bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of pyromorphite in mine‐waste contaminated soils by ATEM and EXAFS
Authors: COTTER‐HOWELLS J.D. , CHAMPNESS P.E. , CHARNOCKY J.M. , PATTRICK R.A.D. 
Published: July 2006

SummaryCalcium‐rich pyromorphite [Pb5(PO4)3Cl] has been positively identified as the major lead‐bearing phase in mine‐waste soils from the South Pennine Orefield, UK, by a combination of EXAFS spectroscopy, ATEM and XRD. Evidence for a pyromorphite‐like structure was provided by electron diffraction of individual Ca‐rich, lead chlorophosphate grains in the soil using ATEM. Approximate unit‐cell parameters derived from electron diffraction were used to identify peaks on the powder XRD trace obtained from the soil sample, allowing the cell parameters to be refined. The unit‐cell parameters derived for the Ca‐rich pyromorphite [a= 0.9789(7), c= 0.726(1) nm] are smaller than those reported for pure end‐member pyromorphite (a= 0.998, c= 0.733 nm; Baker, 1966) and are sufficiently different to prevent positive identification by conventional XRD analysis. Lead absorption spectra and interatomic distances obtained from EXAFS performed on bulk soils confirmed the predominance of pyromorphite‐like structure. EXAFS is shown to be a useful tool in the identification of soil minerals. It gives information about the local environment of one specific element in solids, be they crystalline or amorphous, and is unaffected by the limited chemical substitution of Ca for Pb.The identification of impure Pb minerals in soil by techniques other than XRD suggests that previous studies, based on XRD, may have underestimated the amount of soil Pb present as discrete Pb compounds.
Characterization of phosphate species in urban sewage sludges by high‐resolution solid‐state 31P NMR
Authors: FROSSARD E. , TEKELY P. , GRIMAL J.Y. 
Published: July 2006

SummaryThe mineral forms of phosphorus in three urban sewage sludges were characterized using high‐resolution solid‐state phosphorus‐31 nuclear magnetic resonance (NMR) coupled to a sequential extraction. The sludges studied were an anaerobically‐digested and heat‐treated sludge (Paris‐Achères), an activated sludge (Briare) and an anaerobically‐digested sludge (Nancy). NMR observations were conducted using both single‐pulse and cross‐polarization sequences in order to distinguish between 31P nuclei far from 1H nuclei, and 31P located within a fraction of a nanometre of 1H. This approach showed that a complex mixture of P species was present in these sludges. A mixture of hydrogenated octocalcium phosphates and apatites was observed in the three samples. Monetite was present in the anaerobically‐digested sludge and brushite in the activated sludge. Dehydrogenated condensed calcium phosphates (compounds with a Ca:P ratio higher than 1.0 such as fluorapatite or tricalcium phosphate) and dehydrogenated pyrophosphates were also probably present in the anaerobically‐digested sludge. A poorly‐ordered wavellite was observed in the three sludges after the HCl extraction. However, results were inconclusive as to whether this mineral was present in the three sludges, or had been precipitated during the sequential extraction.
A REVIEW OF EXPERIMENTAL WORK WITH DIQUAT AND RELATED COMPOUNDS
Authors: CRONSHEY J. F. H. 
Published: July 2006

Summary. Published literature on diquat (9,10‐dihydro‐8a, 10a‐diazonia phenanthrene dibromide; 1,1′‐ethylene‐2,2′‐dipyridylium dibromide) and related dipyridyl herbicides is reviewed. Their activity is probably connected with the formation of stable free radicals on reduction and both photosynthetic and respiratory processes may be associated with free radical formation in the plants. These herbicides are rapid‐acting translocated desiccants and kill the aerial parts of most plants, but are safe as soon as they touch the ground, having no residual effect through the soil. Possible uses are as desiccants, in place of cultivation to clear fallows and seedbeds before sowing, in pre‐emergence weedkilling, for weeding round trees and bushes and, with directed spraying, for inter‐row weeding in row crops.Revue des essais effectués avec le Diquat et des composés apparentés
UNTERSUCHUNGEN ÜBER DAS VERHALTEN VON SIMAZIN IM BODEN
Authors: BURSCHEL P. 
Published: July 2006

