bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some studies on the use of alginates for the placement and controlled release of diquat on submerged aquatic plants
Authors: Barrett Philip R. F. 
Published: November 2006

AbstractViscous solutions of sodium alginate can be extruded under water in the form of a string which will stick to weeds. The sodium alginate reacts with calcium ions to form an insoluble gel of calcium alginate so that the strings become more firmly attached to the weeds. Diquat dibromide can be incorporated into the alginate and this is slowly released into the water close to the plants. Two experiments are described in which this technique is tested in a fast‐flowing river and for localised control in a lake. Diquat dihromide was found to be effective, when formulated with alginate, on Ranunculus spp. in the river and Groenlandia densa in the lake.
Photolysis of organophosphorus insecticides on soil surfaces
Authors: Burkhard Niklaus , Guth Johann A. 
Published: November 2006

AbstractPhotolysis on soil surfaces of the organophosphorus insecticides diazinon, methidathion and profenofos was studied under artificial sunlight conditions. All three compounds were readily degraded under the conditions used. The rate of degradation decreased in the order diazinon, profenofos, methidathion and was always greater in moist than in dry soil. The same order of stability was also observed from photolysis studies in aqueous solution. The major photolysis products identified were 2‐isopropyl‐6‐methylpyrimidin‐4‐ol from diazinon, 5‐methoxy‐3H‐1,3,4‐thiadiazol‐2‐one from methidathion and 4‐bromo‐2‐chlorophenol and 4‐bromo‐2‐chlorophenyl ethyl hydrogen phosphate from profenofos. The same compounds were formed in hydrolysis studies and also upon photodecomposition in aqueous solutions of diazinon and methidathion. Profenofos, however, showed a different photolytic reaction in aqueous systems, forming O‐(2‐chlorophenyl) O‐ethyl S‐propyl phosphorothioate. Soil photolysis studies together with hydrolysis experiments could be a useful quick method for obtaining early information on the chemical breakdown products which are to be expected in the soil environment.
Kinetics of linuron and metribuzin degradation in soil
Authors: Kempson‐Jones Gillian F. , Hance Raymond J. 
Published: November 2006

AbstractThe disappearance of linuron and metribuzin was studied during laboratory incubation of soil samples which had been taken from several depths at three sites, and treated with the pesticides. Temperature and water content of the soils were varied. There was a tendency for the rate of loss to be slower in soil taken from deeper horizons than in surface soil but the differences were not large. In only ten out of forty experiments did the value 1 for the apparent order of reaction fall within 95% confidence limits. In the remaining experiments the apparent reaction order was greater than 1 with eight values higher than 4. For one soil, the reaction order for linuron was markedly lower for incubation at 22°C compared with incubations at 10°C. The results could be explained on the basis that the systems were complex, involving consecutive or competing reactions. An alternative possibility is that the apparent complexities were artifacts brought about by the inherent limitations of the laboratory incubation system.
Structure and insecticidal activities of pyrethroids available through new methods of synthesis
Authors: Greuter Hans , Bissig Peter , Martin Pierre , Flück Victor , Gsell Laurenz 
Published: November 2006

AbstractStarting from derivatives of cyclobutanone the synthesis is described of α‐cyano‐3‐phenoxybenzyl esters of 2,2‐dimethylcyclopropanecarboxylic acid, substituted in the 3‐position of the cyclopropane ring by an alkoxy, alkylthio, phenoxy or phenylthio group. The insecticidal activities of these synthetic pyrethroids towards adult Musca domestica, and larvae of Aedes aegypti, Spodoptera littoralis and Heliothis virescens are reported and compared with known pyrethroids.
The cross‐resistance to pyrethrins and eight synthetic pyrethroids, of an organophosphorus‐resistant strain of the rust‐red flour beetle Tribolium castaneum (herbst)
Authors: Lloyd C. John , Ruczkowski George E. 
Published: November 2006

