bluuebunny/crossref_metadata_2025_split huggingface dataset:
Azomethines of sec‐butylamine for the control of penicillium decay of oranges
Authors: Eckert Joseph W. , Rahm Michael L. 
Published: November 2006

AbstractImines, synthesised by the reaction of sec‐butylamine (SBA, 2‐amino‐butane) with pentan‐2‐one, heptan‐2‐one, octan‐2‐one, undecan‐2‐one, benzaldehyde and 2‐furaldehyde, were evaluated as vapour‐phase treatments to prevent the infection of oranges by Penicillium digitatum. All the imines provided decay control equivalent to SBA when they were introduced into the fruit container at a rate equivalent to 16.4 mg SBA litre−1 air volume. The carbonyl compound component of the imines, tested alone at a five‐fold higher rate, did not reduce fruit decay. All the imines were stable in the gaseous state in dry air. The imines of pentan‐2‐one and undecan‐2‐one were hydrolysed rapidly in a humid environment, indicating that their action against P. digitatum was due to the release of SBA into the atmosphere around the fruit. The instability of the imines of the aliphatic ketones makes them unsuitable as generators of SBA in packages. The imines derived from benzaldehyde and 2‐furaldehyde were stable in moist air, but were hydrolysed to a significant degree on moist filter paper, especially at pH < 7. These aromatic imines were absorbed from the atmosphere by the fruit and were hydrolysed rapidly in water, and in a buffer solution that represented the environment in fresh injuries on fruit. Apparently all the imines tested generated SBA in the fruit environment, and this SBA accumulated at potential infection sites, where it prevented the development of decay.
Contemplations and speculations on novel approaches in the control of fungal plant diseases
Authors: Fuchs Adriaan , Davidse Leen C. , De Waard Maarten A. , De Wit Pierre J. G. M. 
Published: November 2006

AbstractPlant disease control can, in principle, be achieved by direct and indirect methods. Novel approaches in direct plant disease control are illustrated by the group of ergosterol biosynthesis inhibitors. Consideration of their stereochemistry leads to speculations on a more rational design of chiral fungicides, with possibly optimised activity against a wider range of fungi. Studies on the mode of action of ergosterol biosynthesis inhibitors, and of the mechanism of resistance to them in fungi, suggest that these phenomena are not causally related. At least in laboratory mutants, resistance seems to be associated with altered membrane function, which may account for reduced fitness, and, in pathogens, for reduced virulence as well. The results of these studies strengthen the conclusion that knowledge of the modes of action and mechanisms of resistance, at the physiological, biochemical and molecular level, should provide a rationale on which to base the design of new systemic fungicides.As a matter of more immediate practical importance, the implications of the use of fungicide‐synergist combinations in plant disease control are briefly discussed.With respect to indirect plant disease control, novel approaches should be directed towards the activation of host resistance. However, prospects seem to be limited for the successful application of alternative chemicals that act on host resistance mechanisms by, for instance, inducing phytoalexin synthesis. Controlled activation of host resistance by localised sensitisation of resistance mechanisms may, however, become a promising new method of plant disease control in the future.
Aspects of carbon metabolism and the prospects for enhancing yields
Authors: Coombs James 
Published: November 2006

AbstractThe productivity of a given area of land depends on the amount of light falling on that area, the area of plant available to intercept the light, and a series of factors reflecting the varying efficiency of partial processes of photosynthesis. These factors include the rate of flux of carbon dioxide into the leaf, photochemical events, carbon fixation, dark respiration, photorespiration, partitioning and other metabolic events which together determine the net assimilation rate. In addition, productivity is decreased by lack of nutrient or water, disease and other stresses induced by the environment. As a result, the efficiency of trapping of solar energy into agricultural products is often less than 1% when expressed in terms of the total incident energy available. This contrasts with a theoretical efficiency of about 10% for carbon dioxide assimilated into carbohydrate, and a potential productivity of about 5% for most temperate plants. On the basis of current knowledge of carbon metabolism, the relative importance of some of the above factors in reducing the high initial rates of carbon assimilation to cause low final yields, are assessed.
A rapid high‐pressure liquid chromatographic method for the determination of carbaryl residues in wheat grain
Authors: Hargreaves Phillip A. , Melksham Kevin J. 
Published: November 2006