Zusammenfassung. Zur Untersuchung des Abbaus von Simazin im Boden wurden Versuche angestellt. Die quantitative Bestimmung des Herbizids geschah nach der Methode von Delley (1958). Es können folgende Feststellungen gemachten werden: (1) Der Abbau von Simazin im Boden erfolgt als Reaktion I. Ordnung. Das bedeutet, dass — unter sonst gleichen Bedingungen — zu einem gegebenen Zeitpunkt der gleiche Prozentsatz der Ausgangsdosierung im Boden nachweisbar ist, unabhängig davon, wie hoch diese gewählt worden war. (2) Der Abbau ist in starkem Masse temperaturabhängig. Eine Verringerung der Temperatur von 25°C auf 8,5°C verlangsamte die Abbaugeschwindigkeit um das 7fache. (3) Der Abbau von Simazin im Boden ist vom Vorhandensein von Humussubstanz abhängig. Fehlt sie, findet kein Abbau statt; mit zunehmendem Anteil wird der Abbau beschleunigt. Daraus wird der Schluss gezogen, dass die Vorgänge durch Mikroorganismen bewirkt werden. (4) In schweren Böden bleibt Simazin auch nach erheblichen Niederschlägen in den oberen 0–4 cm des Bodens. Mit zunehmendem Sandanteil steigt die Wahrscheinlichkeit, dass geringe Mengen des Mittels auch in tiefere Schichten eindringen. (5) Die Beobachtung des Abbaus von zwei Dosierungen des Präparates unter Feldbedingungen bestätigte die Ergebnisse der Laborversuche.Experiments on the breakdown of simazine in the soil
MOVEMENT OF 2,6‐DICHLOROBENZONITRILE IN SOILS AND IN PLANTS IN RELATION TO ITS PHYSICAL PROPERTIES
Authors: MASSINI P. 
Published: July 2006

Summary. The movement of the herbicide H133 (2,6‐dichlorobenzonitrile) in soils and in plants is shown to be governed mainly by its relatively high volatility, its low solubility in water and its strong adsorption on lignin, on humic matter and on lipid material. Some evidence for a transformation of H133 in plants is presented.Les déplacemcnts du 2,6‐dichlorobenzonitrile dans les sols et dans les plantes et leurs relations avec les proriétés physiques
THE FATE OF N'‐(4‐CHLOROPHENOXY)‐PHENYL‐NN‐ DIMETHYLUREA (C‐1983) IN SOILS AND PLANTS*
Authors: GEISSBÜHLER H. , HASELBACH C. , AEBI H. , EBNER L. 
Published: July 2006

Summary. Seedlings of Galinsoga parviflora and Polygonum convolvulus were cultured in nutrient solution and soil with C‐1983‐14C. Uptake and translocation of herbicide was followed by measuring radioactivity in roots, stems and leaves as a function of time. The capacity of the two plants to take up C‐1983 from nutrient solution and to translocate it into stems and leaves was found to be strikingly different. The difference in herbicidal effect of C‐1983 on the two species parallels the concentration of radioactivity translocated into leaves. Uptake of C‐1983 from nutrient solution as well as subsequent translocation to top parts by lowering temperature increasing humidity and transfering the plants from light to darkness.In soil cultures, the two plants were found to take up and to translocate smaller quantities of C‐1983 than was to be expected from the calculated soil solution concentration.The mechanisms regulating the rate of uptake C‐1983 from nutrient cultures and soils are discussed. The strong adsorption of C‐1983 in tissues appears to be a decisive factor in controlling movement of the herbicide in plants.Le comportement de la N'‐(4‐chlorophenoxy)‐phenyl‐NN‐dimethyluric (C‐1983) dans les terres et dans les plantes II. Absorption et migration dans les plantes
ON THE REGENERATION OF ROOT FRAGMENTS OF LEAFY SPURGE (EUPHORBIA ESULA L.)
Authors: RAJU M. V. S. , STEEVES T. A. , COUPLAND R. T. 
Published: July 2006

