxisomes from sensitive leaves. The intermediate group was also intermediate with respect to the in‐vitro deamination rate.Tolerant and sensitive intact soybean plants were pulse‐labeled with [14C]metribuzin via the roots for 5 h. The extractable radioactivity in roots, stems and leaves was measured and separated into metabolites after the 5 h pulse and after an additional 24 h growth in water. The level of DA (deaminated metribuzin) was always significantly higher in the stems and leaves of tolerant soybean plants (4.8–10.0% of the extracted radioactivity) than in sensitive stems and leaves (1.8–2.9%). Conjugates were rapidly formed in tolerant as well as in sensitive soybean tissues. More conjugates were found in the tolerant cultivars, especially after the 5 + 24 h incubation time.Labeled [14C]DA fed to soybean plants via the roots was conjugated two to four times faster than [14C]metribuzin. Tolerant soybean tissue conjugated [14C] DA two to three times faster than sensitive tissue. The results are interpreted as showing that, in tolerant soybean plants, metribuzin is metabolized via deamination and subsequent conjugation, in addition to the well‐known direct conjugation of metribuzin parent compound.
Distribution and metabolism of abamectin in larval stages of Spodoptera littoralis boisduval and Heliothis armigera hübner (Lepidoptera: Noctuidae)
Authors: Christie Paul T. , Wright Denis J. 
Published: November 2006

AbstractComparisons were made between the amounts of abamectin and total radioactivity recovered from Spodoptera littoralis and Heliothis armigera larvae after topical application of [3H]abamectin. Penetration (as shown by wash‐off experiments) did not differ significantly between the Spodoptera instars. Significantly more abamectin was recovered from ventral nerve cord samples of larvae showing symptoms of poisoning than from larvae not showing these symptoms. Fifth‐instar S. littoralis larvae had a significantly lower proportion of radioactivity as abamectin in the ventral nerve cord than in sixth‐instar S. littoralis or fifth‐ and sixth‐instar H. armigera. The proportion of radioactivity present as abamectin (but not total radioactivity) was significantly increased when the fifth‐instar S. littoralis larvae were pre‐treated with piperonyl butoxide (PB) suggesting that the relative insensitivity of fifth‐instar S. littoralis larvae to abamectin is due at least in part to greater metabolism, particularly by microsomal oxidases. Fat body samples consistently had a greater proportion of radioactivity as abamectin than the nerve cord and the former may act as storage sites for abamectin.
Mode of action of herbicidal ALS‐inhibitors on acetolactate synthase from green plant cell cultures, yeast, and Escherichia coli
Authors: Babczinski Peter , Zelinski Thomas 
Published: November 2006