AbstractCarbaryl residues in wheat grain have been determined in methanol extracts using normal‐phase high‐pressure liquid chromatography (h. p. l. c.) with ultraviolet detection. A single‐injection, clean‐up and analysis technique was used to allow more rapid analysis of samples after extraction. A detection limit of 0.1 mg kg−1 in a 50 g sample of wheat was achieved. Recoveries of 86% at the 1 mg kg−1 level and 90‐99% at the 5 mg kg−1 level were obtained for fortified grain samples. Methanol was found to be a superior extractant for carbaryl from wheat when compared with hexane, acetone and dichloromethane. Twelve samples containing aged carbaryl residues were analysed by the h. p. l. c. technique and by a colorimetric procedure which allowed statistical analysis of errors. For the h. p. l. c. method (excluding sampling error), a relative standard deviation of 4.4% was obtained.
Grain protectants for the control of malathion‐resistant insects in stored sorghum
Authors: Bengston Mervyn , Cooper Lynne M. , Davies Richard A. H. , Desmarchelier James M. , Hart Richard H. , Phillips Mervyn P. 
Published: November 2006

AbstractDuplicate experiments were carried out on bulk sorghum stored in South Queensland and in Central Queensland. Bioassays of treated grain, conducted during 6 months' storage, established that fenitrothion (12 mg kg−1)+ bioresmethrin (1 mg kg−1), and pirimiphos‐methyl (4 mg kg−1)+ carbaryl (8 mg kg−1), controlled typical malathionresistant strains of Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst), and Ephestia cautella (Walker). Chlorpyrifos‐methyl (10 mg kg−1)+ pyrethrins (1.5 mg kg−1)+ piperonyl butoxide (12 mg kg−1), and fenitrothion (12 mg kg−1)+ (1R)‐phenothrin (1 mg kg−1), also controlled the strains of S. oryzae, T. castaneum and E. cautella, but were only partly effective against R. dominica. Methacrifos (15 mg kg−1) controlled all the tested species except E. cautella. Chemical assays established that the residues and rates of breakdown of these grain protectants on sorghum conformed to the general pattern for other cereal grains; residues from the above treatments were below the individual Maximum Residue Limits recommended by the Codex Alimentarius Commission.
Relationships between lipophilicity and the distribution of non‐ionised chemicals in barley shoots following uptake by the roots
Authors: Briggs Geoffrey G. , Bromilow Richard H. , Evans Avis A. , Williams Mark 
Published: November 2006

AbstractDeterminations were made of the distribution of two series of non‐ionised chemicals, O‐methylcarbamoyloximes and substituted phenylureas, in barley shoots, following uptake by the roots from solution. The concentrations in basal and central shoot sections became constant after 24 to 48 h for all but the most lipophilic chemical studied, and were then greatest for the more lipophilic chemicals. Amounts in the leaves generally increased up to 72 or 96 h, when degradation balanced translocation. The accumulation of chemical in the lower section of shoots can be ascribed to a partitioning process similar to that in roots, the chemical being partitioned between the shoot and the xylem transpiration stream; this uptake could be estimated from the octan‐1‐01/water distribution coefficients, and was predicted to be greatest for compounds for which log Kow=4. 5.
Insecticide application and degradation in sultana grapes grown for drying
Authors: McDonald Garrick , Buchanan Gregory A. , Griffiths Geoffrey R. 
Published: November 2006

AbstractFour experiments using the insecticides malathion and chlorpyrifos on mature, unharvested and harvested sultana grapes provided information on the efficiency of application and the rate of loss of insecticides, through the phases of preharvest to processing. Unharvested bunches retained 3.5‐8.1% of the active ingredient (a. i.), whereas harvested bunches laid out to dry retained 23% a. i. Insecticide decay was greatest immediately after application, probably due to volatilisation of unbound chemical, but the rate of loss was accelerated by the use of alkaline drying oils which stimulated hydrolytic degradation. Drying oils are conventionally applied to hasten drying. The residue on fruit at the end of drying was generally higher than that on the fresh fruit because of the concentration effect of dehydration. Processing and storage did not alter the residues, probably because the chemical migrated into the fruit and became bound to inert compounds.
Degradation and persistence of gamma‐HCH and chlorpyrifos‐methyl in Ponderosa pine bark
Authors: Page Marion 
Published: November 2006

