bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dégradation catalytique de carbamates herbicides deposés sur bentonites homoioniques. I. Cas du barbane
Authors: SABADIE J. , BASTIDE J. , COSTE C. M. 
Published: July 2006

RásumáLa dégradation chimique en phase sèche du barbane a étéétudiée après dèpôt à température ambiante sur diverses bentonites homoioniques (Cu2+; Ag+). La bentonite Ag+ présente une réactivité particulièrement intéressante. Le schéma général de cette dégradation a étéétabli.
Effect of CGA 123407 as a safener for pretilachlor in rice (Oryza sativa L.). Recordings of elongation rates of single rice leaves
Authors: CHRIST R. A. 
Published: July 2006

SummaryThe elongation rates of single attached leaves of rice (Oryza saliva L.) were recorded. The effect of pretilachlor on the elongation rates and the safening effect of CGA 123407 [4, 6‐dichloro‐2‐phenyl‐pyrimidine] were evaluated. Both chemicals were applied to the roots in a nutrient solution.Pretilachlor reduced leaf elongation in concentrations as low as 300 μg−1 (9–6 × 10−7 M) but. for combination trials with the safener, 3 mg 1−1 (9–6 × 10−6 M) was used. in combination with pretilachlor the safener prevented damage in very low concentrations. The ratio of pretilachlor to safener, 30:1, was sufficient when both chemicals were given to roots in nutrient solution, although for field work the ratio of 3:1 is recommended. The safener alone did not influence the elongation rate of rice leaves in the concentrations used. When pretilachlor was given to the roots and CGA 123407 to the shoot, some delay in the herbicidal action was recorded but even with high concentrations of the safener no continuous safening effect was achieved.CGA 123407 was also effective when given previous to the herbicide. This proved true even with a 2‐day interval between safener uptake and application of the herbicide. When pretilachlor was given first, the safener effected recovery to various degrees when given 1–4 days after the herbicide application.When pretilachlor was given for a limited period of time only (1–3 days) and was subsequently removed from the nutrient solution, recovery of the plant occurred. It is speculated that the safener either helps this recovery or else competitively prevents the herbicide from occupying the sites of action or from keeping them occupied for a long period of time.
Competition between annual weeds and vining peas grown at a range of population densities: effects on the weeds
Authors: LAWSON H. M. , TOPHAM P. B. 
Published: July 2006

SummaryLinear regression of dry weight of weeds against crop density, together with the use of diversity indices and principal component analysis were used to derive information about changes in the behaviour of annual weeds over the growing season and in response to a wide range of crop densities in vining peas Pisum sativum L. Using linear regression it was possible to quantify reductions in weed dry weights per unit increase in crop plant density The ‘weed losse’ factor was acceptably consistent between experiments. Indices examining richness and evenness showed that numbers of weed species declined with increasing crop density and as the season progressed, but although species evenness became less at successive sampling dates the presence of a pea crop, whatever its density, did not radically alter the composition of the weed flora. Principal component analysis demonstrated that although there was competition within the weed flora, the crop did not replace the dominant weed species on high density plots, but reduced growth of all weed species alike.
Temperature requirements for germination of buried seeds of Aethusa cynapium L.
Authors: ROBERTS H. A. , BODDRELL J. E. 
Published: July 2006

SummaryFreshly‐collected mature mericarps of Aethusu cynapium were dormant, but some germinated at alternating (16 h low/8 high) temperatures when the seed coverings were removed. Burial during winter increased percentage germination and the temperature range over which it took place. In late spring the range narrowed, first at low and then at higher temperatures, widening again in autumn. Moist storage at both low (4°C) and high (30°C) temperatures overcame dormancy, but exposure to 30°C inhibited subsequent germination at low temperatures. Germination of intact mericarps was consistently lower than that of de‐coated seeds. The cyclic change in dormancy status of the seeds appears to interact with the restricting effects of the seed coverings and perhaps other factors in determining the consistent pattern of spring emergence in A. cynapium.
Tolerance of spring wheat (Triticum aestivum L.) to trifluralin deep‐incorporated in the autumn or spring
Authors: O'SULLIVAN P. A. , WEISS G. M. , FRIESEN D. 
Published: July 2006