AbstractInhibitors of branched‐chain amino acid biosynthesis—by inhibiting acetolactate synthase (ALS)—represent the most active group of herbicidal compounds to date (Shaner, D.L., Recent Adv. Phytochem. 23 (1989) 227–61). A microbial screening technique has been developed to investigate known and possible new ALS‐inhibitors. Escherichia coli mutant FD 1062, which expresses only valine‐resistant ALS II isoenzyme as the solely branched‐chain amino acid synthesizing isoenzyme, has been used extensively to optimize known and to screen for new chemical classes of ALS‐inhibitors, respectively. Herbicidal compounds like sulfonylureas, triazolopyrimidines, pyrimidylsalicylates, carbamoylpyrazolines, sulfonylimino‐azinyl‐heteroazoles, sulfonylamide azines, and substituted sulfonyldiamides, respectively, are active on minimal medium with Ki‐values which resemble the rank order of biological activity of these compounds in the greenhouse. Interestingly, herbicidal imidazolinones are not at all inhibitory on E.coli strain FD 1062 in vivo although, of course, they exert high activity on isolated bacterial ALS. Similarly, N‐protected valylanilides, pyrimidyl mandelic acids, benzenesulfonyl carboxamides, and uhiquinone‐O are inactive in the bacterial assay but have been shown by other methods to act as ALS inhibitors. Additionally, reversal experiments can he performed to exclude, e.g. artificial inhibitory effects of test compounds. Moreover, a thin‐layer biogram application technique opens the opportunity to test mixtures of chemicals.From green plant cell cultures (Catharanthus roseus) ALS has been isolated and characterized in terms of inhibition by sulfonylureas, imidazolonones, triazolopyrmidines, salicylated, and carbamoylpyrazolines, imidazolinones, triaiolopyritnidines, salicjdates, and carbarnoylpj˜razolines,
respectively. All five types show biphasic slow tight binding kinetics with
Stedy state I50values of 0.5 nm (sulforneturon), 1.9 nm (triazolopjirimidine),
8.3 nm (salicylate), 23 nm (imazapyr), and 135 nm (carbamoylpyrazoline),respectiuely .Isolated ALS from Saccharomyces cerevisiae is equallv well blocked by
herbicidal ALS inhibitors although with different I50values ( triazoiopyrimidine, 21 nm, sulforneturon, 70 nm, salicylate, 21 μm, imaiapyr, 38μm, and carbamoylpyrazoline, 148 μm ). Surprisingly, biphasic kinetics could not be observed with the yeast enzjtme although slow binding hehauiour was clearly established.
Exprimental assessment of pesticide leaching using undisturbed lysimeters
Authors: Kördel Werner , Herrchen Monika , Klein Werner 
Published: November 2006

AbstractOutdoor lysimeter experiments are integrated studies, which consider the comprehensive influence of environmental variables on the mobility and fate in soil of a chemical and its plant uptake, and give valid information on its potential for groundwater contamination. The interpretation of the studies has to consider:

that migration behaviour under environmental conditions does not correspond with ‘ideal chromatographic behaviour’ and
that lysimeter studies include the variables of field experiments and are not fully standardized. The results of lysimeter studies on chloethocarb and bentazone are discussed.
The chemistry and biological activity of a new class of azole fungicides: 1‐amino‐1,2,4‐triazoles
Authors: Basarab Gregory S. , Pifferitti Michael , Bolinski Martha M. 
Published: November 2006

AbstractThe fungicidal activity of a novel class of triazole compounds in which the 1‐position of the azole nucleus is bonded to a nitrogen atom was investigated. Such 1‐amino‐1,2,4‐triazoles are amenable to great structural variation which allows the elucidation of the requirements for biological activity. As in most other triazole fungicides, the basic structural requirement for activity is a two‐atom bridge connecting the azole nucleus to a hydrophobic group, typically an aromatic ring. The synthesis and optimization of fungicidal activity of this class of triazole fungicide are discussed.
Synthesis of 1,2,4‐triazole compounds related to the fungicides flutriafol and hexaconazole
Authors: Worthington Paul A. 
Published: November 2006

AbstractTriazole and imidazole compounds are important both as pharmaceutical and agrochemical fungicides. It has been demonstrated that they exhibit this activity because they inhibit the 14 α‐demethylase enzyme involved in the biosynthesis of fungal sterols. A knowledge of the mode of action of the triazoles paclobutrazol, diclobutrazol and propiconazole has made it possible to devise inhibitors of the 14 α‐demethylase enzyme somewhat more readily, using computer graphic techniques. These techniques were used in the discovery of flutriafol, one of the first examples of a triazole tertiary alcohol structure. They also assisted in identifying other triazole tertiary alcohol structures for testing as fungicides. Hexaconazole is one example of a highly active broad‐spectrum fungicide. Modification of the hexaconazole structure has produced many other active fungicides, many of which can be conveniently synthesised by the addition of organometallic (e.g. lithium, magnesium, aluminium, titanium or zinc) reagents to α‐1,2,4‐triazol‐1‐yl ketones or α‐haloketones. Alternatively, they can be prepared by the reaction of nucleophiles such as mercaptans, nitrogen heterocycles or organometallic (e.g. magnesium) reagents with epoxides.
Chemistry and biology of novel amine fungicides: Attempts to improve the antifungal activity of fenpropimorph
Authors: Akers Alan , Ammermann Eberhard , Buschmann Ernst , Götz Norbert , Himmele Walter , Lorenz Gisela , Pommer Ernst‐Heinrich , Rentzea Costin , Röhl Franz , Siegel Hardo , Zipperer Bernhard , Sauter Hubert , Zipplies Matthias 
Published: November 2006