AbstractResidues of gamma‐HCH and chlorpyrifos‐methyl in Ponderosa pine bark (Pinus ponderosa Laws.) were determined 7‐300 days after spray treatment, by a rapid extraction method using ethyl acetate and sodium sulphate, and analysis by gasliquid chromatography using either an electron‐capture or nitrogen‐phosphorus detector. The residue data were fitted into a power curve equation, Y = axb, to determine the rates of insecticide disappearance. The half‐life values (μg cm−2), as interpolated from the power curve, indicate that 50% disappearance occurred in 43 (± 9) days for gamma‐HCH and 102 (± 26) days for chlorpyrifos‐methyl. When half‐life values, however, are computed from extrapolated initial deposits, 50% disappearance occurred in 6 (± 1) days for gamma‐HCH and 15 (±4) days for chlorpyrifos‐methyl.
Influence of block and cell size, growing medium and insecticide dose on the behaviour and uptake of phorate by lettuce and uptake of carbofuran and chlorfenvinphos by calabrese
Authors: Suett David L. , Whitfield Christine E. 
Published: November 2006

AbstractPhorate residues in peat blocks and lettuce were determined following incorporation of the insecticide into different block and ‘Speedling’ cell sizes. Between‐block variability was influenced little by block size. Phorate oxidation was most extensive in the largest blocks containing the smallest dose. Total residue concentrations in the lettuce declined from the time of planting to harvest, although accumulation of insecticide continued and was related more to dose than to block or cell size. Residues in the lettuce at harvest exceeded the proposed maximum limit of 0.2 mg kg−1 in some treatments. Residues at planting comprised mainly the parent sulphoxide and sulphone, but by harvest, the oxygen analogue sulphoxide and sulphone predominated. Lettuce weight was not influenced by dose but was related directly to block size.Carbofuran and chlorfenvinphos residues were determined in calabrese sown into two sizes of blocks. At planting time, carbofuran residue concentrations were 100 times greater than those of chlorfenvinphos but residues of both insecticides in the mature heads were < 0.01 mg kg−1. Seedling weights in both sowings declined with increasing concentrations of the insecticides.It was concluded that manipulations of block size and the dose of insecticide need to be evaluated for individual insecticide/crop combinations to exploit the technique fully.
Phloem transport of xenobiotics in Ricinus communis var. Gibsonii
Authors: Chamberlain Keith , Burrell Michael M. , Butcher Dennis N. , White Jean C. 
Published: November 2006

AbstractWhole plants of Ricinus communis var. Gibsonii were used to study the mobility of some xenobiotics in the phloem. Solutions of 14C‐ or 35S‐labelled test compounds were introduced directly into the hollow petiole of a leaf that was exporting assimilates. Translocation was monitored by collecting phloem exudate from an incision in the stem bark beneath the treated leaf. Using [3H]sucrose as an internal standard, qualitative and quantitative results were obtained for a variety of model compounds, including herbicides, fungicides and a nematicide.
The fungicidal activity of substituted 1, 4‐naphthoquinones. Part 1: Alkylthio and arylthio derivatives
Authors: Clark Nigel G. 
Published: November 2006

AbstractSome symmetrical and unsymmetrical 2, 3‐bis(arylthio)‐1, 4‐naphthoquinones have been synthesised and assayed against Botrytis cinerea, Cladosporium fulvum and Venturia inaequalis. With the surprising exception of the 2, 3‐bis(4‐chlorophenylthio) derivative, the compounds were essentially inactive. The 2‐phenylthio and lower 2‐alkylthio derivatives showed a high level of activity, which was absent in the 2‐pentylthio and higher homologues.
Biochemical aspects of the fungitoxic and growth regulatory action of fenarimol and other pyrimidin‐5‐ylmethanols
Authors: Sisler Hugh D. , Ragsdale Nancy N. , Waterfield Willard F. 
Published: November 2006