SummaryField experiments at Lacombe on a Ponoka loam soil (9·6% organic matter) during 1982 and 1983 investigated the tolerance of spring wheat (Triticum aestivum L.) cv. Neepawa in a weed free situation to trifluralin applied at 0·0–3·0 kg ai ha−1 in the autumn or spring and incorporated to a depth of 10 cm. Rates of trifluralin above 1·0 kg ai ha−1 applied in the autumn or spring reduced the percent stand of wheat compared to an untreated control. Two weeks after emergence the crop showed 37 or 47% injury indicated by delayed growth, following application at 1·0 kg ai ha−1 in the autumn or spring, respectively. The wheat recovered throughout the course of the growing season. At harvest, trifluralin applied in the autumn or spring at rates below 1·0 kg ai ha−1 caused a yield increase while higher rates caused a yield decrease compared to the untreated control. Spring application caused a greater yield loss than autumn application. The tolerance of spring wheat to trifluralin at rates required for weed control (1·1 kg ai ha−1 or higher) on this soil type is marginal.
Improved control of Stellaria media (L.) Vill in leys with Trifolium repens, using bentazone and benazolin with additives
Authors: TURNER D. J. 
Published: July 2006

SummaryIn pot experiments, mixtures of ammonium sulphate with surfactants or oil additives increased the phytotoxicity of commercially formulated bentazone (‘Basagran’) to Stellaria media (chickweed). Ammonium sulphate with a proprietary oil adjuvant Actipron had similar effects with benazolin potassium salt, but not with an ethyl ester formulation of benazolin. The phytotoxicity of bentazone and benazolin salts to Trifolium repens (white clover) and Lolium perenne (perennial ryegrass) was almost unaffected by these additives. In a field experiment, a mixture of ammonium sulphate with Actipron improved the control of S. media by bentazone and benazolin salts.Oils and surfactants markedly increased rates of entry of 14C bentazone into leaves of S. media, white clover and Chrysanthemum segetum. Ammonium sulphate sometimes had similar effects but on other occasions reduced uptake. In some circumstances the additives apparently interacted synergistically, to increase uptake of labelled herbicide into the leaf or to enhance its transport within the plant. In these test species, differential absorption of bentazone could not explain differences in species susceptibility, suggesting that the main cause of resistance was the ability of plants to degrade the herbicide.
Population studies on Pennyroyal Mint (Mentha pulegium L.) I. Germination and seedling establishment
Authors: PANETTA F. D. 
Published: July 2006

SummaryVery few seeds of M. pulegium germinated in the absence of light, but relatively high levels of germination were attained over a wide range of temperatures when seeds were exposed to light. This response to temperature was reflected in patterns of seedling appearance in several field sites, where new plants were recorded between autumn and early summer. Initial mortality rates differed between cohorts which occurred within and outside a pasture community, and were higher in the presence of pasture species. Seedlings survived prolonged periods of inundation and new plants were detected under water to a depth of 10 cm. The capacity for growth under water is considered to be an important aspect of the ability of M. pulegium to invade and persist in sites which are flooded seasonally.
Population studies on Pennyroyal Mint (Mentha pulegium L.) II. Seed banks
Authors: PANETTA F. D. 
Published: July 2006

SummaryAn investigation of seed banks found under populations of M. pulegium located within and outside pasture systems revealed that seed densities were sixteen times greater when this species occurred in pastures. The sizes of seed banks were not positively related to current seed production, but larger seed banks appeared to be associated with higher levels of soil disturbance arising from trampling by grazing stock. Densities of buried seed were very high under pasture populations (range 55 000–176 000 m−2), which illustrates the impracticality of attempts to eliminate M. pulegium from this type of community.
Unrestricted growth, tuber formation and spread of Cyperus esculentus L. in Zimbabwe
Authors: LAPHAM J. 
Published: July 2006

