bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the germination and emergence response to temperature and soil moisture of Avena fatua and A. sterilis
Authors: FERNANDEZ‐QUINANTILLA C. , ANDUJAR J. L. GONZALEZ , APPLEBY A. P. 
Published: July 2006

Summary:Seeds of Avena fatua L. and )A. sterilis L. were germinated under a wide range of temperatures (5–30°C) and osmotic potentials (−25 to −1400 KPa) in order to characterize their responses to these two environmental factors. Although both species behaved similarly at moderate temperatures, different responses were observed at the two extremes. )A. sterilis germinated and emerged in a higher proportion than A. fatua at temperatures below 10°C but the opposite was true at temperatures above 20°C. Although the rates of these two processes were similar in both species up to 18°C, above this temperature the germination and emergence of )A. sterilis was considerably delayed in comparison with that of A. fatua. The effect of decreasing osmotic potentials in reducing the germination was more pronounced in A. sterilis than in A. fatua. However, no differences were observed in the emergence responses of either species. The adaptative advantages of these characteristics and their relationship with the geographic distribution of the two species is discussed.
Influence of environmental factors on the weed flora in crops in the Guadalquivir Valley
Authors: SAAVEDRA M. , GARCIA‐TORRES L. , HERNANDEZ‐BERMEJO E. , HIDALGO B. 
Published: July 2006

Summary:The study was conducted on the weed flora of the main irrigated crops of the Guadalquivir Valley. The TWINSPAN (Two Way Indicator Species Analysis) method was applied for each crop separately to all the species present as well as to their degree of infestation. The results indicated that soil texture may markedly influence the flora, whereas the effects of pH and carbonate content were less important. The climatic differences found in the three areas studied were of little importance. The type of irrigation markedly influenced the flora, although it was always related to edaphic factors, especially texture and slope.In general, the weed flora found in the crops can be divided into two communities. One is characterized by species such as Ridolfia segetum, Picris echioides, Phalaris brachystachys, Phalaris paradoxa and Chrozophora tinctoria and the second by Capsella bursa‐pastoris, Cyperus rotundus, Paspalum paspalodes, Digitaria sanguinalis, Sorghum halepense and Portulaca oleracea. The first community comprises weeds in the higher altitudes, further away from the riverbed, with a soil of clayey texture, a high slope and irrigated with sprinklers. The second community comprises the flora of flat areas, with sandy soils, located in the middle and low river terraces and furrow irrigated.
The role of light and alternating temperatures on germination of Polygonum aviculare seeds exhumed on various dates
Authors: BASKIN J. M. , BASKIN CAROL C. 
Published: July 2006

Summary:The annual dormancy cycle was investigated in buried seeds of Polygonum aviculare L. exposed to natural temperature changes in Lexington, Kentucky, U.S.A. Seeds were exhumed monthly from December 1984 to February 1987 and tested in light (14‐h daily photoperiod) and continuous darkness at 12/12‐h daily alternating temperature regimes of 15/6, 20/10, 25/15, 30/15 and 35/20°C. During autumn and winter, seeds became non‐dormant, and in March 1985 they germinated to 95‐100% at all thermoperiods in light and to 7‐61% in darkness. Seeds remained non‐dormant during spring but became more specific in their germination requirements in early summer. During July and August 1985, seeds germinated to 17‐53% in light at 30/15 and 35/20°C but to 0‐10% at all other test conditions. By September, about 65% of the seeds were dormant, but the others were able to germinate under the higher alternating temperatures in light. A similar seasonal cycle was recorded in the following year through to the spring of 1987. The results confirm the seasonal pattern of dormancy in this species (Courtney, 1968) but indicate that alternating temperatures combined with light are important in determining germination potential in P. aviculare.
Orobanche ramosa L. (broomrape) control in tomato (Lycopersicon esculentum Mill.) with chlorsulfuron, glyphosate and imazaquin
Authors: KOTOULA‐SYKA E. , ELEFTHEROHORINOS I. G. 
Published: July 2006

Summary:Chlorsulfuron, giyphosate and imazaquin were evaluated in pot and field studies for their efficacy in controlling broomrape (Orobanche ramosa L.) in tomato (Lycopersicon esculentum Mill.) in Northern Greece. All herbicides were applied four to five weeks after tomato transplanting, when the crop was at early flowering stage and broomrape had started to develop underground attachments. The number of emerged broomrape shoots and underground attachments were less affected by herbicide treatments than the dry weight, suggesting that the herbicides suppress the growth of broomrape rather than kill its underground organs. In the pot experiments, chlorsulfuron applied at 5 g AI ha−1 was the most effective treatment for broomrape control and the least toxic to the crop. Imazaquin and glyphosate applied at 37 and 180 g AI ha−1, respectively, controlled broomrape but imazaquin reduced crop yield. In the field, similar rates of glyphosate and higher rates of imazaquin were not toxic to the crop but were less effective on broomrape. Chlorsulfuron applied at 10 g AI ha−1 controlled broomrape emergence by 88%. When the herbicide was applied twice (5+10 g AI ha−1), it gave complete control of broomrape but delayed crop maturity. The yield of tomato was not increased as a result of these treatments because of low broomrape infestation and a short competition period.
Imazaquin, ein aussichtsreiches Herbizid für die Bekämpfung von Seiden–Arten (Cuscuta spp.) in Sojabohnen
Authors: LIU Z. O. , FER A. , LECOCO F. M. 
Published: July 2006