AbstractThe C‐14 demethylation of the sterols, dependent on cytochrome P‐450, and the C‐22(23) desaturation of sterols are reactions in the ergosterol biosynthesis pathway that are regarded as primary target sites in the toxicity of fungicides of the pyrimidin‐5‐ylmethanol type. Currently, there is no evidence for target sites in other pathways of comparable sensitivity, although the failure of added ergosterol to reverse the fungitoxicity suggests the existence of such sites. The mitochondrial respiratory systems in Ustilago maydis and Aspergillus nidulans are insensitive to this type of fungicide and are not regarded as primary targets of fungitoxicity in these organisms. Appreciable evidence indicates that the primary targets in higher plant growth regulation are reactions, dependent on cytochrome P‐450, that assist in the conversion of kaurene to kaurenoic acid in the gibberellin (GA) biosynthesis pathway. Growth retardation by high concentrations of pyrimidin‐5‐ylmethanols, which is not reversable by GA, apparently involves action at sites outside the GA biosynthesis pathway. The data derived from various studies of the mechanisms of fungitoxicity and growth regulation suggest that any undetected primary targets of the pyrimidin‐5‐ylmethanols are likely to be haem enzymes, similar to the cytochrome P‐450 involved in sterol C‐14 demethylation.
Effects of fungicides on apple crown rot caused by Phytophthora cactorum
Authors: Utkhede Rajeshwar S. 
Published: November 2006

AbstractThe mycelial growth of Phytophthora cactorum on corn meal agar was completely inhibited by metalaxyl or mancozeb at 50 or 100 μg ml−1, but not by fosetyl‐aluminium at the same concentrations. Soil drenches with metalaxyl, followed by metalaxyl+mancozeb, around the base of naturally infected trees under orchard conditions, prevented the growth of P. cactorum in the infected bark of the tree. Soil drenchs with metalaxyl, followed by metalaxyl+mancozeb, also prevented the infection of apple trees with P. cactorum under orchard conditions. The trunk circumference and spur length were not significantly affected by any of the fungicide treatments in all the trials over 2 years, except in one of the four orchards used in the study. Soil drench with metalaxyl alone, or followed by metalaxyl+mancozeb, may provide an effective control method for crown rot of apple trees.
Degradation of dicarboximidic fungicides in wine
Authors: Cabras Paalo , Meloní Marco , Piri Filippo M. , Pirisi Renzo 
Published: November 2006

AbstractThe degradation of some dicarboximidic fungicides (chlozolinate, iprodione, procymidone and vinclozolin) has been studied in wine at pH values of 3.0 and 4.0, at 30°. The kinetic data obtained by observing the disappearance of the active ingredient (3.0 mg kg−1) showed the pseudo first‐order rate constants to be higher at pH 4.0 than at 3.0, with a trend for the values to be in the order: chlozolinate > vinclozolin > procymidone > iprodione. 3, 5‐Dichloroaniline was not detected as a degradation product of any of the compounds. Chlozolinate and vinclozolin in wine each yielded a major metabolite, the structures of which are proposed.
Chemical structure‐fungicidal activity relationships in substituted morpholines
Authors: Pommer Ernst‐Heinrich 
Published: November 2006

AbstractBy the N‐substitution of morpholine with alkyl or cycloalkyl groups containing 12 to 13 carbon atoms, compounds were obtained with good fungicidal activity, in particular, against powdery mildew in barley. An increase in activity was achieved when the carbon atoms in the heterocyclic ring bore one or two methyl groups, the 2,6‐combination being preferred. In the case of sterically different substances, no difference in activity was observed between the cis‐ and trans‐forms. Substituted arylalkyl amines, in which the aromatic ring and the alkylene chain were substituted appropriately, showed very good activity against powdery mildew in wheat and barley, as well as against cereal rust fungi. Steric conditions also play an important role with this type of molecule, as has been proved by detailed investigations on isomers with different configurations in the morpholine moiety, in the alkylene intermediate chain, and in the carbocycle.
A Novel 1D Coordination Polymer [Pb(phen)(μ‐N3)(μ‐NO3)]n with the First Pb2‐(μ‐N3)2 Unit (phen = 1,10‐phenanthroline)
Authors: Marandi Farzin , Mirtamizdoust Babak , Soudi Ali A. , Yilmaz Veysel T. , Kazak Canan 
Published: November 2006

AbstractA novel 1D polymeric lead(II) complex containing the first Pb2‐(μ‐N3)2 motif, [Pb(phen)(μ‐N3)(μ‐NO3)]n (phen = 1,10‐phenanthroline), has been synthesized and characterized. The single‐crystal X‐ray data showed the coordination number of Pb2+ ions to be eight (PbN4O4) with the Pb2+ ions having “stereo‐chemically active” electron lone pairs; the coordination sphere is hemidirected. The chains interact with each other via π‐π interactions to create a 3D framework.
Artificial rearing of infant rats on milk formula deficient in n‐3 essential fatty acids: A rapid method for the production of experimental n‐3 deficiency
Authors: Ward Glenn , Woods James , Reyzer Michelle , Salem Norman 
Published: November 2006