SummaryThe unrestricted growth and clonal spread from individual tubers of Cyperus esculentus L. were studied in Zimbabwe. Clonal material, collected from the Trelawney area, was grown in a square arrangement in the field with a 5 m spacing between original tubers. Growth was recorded at approximately monthly intervals for 2 years. The natural logarithm of clonal spread (m per month) was positively correlated to temperature and rainfall. Most growth occurred from November to March, a period of optimal moisture and temperature conditions. There was little growth during the remainder of the year. The changes in clonal spread during the year are expressed mathematically and incorporate two parameters of growth; one describes the rate of growth and the other predicts the radius once growth ceasesTuber numbers increased exponentially from December‐April, the rate of tuber production being greater in the first than in the second year of growth. Tuber production was greatest during March, April and December, 1980. Dormancy of the tubers decreased during the cooler months from May to August. The value of describing unrestricted clonal growth, and conditions favouring tuber production, are discussed.
Influence of temperature on the activity of AC 222,293 against Avena fatua L. and Alopecurus myosuroides Huds.
Authors: PILLMOOR J. B. 
Published: July 2006

SummaryFoliage applications of AC 222,293 were more active against Alopecurus myosuroides Huds. plants growing at high (26/16°C day/night) compared to either medium (16/10°C) or low (11/7°C) temperatures. Soil activity was unaffected by temperature. Enhanced activity against A. myosuroides required exposure to the high temperatures for only 24 h immediately post spraying and correlated with the accumulation of greater levels of the biologically active acid in the apical meristem region during this period.Both foliage and soil activity of AC 222,293 were greatest against Avena fatua L. plants growing at medium (16/10°C) compared to either high (26/16°C) or low (11/7°C) temperatures. Foliar activity decreased slowly with increasing periods of high temperatures post spraying and then only at doses lower than those recommended for field use. Reduced performance at the high temperatures correlated with lower levels of the biologically active acid in the meristem region, despite greater uptake and translocation. This was due to increased metabolism of the parent herbicide and formation of metabolites other than the free acid.
Germination of Chromolaena odorata (L.) K. & R. achenes: effect of temperature, imbibition and light
Authors: ERASMUS D. J. , VAN STADEN J. 
Published: July 2006