AbstractComparisons with standard susceptible insects showed that a strain of Tribolium castaneum, with a specific resistance to malathion and its carboxylic ester analogues, had no cross‐resistance to topical applications of natural pyrethrins. Another strain of T. castaneum, showing resistance to many organophosphorus (OP) insecticides, was cross‐resistant to pyrethrins ( × 34) and eight synthetic pyrethroids also applied topically; least cross‐resistance occurred with resmethrin ( × 2.2), bioresmethrin ( × 3.3) and phenothrin ( × 4.0). Generally larger resistance factors were recorded with formulations synergised by piperonyl butoxide (PB). The greatest cross‐resistance encountered was with unsynergised tetramethrin ( × 338). Apart from tetramethrin, factors of synergism did not exceed 5.7 with either the susceptible or multi‐OP resistant strains. PB antagonised six of the nine pyrethroids against the multi‐OP resistant strain. Antagonism also occurred with two of these six, permethrin (cis: trans ratio 1:3) and 5‐prop‐2‐ynylfurfuryl ( 1RS)‐cis,trans‐chrysanthemate (‘Prothrin’), against the susceptible strain. Considering only formulations without the synergist, the most effective compounds against the susceptible strain, relative to pyrethrins, were bioresmethrin (2.7) and permethrin (2.4). Similarly with the multi‐OP resistant strain the most effective compounds were bioresmethrin (28), resmethrin (14) and permethrin (6.6). Thus the LD50 (the dose required to kill 50% of the test species) for bioresmethrin against the resistant strain (0.14 μg) only slightly exceeded the LD50 for pyrethrins against the susceptible strain (0.12 μg).
The herbicidal activity of 2‐alkyl‐2‐cyanoacetanilides
Authors: Geissler Arthur E. , Huppatz John L. , Phillips John N. 
Published: November 2006

AbstractThe pre‐emergent herbicidal activity of 2‐alkyl‐2‐cyanoacetanilide derivatives (a new class of anilide herbicides) is reported and the relationship between structure and activity examined. The compounds appear to act by inhibiting development of root growth. Comparisons with 2‐chloroacetanilide herbicides reveal similarities and differences which suggest that, whilst both groups may interact at a similar cellular site, a different reaction mechanism may be involved.
The effect of three fungicides, specific for the control of rice blast disease, on the growth and melanin biosynthesis by Pyricularia oryzae cav.
Authors: Woloshuk Charles P. , Wolkow Penelope M. , Sisler Hugh D. 
Published: November 2006

AbstractTricyclazole (EL 291), 4,5‐dihydro‐4‐methyltetrazolo [1,5‐a] quinazolin‐5‐one (PP 389), and pyroquilon (CGA 49104) were studied to determine the effects on growth and melanin biosynthesis by Pyricularia oryzae in vitro. The three fungicides were essentially devoid of toxicity to P. oryzae at concentrations up to 50 ug ml−1 but each selectively inhibited melanin biosynthesis at much lower concentrations. Inhibition of melanin biosynthesis resulted in the accumulation of 2‐hydroxyjuglone and flaviolin. The study indicated that the three compounds act by a similar mechanism in P. oryzae..
Spray retention and distribution on apple trees
Authors: Herrington Pamela J. , Mapother Harry R. , Stringer Austin 
Published: November 2006

AbstractTotal deposits and their distribution on bush and dwarf hedgerow apple trees, sprayed at the late dormant and full foliage stages with a copper fungicide by five different methods, were estimated by colorimetric determination of the acid‐extracted copper from all the tree parts, and for comparison purposes were converted to equivalent volumes retained. The bush trees were sprayed by hand lance (4500 litresha‐1), by automatic nozzle mast sprayer (2250 litres ha−1), by conventional air‐blast sprayer at medium volume (1125 litres ha−1) and low volume (560 litres ha−1), and by hand‐directed ultra‐low‐volume (ULVH) fan‐assisted spinning‐disc sprayer (6 litres ha−1). The hedgerow trees were sprayed by conventional air‐blast sprayer at low volume (560 litres ha−1) and by an experimental tractor‐mounted ultra‐low‐volume air‐blast sprayer (45 litres ha−1). At the late dormant stage, the bush trees retained only 9–22 % of the total spray applied by all methods, except that those sprayed by the hand‐directed ULVH sprayer retained 57%. At the full foliage stage, when most of the spray was deposited on the leaves, retention for all methods of application was 22–37%. The hedgerow trees at late dormancy retained 6% of the spray applied in low volume and 10% of that by tractor‐mounted ultra‐low‐volume methods, but at full foliage, retention was 25 and 63 %, respectively. On both types of tree the proportions of the spray deposited on the tree components were related to the surface areas of those components.
Properties of dicarboximide‐resistant strains of Botrytis cinerea
Authors: Davis Richard P. , Dennis Colin 
Published: November 2006