AbstractIn spite of considerable efforts by many workers, there has been a lack of progress in the area of amine fungicides since fenpropimorph. Random synthesis of a large variety of different amine compounds, as well as intelligent structural modification of the lead structure fenpropimorph (well over 15 000 amines have been screened at BASF alone) have not led to a new market product so far. Further work has been focused on the reported mode of action of fenpropimorph, notably on the inhibition of the sterol Δ14‐reductase. Although some doubt has to be cast on the hypothesis that fenpropimorph behaves as a sterol mimic, the concept of ‘high energy intermediate’ inhibitors has been employed successfully. Rational drug design of azasterol mimics has led to a number of very potent inhibitors of the sterol Δ14‐reductase which also displayed high fungicidal activity in the greenhouse. Although many of these compounds are more powerful reductase inhibitors than fenpropimorph, under field conditions none showed significant advantages over this established fungicide.Most likely, fenpropimorph already exhibits the maximum fungicidal activity which can be attained by blocking the sterol Δ14‐reductase. This would mean that, with the development of the ‘second generation’ amine fungicide fenpropimorph, this class of compounds has already virtually been optimized.
Synthesis of a new class of pyridine herbicide
Authors: Lee Len F. , Stikes Gina L. , Sing Larry Y. L. , Miller Maria L. , Dolson Mark G. , Normansell Jean E. , Auinbauh Susan M. 
Published: November 2006

AbstractA new class of fluoroalkylated pyridine herbicides has been discovered. The 3,5‐pyridinedicarboxylates are prepared either from ethyl 4,4,4‐trifluoroacetoacetate via Hantzsch dihydropyridine synthesis or from trifluoroacetonitrile via cyclocondensation and carboxylation. Hydrolysis of the ester groups, followed by derivatization of the resulting acids yields a variety of herbicidally active analogs including ester, thioester, amide, halogen, amino, alkoxy and alkylthio derivatives.
Photolysis of acifluorfen in aqueous solution
Authors: Pusino Alba , Gessa Carlo 
Published: November 2006

AbstractThe photolysis of acifluorfen, sodium 5‐[2‐chloro‐4‐(trifluoromethyl)‐phenoxy]‐2‐nitrobenzoate (I) in aqueous solution afforded only 2‐chloro‐1‐(4‐nitrophenoxy)‐4‐trifluoromethylbenzene (II) arising from photodecarboxylation. The reaction followed first‐order kinetics, though the photo‐reaction rate was solvent‐dependent. A mechanism that accounts for the formation of the product is proposed.
Insecticide resistance in the bollworm, Helicoverpa armigera from Indonesia
Authors: McCaffery Alan R. , Walker Andrew J. , Topper Clive P. 
Published: November 2006

AbstractHelicoverpa armigera collected from cotton growing areas of South Sulawesi, Indonesia in 1987 and early 1988 were resistant to cypermethrin. It is suggested that the 86‐fold resistance to cis‐cypermethrin in 1987 and the 65‐fold resistance to cis/trans‐cypermethrin in 1988 are consistent with this being a major cause of failure to control the insects in cotton in this area. The second laboratory generation showed a 20‐fold resistance to fenvalerate. The larvae collected in 1988 additionally had a 203‐fold resistance to DDT and a 5.6‐fold resistance to endosulfan. The results are discussed in relation to the fact that this is a further region in which Helicoverpa armigera has developed resistance to a number of pyrethroids.
A barn owl feeding study with [14c]flocoumafen‐dosed mice: Validation of a non‐invasive method of monitoring exposure of barn owls to anticoagulant rodenticides in their prey
Authors: Eadsforth Charles V. , Dutton Alan J. , Harrison Elizabeth G. , Vaughan John A. 
Published: November 2006