Summary: Résumé: Zusammenfassung Chromolaena odorata (L.) K. & R. (= Eupatorium odoratum L.) has invaded large areas of the coastal belt of Natal province in South Africa. Propagation is predominantly by means of windborne achenes. The germination of these achenes was investigated. Of the temperatures tested, alternating 15/30°C was optimal for germination. These achenes are positively photoblastic and an imbibition period prior to exposure was required to sensitize the achenes to light. The promotive effect of red light on the germination of imbibed achenes could be reversed by subsequent exposure to far‐red light while the inhibitory effect of far‐red light could be nullified by a subsequent red light treatment. This is typical of a phytochromemediated germination response. Germination d'akènes de Chromolaena odorata (L.) K. & R.: effets de la température, de l'imbibition el de la lumière Chromolaena odorata (L.) K. & R. (= Eupatorium odoratum L.) a envahi de grandes superficies dans le littoral de la province de Natal en Afrique du Sud. La plante se répand surtout par moyen d'akènes portés par le vent. La germination de ces akènes a fait l'objet d'une étude. Parmi les températures essayées, 15/30°C s'est révélée optimale pour la germination. Les akènes font preuve d'une photoblasticité positive et pour les sensibiliser à la lumière, il leur faut une période d'imbibition avant de les y exposer. La promotion de germination provoquée par la lumière rouge chez les akènes imbibés a pu etre inversée par une exposition ultérieure à la lumière extrême‐rouge (700 à 750 nm) tandis que l'effet inhibiteur de celle‐ci s'est trouvé annulé par un traitement ultérieur à la lumière rouge. Cette réaction est caractéristique d'une germination réglée par le phytochrome. Die Keimung von Achaenen von Chromolaena odorata (L.) K. & R.: der Einfluss von Temperatur, Quellung und Licht. Chromolaena odorata (L.) K. & R. (= Eupatorium odoratumL.) hat sich auf grossen Flächen des Küstengürtels der Provinz Natal (Südafrika) ausgebreitet. Durch den Wind verbreitete Achaenen sind hauptsächlich für die Vermehrung verantwortlich. Thema der vorliegenden Untersuchung war die Keimung dieser Achaenen. Alternierende Temperaturen von 15° und 30°C waren optimal für die Keimung. Die Achaenen waren positiv photoblastisch; eine Quellungsperiode war notwendig um die Achaenen für die Lichtreaktion zu sensibilisieren. Der die Keimung vorgequollener Achaenen fördernde Einfluss von Rotlicht konnte durch eine nachfolgende‘Fern‐Rot'‐Exposition rückgängig gemacht werden. Hingegen wurde der Hemmungseffekt von ‘Fern‐Rot’ durch eine darauffolgende Rotlicht‐Exposition aufgehoben. Dieser Befund ist charakteristisch für eine phytochromregulierte Samenkeimung.
Quelques aspects de la germination des caryopses de Leersia oryzoides (L.) Sw.
Authors: ROSA MARIA L. , CORBINEAU FRANÇOISE 
Published: July 2006

Résumé: Summary: ZusammenfassungLes semences de Leersia oryzoides (L.) Sw. germent mal au moment de leur récolte parce qu'elles sont dormantes. Leur germination exige des températures élevées, mais une alternance de températures fraîches et de températures élevées est plus favorable. La dormanee résulte en partie de l'action inhibitrice des glumellcs qui sont capables de fixer de l'oxygène, ce qui réduit la quantité de ce gaz disponible pour le grain. Elle s'élimine très lentement au cours de la conservation au sec ou pendant un prétraitement au froid humide. A 20°C, les caryopses nus germent mieux en hypoxie (3 à 15% d'02) qu'à l'air et un excès d'oxygène est très nocif. A 30°C, par contre, leur germination reste possible dans des atmosphères enrichies en ce gaz (50 à 100%d'02). Les caractéristiques physiologiques de la dormance et de la germination de ces semences sont discutées en relation avec l'adaptation de la mauvaise herbe à son environnement. Some aspects of the germination of caryopses of Leersia oryzoides (L.) Sw.Freshly harvested seeds of Leersia oryzoides (L.) Sw. show low germination as a result of dormancy. Germination requires high températures but is improved at a diurnal alternation between high and low temperature. Dormancy is partially due to inhibition by the glumes which are capable of oxygen uptake and thus reduce the amount of oxygen available to the grain. This dormancy is gradually reduced during dry storage, or low temperature incubation. Germination of naked caryopses at 20°C is higher at sub‐aimospheric 02 (3–15%) than in normal air, while excess oxygen is noxious. At 30°C, however, germination takes place even in 02‐enriched atmospheres (50–100%), The physiological characteristics of dormancy and of germination of this species are discussed in relation to the adaptation of this weed to its environment. Uber die Keimung der Karyopsen von Leersia oryzoides (L.) Sw.Die Samen von Leersia oryzoides (L.) Sw. befinden sich zur Zeit der Ernte in einer Ruhephase; sie keimen deshalb zu diesem Zeitpunkt Schlecht. Zur Keimung sind höhere Temperaturen erforderlich. Ein Wechsel zwischen niederen und höheren Temperaturen ist jedoch noch günstiger. Diese Ruhezeit wird z.T. durch eine Hemmwirkung der Deckspelzen, welche Sauerstoff fixieren können, verursacht, wodurch die für das Korn zur Verfügung stehende Sauerstoffmenge reduziert wird. Während einer Kühllagerung oder einer Vorbehandlung in feucht‐kalter Athmosphäre verschwindet die Ruheperiode langsam. Bei 20°C keimen die nackten Karyopsen in Gegenwart geringer Sauerstoffmengen (3–15% 02) besser als in normal zusammengesetzter Luft, während ein erhöhter 02 Gehalt sogar schädlich wirkt. Bei 30°C hingegen, ist die Keimung auch in mit Sauerstoff angereicherter Athmosphäre (50–100%) möglich. Die physiologischcn Grundlagen von Samenruhe und Keimung werden in Beziehung mit der Anpassung dieses Unkrautes an seine Standorte diskutiert.
Chloroform‐soluble fraction from soyabean (Glycine max (L.) Merr.) leaves following herbicide applications
Authors: SOUZA I. F. , WILLIAMS J. L. 
Published: July 2006