AbstractDicarboximide‐resistant strains of Botrytis cinerea were isolated from natural substrates and also produced in the laboratory. All these strains exhibited a similar degree of resistance to the dicarboximide fungicides iprodione and vinclozolin, and this resistance persisted in the absence of the fungicides. The natural frequency of resistance to both chemicals was approximately three in 107 conidia but could be enhanced by up to 1000 times after a single exposure to sub‐lethal concentrations of either chemical. Mycelium of the resistant strains was able to infect fruit and vegetables to a similar extent as that of sensitive strains, although infection of carrot roots was markedly less aggressive. The resistant strains were separable into two groups according to their growth habit on culture media. Both groups were relatively slow growing and showed a marked lack of sporulation compared with most sensitive strains. This lack of sporulation may account for the apparent failure of resistant strains to increase rapidly in strawberry plantations that had received dicarboximide sprays in successive seasons.
A technique for studying the biological efficiency of small droplets of pesticide solutions and a consideration of the implications
Authors: Munthali David C. , Scopes Nigel E. A. 
Published: November 2006

AbstractA simple bioassay technique is described for small, uniformly‐sized droplets of pesticide solutions obtained by use of a microtip spray nozzle. A soluble fluorescent tracer was added to the spraying solution; droplets of the solution were sprayed on leaf discs and counted under a microscope with the aid of an ultraviolet lamp. The technique was used to study the relationships between the number of drops, their size and the dicofol concentration, on the mortality of Tetranychus urticae eggs. LD50 values decreased as the drop size was reduced; the concentration of the pesticide also affected the LD50 values. The technique can be used to study the biological efficiency of ultra‐low volume pesticide formulations in the laboratory.
Effect of fungicides on the physiology of plants. Part IV: Protection of cellular organelles of senescent wheat leaves by carbendazim
Authors: Tripathi Ram K. , Tandon Komal , Schlösser Eckart , Hess Wilford M. 
Published: November 2006

AbstractWheat leaves (cv. Kormoran) floated on water and kept in darkness turned yellow. This induced senescence was accompanied by a loss of electrolytes and amino acids, and by disorganisation of all cellular organelles except cell walls. Treatment with a solution of carbendazim (20 μg ml−1) prevented the leakage of electrolytes and disorganisation of cell organelles. At 100 μg ml−1, the fungicide did not prevent the damage caused by senescence but stimulated the loss of electrolytes from the leaves. It is proposed that one of the major mechanisms of the antisenescent activity of carbendazim is its protective effect on membranes.
Measured and simulated behaviour of fluometuron, aldoxycarb and chloride ion in a fallow structured soil
Authors: Nicholls Peter H. , Bromilow Richard H. , Addiscott Thomas M. 
Published: November 2006

AbstractThe distribution with depth of fluometuron, aldoxycarb and chloride anion was measured in the field during winter in a well‐structured fallow soil. Distribution patterns measured at monthly intervals over 4 months were compared with those simulated by two different models: that of Leistra, which is representative of models using Darcy's Law to describe water movement in soil; and a modified version of that originally developed by Addiscott to describe nitrate movement, which uses the concept of mobile and immobile water categories. Both models correctly predicted the general pattern of movement but underestimated the movement of chloride ion whilst overestimating the movement of aldoxycarb and fluometuron after the first month. The model of Addiscott was encouragingly accurate in predicting the small quantities of fluometuron which penetrated to depths between 25 and 40 cm.
Distribution and likely effectiveness of spray deposits within a cotton canopy from fine ultralow‐volume spray applied by aircraft
Authors: Uk Solang , Courshee Richard J. 
Published: November 2006