Summary. The roots of leafy spurge (Euphorbia esula L.) normally produce shoot buds abundantly near the soil surface but with decreasing frequency at increasing depths. By placing Fragments of roots collected from various depths in the soil in shallow flats in a glasshouse, it was demonstrated that root Fragments from all depths down to 2–8 m do not differ appreciably in rcgenerative capacity and this capacity is not dependent upon the presence of performed shoot buds. By collecting root fragments from the same stand throughout the growing season it was shown that regenerative capacity is lowest in June at the time of maximum flowering. The implications of these findings arc discussed in relation to the control of this species. Sur la régénération des fragments de racines de Euphorbia esula L.
CHEMICAL AND BIOLOGICAL PROPERTIES OF TWO NEW HERBICIDES—IOXYNIL AND BROMOXYNIL
Authors: CARPENTER K. , COTTRELL HELEN J. , DE SILVA W. H. , HEYWOOD B. J. , LEEDS W. G. , RIVETT K. F. , SOUNDY MARGERY L. 
Published: July 2006

Summary. The preparation of ioxynil, bromoxynil, and their salts is described, and information on solubilities and stability to storage is summarized. Although the toxicology of the herbicides is to be reported in greater detail, a preliminary statement is made here. Evidence of herbicidat activity under glasshouse conditions is indicated briefly, and supports the conclusion that both compounds are effective when applied to the foliage of a wide range of dicotyledon weed species. Seedlings of some weed species resistant to the phenoxy alkanoic acids are controlled under glasshouse conditions at doses as low as 0.125 lb/ac, and ioxynil has a wider range of activity than bromoxynil at these low doses. Graminaceous species tolerate 4–8 lb/ac of both herbicides without injury, and certain leguminous crops tolerate one or other herbicide at doses of 0.5–0.75 lb/ac. The contact action of the herbicides is rapid, there are also slower systemic effects, and seed germination is inhibited. In susceptible species the level of post‐emergence activity is shown to be influenced by the growth stage of the weed, the distribution of herbicide on the foliage, and environmental factors of which light intensity appears to be most important.Propriétés chimiques et biologiques de deux nouveaux herbicides: ioxynil et bromoxynil
A STUDY OF THE COMPETITIVE ABILITY OF CHENOPODIUM ALBUM L.
Authors: WILLIAMS T. 
Published: July 2006

Summary. Experiments arc reported that demonstrate that there is mutual interference between kale and Chenopodium album when grown in association. As the plants grow, those at high density, whether in mixtures or in pure stands, interfere with each other and individual plant weight and leaf area are reduced. By changing the time:of Introduction of one of the species into a mixture it was shown that kale suffered heavy mortality when C. album had an initial advantage. When kale was introduced before C. album the weed remained stunted but there was no mortality. The weed exerted an early effect of kale. The ability of C. album to interfere with kale, seems to be related to its plasticity. It is able to grow rapidly, to trap light effectively and even under adverse conditions to set seed. Etude sur le pouvoir de compétition de Chenopodium album L. I. Recherches sur la compétition enire les choux et C. album
THE ADSORPTION OF UREA AND SOME OF ITS DERIVATIVES BY A VARIETY OF SOILS
Authors: HANCE R. J. 
Published: July 2006