AbstractA study was carried out to assess the feasibility of monitoring the exposure of barn owls (Tyto alba) to an anticoagulant rodenticide, flocoumafen, by analysis of residues in regurgitated pellets following consumption of flocoumafen‐contaminated mice. Mice were fed on a diet containing [14C]flocoumafen, equivalent to 12 mg kg−1, and killed 24 h later. A single [14C]flocoumafen‐contaminated mouse was fed to each of four captive barn owls, equivalent to 0·11‐0·23 mg kg−1 per bird, followed on seven successive days by control diet (i.e. undosed mice). The [14C]flocoumafen dose was eliminated by the owls over the eight‐day period in pellets (44%, range 35–55%) and faeces (18%, range 11–21%), with the highest residues being observed in samples from the first 24‐h period. Further detailed analysis of the pellets confirmed that flocoumafen residues in the first‐day pellets represented 15% (range 8–26%) of the original flocoumafen residues ingested by the barn owls. Calculations based on these data and typical flocoumafen residues in live captured rodents (following baiting) confirm that pellet residue analysis is a sensitive and appropriate method for the non‐invasive monitoring of exposure of barn owls to flocoumafen. There were no symptoms of anticoagulant poisoning in any of the birds; two of the birds were successfully paired the next season and produced fledgelings.
Organophosphorus insecticide residues in virgin Greek olive oil, 1988–1990
Authors: Lentza‐Rizos Chaido , Avramides Elizabeth J. 
Published: November 2006

AbstractOrganophosphorus insecticide residues have been monitored for two years in virgin olive oil after dimethoate and fenthion treatments to control the olive fruit fly. No dimethoate residues were detected in any of the samples. For the first and second years, 50% and 21%, respectively, of the samples contained no detectable fenthion residues, while 4% and 6%, respectively had residue concentrations exceeding the Codex Alimentarious Maximum Residue Limit (1 mg kg−1). The mean concentration was 0·236 mg kg−1 oil and the estimated daily intake of fenthion 0·0002 mg kg−1 body weight (Acceptable Daily Intake 0·001 mg kg−1 body weight). The parent compound was the most important residue in fresh samples, while aged samples contained a higher amount of the metabolite fenthion sulfoxide. The contribution of the oxygen analogues (P= 0 metabolites) of fenthion to the total residue concentration was<5% in most cases.
Resistance risk assessment of two insect development inhibitors, diflubenzuron and cyromazine, for control of the housefly Musca domestica. part i: Larvicidal tests with insecticide‐resistant laboratory and danish field populations
Authors: Keiding Johannes , Jespersen Jørgen B. , El‐Khodary Ahmed S. 
Published: November 2006

AbstractLarvicide tests with diflubenzuron (DFB) and cyromazine (CYR) were carried out against 15 laboratory housefly strains and 89 field strains collected from 87 Danish and 2 Swedish farms, 1975–89. The strains represented a wide range of adult insecticide resistance and R‐mechanisms.The larvicide tests were done by treating larval medium with serial or discriminating dosages of the larvicide, seeding it with eggs and calculating the mortality during development to adults. The WHO susceptible strain (S) was used as a reference.Dose‐response tests with DFB gave resistance ratios (R/S) from 1·1 to 4·1 at LC50 and 0·3 to 3·4 at LC95 and, with CYR, R/S from 0·6 to 1·8 at LC50 and 0·6 to 2·9 at LC95.It was concluded that the relatively small variation in susceptibility between strains was not generally correlated with resistance in adult flies to organophosphorus, pyrethroid or other conventional insecticides (neurotoxins).Tests with discriminating dosages of DFB (59 farms) and CYR (63 farms) showed no indication of resistance to either product.The results of investigations by other workers on the relation between resistance to DFB or CYR and resistance to conventional insecticides are discussed.
Factors affecting the performance and crop phytotoxicity of a new rice herbicide, cinmethylin. I. Effects of water depth and soil type on the distribution and uptake of cinmethylin by transplanted and direct‐seeded rice
Authors: Terence Grayson B. , Webb James D. 
Published: November 2006