AbstractIn a study to evaluate the deposit distribution from aerial sprays on cotton in the Sudan Gezira, a combination of subjective visual assessment and quantitative chemical analysis was used. Spray deposits on leaf discs, made visible in ultraviolet light by the addition of a fluorescent pigment, were subjectively grouped into classes according to a series of standards. The mean chemical deposit on the discs in each class was measured by the gas‐liquid chromatographic determination of the profenofos content. The 810 leaves needed to define the deposit distribution with good confidence could be examined economically within the required period by this combination of quick subjective assessment and subsequent quantitative chemical calibration. Results showed that the vertical profile of the deposit distribution within the canopy followed the classical exponential decay curve. The rate of decrease depended mainly on the foliage density. The foliage effectively dampened the wind turbulence so much that the penetration of visible droplets within the lower two‐thirds of the canopy was predominantly by gravity. Suggestions for the use of the deposit distribution probability to predict the likely biological effectiveness in the field are discussed.
Residues of glyphosate in irrigation water
Authors: Bowmer Kathleen H. 
Published: November 2006

AbstractIn investigations to determine the extent of contamination from typical spray applications of glyphosate, a conservative fluorescent tracer was used to predict the theoretical upper limit in channels carying flowing water. Polarographic and bioassay estimations of glyphosate showed reasonable correlation with these predictions for samples collected immediately downstream of the spray zone. The current desirable criteria of 0.1 g m−3 for drinking water in Australia, and 0.2 g m−3 approved for irrigation in the United Kingdom would be exceeded, except in sprayed channels of highest cross‐sectional area. Only about 7–17% of the glyphosate applied entered the water when a foam spray was routinely directed with a hand‐gun on to a marginal growth of Paspalum paspalodes (Michx.) Scribn., and it was calculated that this technique could reduce concentrations in the spray zone to less than 0.1 g m−3 in many situations. Tributary dilution, dispersion, and adsorption processes also attenuate the contamination downstream. The impact of dispersion processes on dissipation of the glyphosate concentration was relatively small, but the glyphosate concentration was reduced by 63% as a result of adsorption during transport downstream through 2 km of drainage channel containing deep silty sediments.
Conversion of four carbamoyloximes in soil samples from above and below the soil water table
Authors: Smelt Johan H. , Dekker Abraham , Leistra Minze , Houx Norbert W. H. 
Published: November 2006

Abstract2‐Methyl‐2‐(methylsulphinyl)propionaldehyde O‐methylcarbamoyloxime (aldicarb sulphoxide), aldoxycarb, oxamyl and methomyl were incubated at 10°C in soil samples taken from layers above and below shallow ground‐water tables at four locations in the Netherlands. Soil samples from above the water table were incubated under moist and aerobic conditions. The anaerobic conditions below the water table were simulated by incubating the soil samples under 0.5‐1 cm of ground water, and a nitrogen atmosphere. During incubation, the pH and redox potentials were measured. Less than 5% of the oxamyl and methomyl remained after one day in four water‐saturated, anaerobic subsoils. The half‐lives of aldicarb sulphoxide and aldoxycarb ranged from 5.1 to 131 days in the four anaerobic subsoils. Conversion rates in the aerobic soil layers above the water table were from 8 to more than 100 times lower than in the water‐saturated layers in the same soil profile. Half‐lives in the aerobic soils ranged from 26 days for oxamyl in loamy fine sand (pH 8.0), to 1100 days for aldoxycarb in fine sand (pH 5.0). When soil from below the water table was incubated aerobically, the conversion rates of oxamyl and aldoxycarb were drastically reduced. The opposite was found when an originally aerobic soil was incubated anaerobically. Autoclaving the incubation systems retarded the conversions.
Novel chemical approaches to crop protection: Needs and solutions
Authors: Graham‐Bryce Ian J. 
Published: November 2006

AbstractThe examination of conventional chemical methods of crop protection suggests problems and opportunities that call for alternative approaches. The need for such novel treatments is considered in relation to damaging organisms not controlled by traditional pesticides, biological availability, resistance, selectivity and compatibility with other methods within the concept of integrated pest, disease or weed management. Analysis of these needs and opportunities suggests directions in which to seek novel chemical agents including those which can attack vital processes not previously exploited as target sites, the modification of physicochemical properties determining mobility and availability, chemical formulation, symptom suppression and the manipulation of chemically‐mediated processes other than direct toxic action, and the use of agents which extend the usefulness of existing toxic agents. Examples illustrating these approaches are discussed.
Organophosphorothioates and synergised synthetic pyrethroids as grain protectants on bulk wheat
Authors: Bengston Mervyn , Davies Richard A. H. , Desmarchelier James M. , Henning Ronald , Murray William , Simpson Bruce W. , Snelson Jack T. , Sticka Rex , Wallbank Barry E. 
Published: November 2006