Summary. The absorption of urea and a number of its derivatives by different soils was investigated using a slurry‐type procedure. The materials could be listed in the following order of increasing tendancy to be adsorbed: urea, fenuron, methylurea, phenylurea, monuron, monolinuron, diuron. linuron, neburon and chloroxuron. Both N‐aryl and N‐alkyl substituents appeared to play a part in adsorption. Increasing chain length in the alkyl substituents and chloro‐ and chlorophenoxy substitution in the aryl substituent increased adsorption. There was no relationship between adsorption and water solubility.Organic matter content was the only soil property that could be related to adsorptive capacity. The evidence of Langmuir isothermal equilibrium plots suggests that only a fraction of the total soil surface is available for the adsorption of substituted ureas.L'adsorption Je l'uré de ses dérivés sur dfférents sols
SEED POLYMORPHISM AND GERMINATION
Authors: WILLIAMS J. T. , HARPER J. L. 
Published: July 2006

Summary. Achenes of Chenopodium album are polymorphic; four categories can be recognized visually, brown‐smooth, brown‐reticulate, black‐smooth and black‐reticulate. All four types may be borne by one plant. The polymorphic seeds differ in germination requirements, responding differently to chilling and nitrate application.Dormant seeds contain at least one extractable germination inhibitor. The inhibitor fails to act in the presence of added nitrate.Nitrate is replaceable by some other nitrogen compounds and by chlorate. Nitrate application stimulates germination of C. album in soil.The ecological significance of seed polymorphism and the relevance of polymorphism to the interpretation of germination tests are briefly discussed.
AN IMPROVED METHOD OF CONTROL OF PASPALUM CONJUGATUM WITH AMITROLE‐T AND PARAQUAT
Authors: HEADFORD D. W. R. 
Published: July 2006

Summary. Paraquat, amitrole‐T and disodiumn methylarsonate (DMA) were evaluated for the control of the stoloniferous grass Paspalum conjugatum in young rubber plantations in Malaya. The herbicides were tested alone, in mixtures and in split applications. Paraquat at 0–5 lb/ac gave good initial desiccation but regeneration was extremely rapid and repeated sprays of 0–25 lb/ac were required for a long period of suppression. Amitrole‐T at 15 lb/ac was very slow to act but gave complete kill after 10 weeks. DMA at 8–12 lb/ac gave marked suppression, but regeneration rapidly developed after 8 weeks. Mixtures of either amitrole‐T or DMA with paraquat gave less than the expected additive effects of the components, indicating an antagonistic action. Sub‐lethal rates of amitrole‐T or DMA applied to regenerating shoots after paraquat treatment gave results inferior to those from higher rates of the herbicides alone.When paraquat was applied 2 weeks after an initial sub‐lethal dose (0.375 lb/ac) of amitrole‐T, desiccation was rapid and complete eradication was achieved; this did not occur when a low rate of DMA was used as the first spray. In terms of both speed of kill and final effect, a split application of a low rate of amitrole‐T followed by paraquat was the most effective treatment. A possible explanation of the apparent synergism between amitrole‐T and paraquat applied in this way is advanced and suggestions for further work outlined. Une méthode améliorée pour la lutte centre Paspalum conjugatum avoc l'amitrole‐T et le paraquat
THE SPEED OF ATTAINMENT OF SORPTION EQUILIBRIA IN SOME SYSTEMS INVOLVING HERBICIDES
Authors: HANCE R. J. 
Published: July 2006

Summary. Measurements were made of the time taken for equilibrium to be established during adsorption and desorption under aqueous slurry conditions using monuron, linuron, atrazine and chlorpropham with a variety of adsorbents. An appreciable time was taken for equilibria to be established in adsorption processes, although with one exception, this period was 24 hr or less. Desorption processes were generally rather slower and in seven cases out of eighteen equilibrium was apparently not established in 72 hr. However, in all but two cases it seemed likely that the sorption process was reversible or nearly so.Possible explanations for differences of equilibrium times are discussed together with implications the results might have on the interpretation of leaching phenomena.Vitesse à laquelle est atteint I'équilibre d'adsorption et de désorption dans certains systèmes impliquant des herbicides
EFFECT OF PARAQUAT ON MICROBIAL ACTIVITIES IN SOILS*
Authors: TU C. M. , BOLLEN W. B. 
Published: July 2006