Summary: Résumé: ZusammenfassungThe research reported here had the objective of evaluating the effect of trifluralin (2,6‐dinitro‐N,N‐dipropyl‐4‐trifluoromethylaniline), bifenox (methyl‐5‐(2,4‐dichlorophenoxy)‐2‐nitrobenzoate) and vernolate (S‐propylN,N‐dipropyl‐(thiocarbamate)) on soyabean (Glycine max (L.) Merr.) leaf wax production. The applications of vernolate at 3.36 and 5.4 kg ai ha−1 reduced the chloroform‐soluble extraction of the soyabean leaves to 90% and 88%, respectively, under glasshouse conditions and to 83% and 81%, respectively, under field conditions, when compared to the untreated control taken as 100%. Trifluralin, bifenox and vernolate at 1.68 kg ai ha−1 did not reduce leaf wax production. Effet de traitements herbicides sur la fraction soluble dans le chloroforme des feuilles de soja (Glycine max. (L.) Merr.)Le présent travail a pour but d'évaluer l'effet de la trifluraline (2,6‐dinitro‐N,N‐dipropyl‐4‐trifluor‐omethylaniline), du bifénox (méthyl‐5‐(2,4‐dichlorophenoxy)‐2‐nitrobenzoate) et du vernolate (S‐propyl‐N‐N‐dipropyl thiocarbamate) sur la production des cires foliaires chez le soja (Glycine max (L.) Merr.). L'application de vernolate à 3,36 et 5,04 kg m.a. ha−1 a réduit l'extrait chloroformique foliaire à 90 et 88%, respectivement, chez des plantes cultivées en serre, et à 83% et 81%, respectivement, chez des plantes cultivées au champ, par rapport aux 100% trouvées chez les téemoins non traités. La trifluraline, le bifénox et le vernolate à la dose de 1,68 kg/ha n'ont pas réduit la production de cires foliaires.Ueber die chloroformlösliche Fraktion von Sojabohnenblättern nach HerbizidapplikationenIn den hier publizierten Versuchen wurde der Einfluss von Trifluralin (2,6‐dinitro‐N,N‐dipropyl‐4‐trifluoromethylaniline), Bifenox (Methyl‐5‐(2,4‐dichlorphenoxy)‐2‐nitrobenzoate) und Vernolat (S‐propyl N,N‐thiocarbamate) auf die Ausbildung der Wachsschicht auf den Blättern von Soyabohnen (Glycine max (L.) Merr.) untersucht. Die Anwendung von 3,36 und 5,04 kg ai ha−1 Vernolat verminderte die durch Chloroform extrahierbaren Anteile von Soyablättern im Gewächshaus auf 90 resp. 88%, in Freilandversuchen auf 83 resp. 81%, im Vergleich zu den mit 100% eingesetzten Extrakten aus unbehandelten Pflanzen. Trifluralin, Bifenox und 1, 68 kg ai ha−1 Vernolat verursachten keine Verringerung der Wachsproduktion der Blätter.
The demography of Datura ferox (L.) in soybean crops
Authors: BALLARÉ C. L. , SCOPEL ANA L. , GHERSA C. M. , SÁNCHEZ R. A. 
Published: July 2006