AbstractOrganophosphorothioates and synergised synthetic pyrethroids were used in duplicate field trials carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays using malathion‐resistant strains of insects were carried out on samples of treated grain at intervals over 9 months. These established that all treatments were generally effective. Deltamethrin (2 mg kg−1)+ piperonyl butoxide (8 mg kg−1), fenitrothion (12 mg kg−1)+ fenvalerate (1 mg kg−1)+ piperonyl butoxide (8 mg kg−1), fenitrothion (12 mg kg−1)+ phenothrin (2 mg kg−1)+ piperonyl butoxide (8 mg kg−1) and pirimiphos‐methyl (4 mg kg−1)+ permethrin (1 mg kg−1)+ piperonyl butoxide (8 mg kg−1) controlled common field strains of Sitophilus oryzae (L.) and Rhyzopertha dominica (F.). Against a highly resistant strain of S. oryzae, deltamethrin (2 mg kg−1)+ piperonyl butoxide (8 mg kg−1) was superior to the remaining treatments. All treatment combinations completely prevented progeny production in Tribolium castaneum (Herbst), T. confusum Jacquelin du Val and in Ephestia cautella (Walker).Residues of deltamethrin, fenvalerate, permethrin and phenothrin were determined and shown to be highly persistent on stored wheat. During milling, residues accumulated in the bran fractions and were reduced in white flour. They were not significantly reduced during baking.
The distribution of aldicarb and its metabolites between Lumbricus terrestris, water and soil
Authors: Briggs Geoffrey G. , Lord Kenneth A. 
Published: November 2006

AbstractAldicarb is taken up by earthworms from aqueous solution to give concentrations in the worms comparable to that in the external aqueous solutions. Uptake from waterlogged soils is similar, but much less aldicarb is taken up from drier soils. Aldicarb sulphoxide [2‐methyl‐2‐(methylsulphinylpropionaldehyde O‐methylcar‐bamoyloxime], aldoxycarb and oxamyl are poorly taken up, giving concentrations in the worm of about 5% of the external aqueous concentration. In worms, aldicarb is rapidly converted to the sulphoxide which has a half‐life in worms of 19 h at 15°C, and 50 h at 5°C.
Effect of spraying techniques on the brown rot of peach fruit, and on black spot, powdery mildew and the two‐spotted mite of apple trees
Authors: Whan James H. , Smith Ian R. , Morgan Norman G. 
Published: November 2006

AbstractApplication by hand‐held equipment of the commercially recommended doses of proprietary formulations of captan (9.0 g a. i. per tree), mancozeb (10.8 g a. i. per tree), oxythioquinox (1.1 g a. i. per tree), and cyhexatin (1.8 g a. i. per tree), in spray volumes ranging from 0.225 to 9.0 litres per tree, gave commercial control of the brown rot of peach fruit, and of black spot (apple scab), powdery mildew and the two‐spotted mite (Tetranychus urticae) of apple trees. Commercial control was also obtained using a quarter of the recommended doses when applied in 0.225 or 2.25 litres per tree.The residue of oxythioquinox on the leaves, immediately after applying 1.1 g a. i. per tree, doubled as the volume of spray was reduced from 9.0 to 2.25 litres per tree, and increased further when the volume was reduced to 0.225 litres per tree. It is suggested that some of the oxythioquinox ran off the trees at the higher volumes, and that less run‐off at lower volumes resulted in higher chemical residues.
Resistance to fungicides which inhibit ergosterol biosynthesis in laboratory strains of Botrytis cinerea and Ustilago maydis
Authors: Leroux Pierre , Gredt Michel 
Published: November 2006

AbstractThe strains of Botrytis cinerea or Ustilago maydis selected on fenarimol, triarimol, or triadimefon were also resistant to the other inhibitors of sterol C‐14 demethylation; the sterol composition of the strains was normal. Among the isolates of U. maydis resistant to dodemorph, fenpropidin, fenpropimorph and tridemorph, some were resistant to the 15‐azasteroid A 25822B and did not contain ergosterol. The other strains remained sensitive to A 25822B and had a normal sterol composition. All the resistant isolates and the wild‐type were inhibited to the same extent by nystatin and pimaricin.