AbstractResearch into the function of docosahexaenoic acid (DHA; 22:6n‐3), the predominant polyunsaturated fatty acid (PUFA) in the central nervous system (CNS), is often hindered by the difficulty in obtaining dramatic experimental decreases in DHA in the brain and retina of laboratory rats. In this study, the artificial rearing procedure, whereby infant rats are removed from their mothers, gastrostomized, and fed synthetic formula, was used in an attempt to produce rapid changes in CNS levels of DHA. Female rats were raised, from day 4–5 of life, on one of two formulas—one containing the essential fatty acids of both the n‐6 and n‐3 series in proportions approximately equal to those of rat milk, and the other containing high levels of 18:2n‐6 but very little n‐3 fatty acid. At weaning, both groups were given AIN‐76A diets modified so that the PUFA content resembled that of the preweaning formula. At eight weeks of age, the n‐3‐deficient group exhibited decreases of more than 50% in total DHA content in the brain, accompanied by increases in arachidonic acid (AA) (20:4n‐6) and, especially, docosapentaenoic acid (22:5n‐6). Other artificially‐reared rats were mated and their offspring were also maintained on the respective diets. In spite of the fact that they had been reared artificially, the rats mated successfully and reared litters with no obvious abnormalities. At both ten days of age and again at eight weeks, offspring of the n‐3‐deficient mothers exhibited decreases of more than 90% in total DHA content. Again, the long‐chain n‐6 PUFA increased proportionately so that total PUFA levels in the brain were not lower. As these differences are greater than those commonly reported, even after 2–3 generations of normal dietary deprivation in prodents, this procedure may be an important tool in the study of the effects of n‐3 deficiency on neural development and, subsequently, of the function of DHA in nervous tissue.
Chronic administration of eicosapentaenoic acid and docosahexaenoic acid as ethyl esters reduced plasma cholesterol and changed the fatty acid composition in rat blood and organs
Authors: Frøyland Livar , Vaagenes Hege , Asiedu Daniel K. , Garras Alexis , Lie Øyvind , Berge Rolf K. 
Published: November 2006

AbstractFish oils rich in n‐3 fatty acids have been shown to decrease plasma lipid levels, but the underlying mechanism has not yet been elucidated. This investigation was performed in order to further clarify the effects of purified ethyl esters of eicosapentaenoic acid (EPA‐EE) and docosahexaenoic acid (DHA‐EE) on lipid metabolism in rats. The animals were fed EPA‐EE, DHA‐EE, palmitic acid, or corn oil (1 g/kg/d) by orogastric intubation along with a chow background diet for three months. At the end the animals were sacrificed. Plasma and liver lipids were measured, as well as lipid‐related enzyme activities and mRNA levels. The fatty acid composition of plasma and different tissues was also determined. This study shows that, compared to the corn oil control, EPA‐EE and DHA‐EE lowered plasma cholesterol level, whereas only EPA‐EE lowered the amount of plasma triacylglycerol. In liver peroxisomes, both EE preparations increased fatty acyl‐CoA oxidase FAO activities, and neither altered 3‐hydroxy‐3‐methylglutaryl (HMG)‐CoA reductase activities. In liver microsomes, EPA‐EE raised HMG‐CoA reductase and acyl‐CoAicholesterol acyltransferase activities, whereas DHA‐EE lowered the former and did not affect the latter. Neither product altered mRNA levels for HMG‐CoA reductase, low density lipoprotein‐receptor, or low density lipoprotein‐receptor related protein. EPA‐EE lowered plasma triacylglycerol, reflecting lowered very low density lipoprotein secretion, thus the cholesterol lowering effect in EPA‐EE‐treated rats may be secondary to the hypotriacylglycerolemic effect. An inhibition of HMG‐CoA reductase activity in DHA‐EE treated rats may contribute to the hypocholesterolemic effect. The present study reports that 20∶5n‐3, and not 22∶6n‐3, is the fatty acid primarily responsible for the triacylglycerol lowering effect of fish oil. Finally, 20∶5n‐3 was not converted to 22∶6n‐3, whereas retroconversion of 22∶6n‐3 to 20∶5n‐3 was observed.