AbstractFollowing successful glasshouse evaluation, first‐year field trials showed that cinmethylin could give excellent control of barnyard grass (Echinochloa crus‐galli) in rice paddies. However, for the successful development of a herbicide in rice, a thorough understanding of its distribution over time between water, soil and plants as affected by water depth and soil type is necessary.An application of an emulsifiable concentrate formulation to laboratory paddies containing transplanted rice showed that more of the cinmethylin became associated with and moved into the soil of shallow paddies than in the more usual deep paddies. After the first day this resulted in slightly higher concentrations of cinmethylin being accumulated by the apical meristem, the site of action of cinmethylin, in shallow‐paddy plants and explains the higher phytotoxicities observed in this situation. Rapid removal of cinmethylin by the soil from the paddy water could reduce that available for absorption by the apical meristem of barnyard grass, just below the water surface, and might result in poorer control of this weed. Deeper paddies are therefore recommended for the use of cinmethylin in transplanted rice.An experiment involving direct‐seeded rice confirmed that a decrease in paddy water depth and higher organic‐matter soils increased the association of cinmethylin with the paddy soil. Thus paddy‐water concentrations and availabilities of cinmethylin to various parts of plants were influenced by water depth and soil type. In contrast to transplanted rice, the apical meristem of direct‐seeded rice is submerged in the paddy water and the stem concentrations of cinmethylin were then generally correlated with the paddy‐water concentrations. They were highest from the shallow, sandy paddies and lowest from the deep, silt clay loam paddies. These relative concentrations correlate with observed relative phytotoxicities of direct‐seeded rice, activities against barnyard grass and the narrower selectivity margins between the weeds and the direct‐seeded crop.The cinmethylin concentrations in the apical meristems of the transplanted rice were always lower than those from the direct‐seeded rice and give an illustration of a classical case of depth protection' of a crop from an applied herbicide.
Study on rare‐earth complexes of mixed amino‐acids (MAR) in controlling disease and stimulating growth of wheat
Authors: Li Zhichang , Liu Chiqing , Xu Younglin , Liu Dengmin 
Published: November 2006

AbstractMAR is a rare‐earth complex of mixed amino‐acids which was recently synthesized in the similar way to homodemycine. Five‐year field trials have proved that MAR not only stimulates crop growth and increases crop yield but also effectively controls stripe rust of wheat, and upgrades the quality of crops. This paper describes the results of the application of MAR in controlling disease and stimulating growth of wheat.
Evaluation of permethrin for the protection of cattle against mosquitoes (diptera: Culicidae), applied as electrostatic and low pressure sprays
Authors: Shemanchuk Joseph A. , Spooner Roy W. , Golsteyn Lorraine R. 
Published: November 2006

AbstractPermethrin was tested for the protection of cattle against field populations of mosquitoes. Permethrin (500 ml of a permethrin 4·0 g liter−1 aqueous emulsion) applied with a ‘Dual‐Cloud’ electrostatic sprayer was effective in providing coverage of the cattle body surface of a group of four animals; 100 ml of a permethrin 5·0 g liter−1 aqueous emulsion applied with a ‘Dual‐Cloud'’ electrostatic sprayer as a total body spray to a yearling heifer provided 70% or better protection from field populations of mosquitoes for at least 72 h; 500 ml of a permethrin 1·0 g liter−1 aqueous emulsion applied as a low‐pressure spray to the body of a yearling heifer provided 70% or better protection from mosquitoes for at least 140 h. Permethrin applied as a total body‐spray thus provides adequate protection to cattle from field populations of mosquitoes.