Summary. When paraquat was added to four different soils, nitrification was not appreciably affected but ammonification of soil organic‐matter nitrogen was slightly retarded. Carbon dioxide evolution as well as oxygen consumption was used as an index of metabolic activity of soil micro‐organisms and paraquat had a stimulatory effect at higher concentrations. Oxidation of added sulphur was slightly depressed. Paraquat decreased both the total mould and bacterial populations in Chehalis silt loam. After 30 days incubation the percentages of Streptomyces and Penicillia were markedly increased by most treatments but were little affected in Chehalis silt clay and Woodburn soils. Except for the temporary suppression of nitrification, paraquat had no significant influence on general microbial activities of importance to soil fertility. Some bimodal effects or toxicity inversions were observed with intermediate concentrations.Effet du paraquat sur les activités microbiennes dans les sols
RATE OF DETOXIFICATION OF 4‐AMINO‐3,5,6‐TRICHLOROPICOLINIC ACID IN SOIL
Authors: HAMAKER J. W. , YOUNGSON C. R. , GORING C. A. I. 
Published: July 2006

Summary. 4‐Aniino‐3,5,6‐trichloropicolinic acid was incubated at 70° F in thirteen different soils for periods of up to 2 years at a concentration range of 0–023–24 ppm. Losses varied from complete to non‐measurable by the bioassay technique employed. The percentage decomposed was generally greater for lower initial concentrations. The results were mathematically analysed in terms of zero‐order, half‐order, first‐order and Michaclis‐Menten kinetics. Half‐order and Mirhaelis‐Menten were found to be the kinetic expressions that most satisfactorily described the detoxification of the herbicide in soil.Taux de deloxification de l'acide 4‐amino‐3,5,6‐trichloropicolinique dans le sol
ZUR SELEKTIVITAT VON PHENMEDIPHAM ALS NACHAUFLAUFHERBIZID IN BETA‐RÜBEN*
Authors: ARNDT F. , KÖTTER C. 
Published: July 2006

Summary. Sugar beet are outstandingly tolerant to 3–methoxycarbonyIaminophenyl‐A′‐(3′‐methylphenyl) carbamate phenmedipham) and the difference in susceptibility between the main weeds prevalent in beet crops and the beet themselves can be used to obtain selective weed control. The herbicide is applied post‐emergence; action via the soil can be excluded as non‐existent.A test with twenty‐nine varieties of sugar beet and one variety of fodder beet showed no interaction between phytotoxicity and variety. No variety particularly susceptible to phenmedipham was found.Investigations on the mode of action and selectivity proved that phenmedipham is a strong inhibitor of the Hill reaction. There were no differences in the extent of inhibition of the Hill reaction in chloroplasts of a sensitive plant (mustard) as compared with a resistant species (sugar beet). Measurements of photosynthesis using infra‐red absorption methods and intact plants showed that it was inhibited in both sensitive and resistant species: the degree of inhibition, however, varied according to the species. In contrast to susceptible weeds, the resistant sugar beet and Amarantus relroflexus showed recovery in assimilation, and the recovery phases were significant. It can thus be concluded that sugar beet and A. retroftexus are able to inactivate phenmedipham.Sélectivité du phenmediphame, herbicide de post‐levée dans les cultures de de betteraves sucrièes
PLANT GROWTH STIMULATION BY SUBLETHAL CONCENTRATIONS OF HERBICIDES*
Authors: WIEDMAN STEVEN J. , APPLEBY ARNOLD P. 
Published: July 2006