SummaryThe emergence, survival, seed production and seed dispersal of Datura ferox was studied in soybean fields in 1982–1983 and 1984–1985. Most seedling emergence occurred within one month of crop sowing. Later germination, associated with inter‐row cultivation, represented 4–26% of the total seedlings, and none survived to seed production. Only 5% of the first cohort in 1982–1983, and 7% in 1984–1985, survived to seed production; it was independent of initial density. Although weed density was greatly reduced by control measures, negative relationships were observed between peak seedling density and plant height, stem diameter, number of ramifications, number of reproductive structures and seed production per plant. Only a small proportion of seeds (about 1%) were shed prior to soybean harvest. Combine harvesters collected more than 90% of capsules, but between 7% and 40% of the seeds were returned to the field. Seed viability was unaffected by passing through the machine. The patterns of seed dispersal varied depending on the design of the combine harvester. Two models shed seeds between 0 m and 21 m from their source, but another shed seeds between 0 m and 98 m. Calculations, based in life history parameters, showed that weed seed production would increase more rapidly if the seeds were dispersed during crop harvesting than if they arc not, even when the return of seeds to the soil by the combine is not large.
Evaluation of a simulation model for prediction of herbicide movement and persistence in soil
Authors: WALKER A. 
Published: July 2006

SummaryThe movement and persistence of residues of propyzamide, linuron, isoxaben and R‐40244 were measured in a sandy loam soil in field experiments prepared in spring and autumn. None of the herbicides moved to depths greater than 12 cm in the soil during the winter period, following application in autumn, and none moved more than 6 cm in the soil, following application in spring. The general order of persistence of total soil residues was isoxaben > linuron = R‐40244 > propyzamide. Appropriate constants to describe the moisture and temperature dependence of degradation were derived from laboratory incubation experiments and used with measurements of the strengths of adsorption of the different herbicides by the soil, in a computer model of herbicide movement. The model, in general, gave good predictions of total soil residues, but overestimated herbicide movement, particularly in winter. Measurements of herbicide desorption from the soil at intervals, during a laboratory incubation experiment, demonstrated an apparent increase in the strength of adsorption with time. When appropriate allowance was made for these changes in adsorption in the computer model, improved predictions of the vertical distribution of the herbicide residues were obtained.
Retention, absorption, translocation and distribution of sethoxydim in monocotyledonous and dicotyledonous plants*
Authors: CAMPBELL J. R. , PENNER D. 
Published: July 2006

SummaryQuackgrass [Elymus repens (L.) Gould =Agropyron repens (L.) Beauv.] and barnyardgrass [Echinochloa crus‐galli (L.) Beauv.] were more than one hundred times more susceptible to sethoxydim than alfalfa (Medicago sativa L. 'Saranac') or navybean (Phaseolus vulgaris L. 'Seafarer'). Uptake of sethoxydim From soil following post‐emergence applications caused negligible reduction in E. crus‐galli fresh weight. More than 80% of foliar‐applied 14C‐sethoxydim was absorbed within 6 h in all species. Translocation occurred in all species with accumulation of 14C in rapidly growing plant tissues. Translocation to the roots was less than 8% of total in all species. Most of the extracted 14C initially partitioned into an ethyl acetate‐soluble fraction. The proportion of 14C in the ethyl acetate‐soluble fraction decreased with time with a concomitant increase of that in the insoluble fraction. Differences in the quantity of 14C in the ethyl acetate‐soluble fraction did not account for the observed selectivity.