Summary. Significant stimulation of root or shoot growth of oats (Avena sativa L.) resulted from pre‐emergence applications of eleven herbicides at sublethal doses. Two additional herbicides stimulated cucumber (Cucumis sativus L.) root growth. Several types of herbicides with different mechanisms of lethal action were represented. Three herbicides failed to stimulate plant growth significantly in these studies, although all of them have been observed to cause growth stimulation in other experiments. Studies on oat seedling respiration, photosynthesis, protein content, free amino acid content, and total available soluble carbohydrates failed to provide any consistent explanation for stimulation. These results provide further evidence of the validity of the Arndt‐Schulz hypothesis which states that all poisons are stimulatory at sublethal concentrations.Stimulation de la croissance des plantes par des concentrations sublétales d'herbiddesRésumé. Une stimulation significative de la croissance des racines ou des tiges de I'avoine (Avena sativa L.) a été provoquée par l'application en pré‐levée de onze herbicides à des doses sublétaies. Deux autres herbicides ont stimulé la croissance des racines de concombre. Plusieurs types d'herbicides possédant des mécanismes diffrénts d'action létale étaient représentés. Trois herbicides n'ont pas provoqué de stimulation significative de la croissance au cours de cette étude, bien qu'ils aient provoqué une stimulation dans d'autres expériences. Des recherches sur la respiration, la photosynthése, la teneur en protéines, en amino‐acides libres et le total disponible des hydrates de carbone solubles dans la plantule d'avoine n'ont fourni aucune explication logique de la stimulation. Ces résultats apportent une nouvelle preuve de la validité de l'hypothése d'Arndt‐Schulz selon laquelle tous les poisons ont un effet stimulant à des concentrations sublétaies.Förderung des Pflanzenwachstums durch Herbizide in sublethalen KonzentrationenZusammenfassung. Die Vorauflaufanwendung von elf Herbiziden in sublethalen Dosen förderte das Wurzel‐ und Sprosswachstum von Hafer (Avena sativa L.) signifikant. Zwei weitere Herbizide stimulierten das Wurzelwachstum bei der Gurke (Cucumis sativus L.). Es waren Herbizide aus verschiedenen Gruppen mit unterschiedlichem Mechanismus der lethalen Wirkung vertreten. Drei Herbizide förderten in diesen Studien das Wachstum nicht signifikant, obwohl eine solche fördernde Wirkung in anderen Experimenten beobachtet worden war. Untersuchungen der Atmung von Haferkeimlingen, der Photosynthese, des Proteingehaltes, des Gehaltes an freien Aminosäuren und der Gesamtmenge an löslichen Kohlenhydraten erbrachten keine einheitliche Erklärung für die Förderung. Diese Ergebnisse stützen die Gültigkeit der Arndt‐Schulz Hypothese, die besagt, dass alle Gifte in sublethalen Dosen stimulierend wirken.
SPATIAL GROWTH OF CYNODON DACTYLON (L.) PERS.*
Authors: HOROWITZ MENASHE 
Published: July 2006

Summary. Small sprigs of Cynodon dactylon (L.) Pers., were planted and grown without competition from weeds and crops for 2 1/2 years. The plant spread by means of above‐ground creeping stolons and subterranean rhizomes which could also emerge as aerial shoots, producing in their turn new stolons and rhizomes. Initially there was linear extension of stolons and rhizomes, following which gaps in the sod were filled by stolon branching and new shoots. There was no preferential direction of stolon elongation and established sods developed an approximately circular shape and expanded concentrically. The rate of increase in sod area was similar in both years of observation but radial extension was smaller in the second year than in young plants.The mean sod area was 25 m2 after 2½ years of growth, and mean monthly area increment was 0·9 m2. Growth almost stopped in the cold season and exceeded 2 m2 per month in the summer. The plants had extended up to 3·9 m from the plant centre after 2 1/2 years. The number of flowering culms per sod, produced only in the warm season, was directly proportional to sod area; seeds were infertile in the Newe Ya'ar area.After 2½ years of growth about 70% of the rhizome dry weight was present in the upper 20 cm of soil. Few rhizomes penetrated deeper than 40 cm. More than 60% of the rhizomes were present within 1 m radius of the plant centre and 90% were present within 2 m radius. Croissance spatiale de Cynodon dactylon (L.) Pers.