Résumé:L'imazaquine, un herbicide systémique, appliqué sur les feuilles de Phaseolus aureus parasité par Cuscuta lupuliformis est transporté dans la cuscute et fortement accumulé dans la partie apicale des tiges de ce parasite. Des résultats similaires sont obtenus avec le couple soja—Cuscuta australis. L'herbicide est rapidement dégradé dans le soja, mais actif sur la cuscute dont il inhibe la division cellulaire. La systémie phloémienne de l'imazaquine, sa sélectivité physiologique vis à vis du soja ainsi que son efficacité sur la cuscute font que cet herbicide est un produit prometteur pour la lutte curative contre la cuscute dans le soja, comme le montrent les essais préliminaires réalisés en serre.
Vegetative Bestimmungsmerkmale für Eragrostis‐Arten, die als einjährige Unkrautarten in Nordkamerun auftreten
Authors: LE BOURGEOIS T. , KAMGA F. 
Published: July 2006

Résumé:Neuf espfèces d'Eragrostis annuelles, adventices des cultures du Nord Cameroun sont différenciées à partir de quelques critères de l'appareil végétatif: E. viscosa, E. namaquensis, E. gangetica, E. turgida, E. pilosa, E. tremula, E. aspera, E. ciliaris, et E. cilianensis.
Soil metabolism of the herbicide napropamide in cereals, maize, sugar beet and vegetable field replacement crops
Authors: ROUCHAUD J. , GUSTIN F. , VAN HIMME M. , BULCKE R. , BENOIT F. 
Published: July 2006

Summary:The metabolism of the herbicide napropamide has been studied in the field in the soil of replacement crops (cereals, corn, sugar beet, potato and several vegetables). Napropamide was soil applied in the autumn and the soil left fallow during the winter. Crops were sown in April of the following year and simulated the replacement crops that are grown in the event of failure of the first autumn‐sown crop. Trials were made twice, i.e. during the 1987‐1988 and 1988‐1989 crop seasons. The soil metabolism of napropamide was also studied in a rose nursery. Napropamide was transformed by microbiological processes in the soil into the corresponding monoethylamide and acid. These compounds did not generally accumulate in the soil, and their individual concentrations did not exceed that of residual napropamide during the observed growing seasons. The kinetics, metabolic pathways and agricultural implications of the herbicide are briefly discussed.
A review of the ecology and control of thistles in Australia
Authors: SINDEL B. M. 
Published: July 2006

Summary:Studies on the ecology and control of thistles in Australia, particularly those related to pasture improvement, are reviewed, and the results used to interpret increases and changes in thistle dominance. Several hypotheses, based on ecological differences in the thistles, their life cycles and changes in the soil/seed environment may explain the changing species incidence in the field, and it is postulated that, within a restricted group of competing thistle species, it may be more meaningful to interpret these ecological differences in terms of ‘tolerance of unfavourable conditions’ than in terms of ‘optimal requirements’.Alternative strategies for the control of thistles, including pasture competition, grazing management, the utilization of high soil fertility, and chemicals, are also assessed. It is re‐emphasized that the aim of any long‐term programme to control thistles, with or without the release of biological agents, should be the establishment and/or maintenance of a vigorous perennial pasture. The relative importance of different thistle species in Australian pastures and the ecology and dynamics of soil seed banks are identified as important areas for future thistle research.
Dynamics of competition between wild oats (Avena fatua L.) and winter cereals
Authors: COUSENS R. D. , WEAVER S. E. , MARTIN T. D. , BLAIR A. M. , WILSON J 
Published: July 2006

Summary:This study examined the effects of competition on the growth of Avena fatua, winter wheat and winter barley. Plants were sampled at frequent intervals from replacement series experiments at two contrasting sites in the U.K. A. fatua was much slower to establish than the two cereals, but thereafter exhibited a faster rate of growth. In monoculture, it took a considerable time for A. fatua to reach a size equal to that of the cereals, but by the end of the experiments it was the largest of the three species. The change‐over from cereal dominance in mixtures to A. fatua tiominance was rapid, and in three cases coincided with cereal flag leaf emergence. In the fourth case, it appeared to coincide with the art of canopy height extension. At one site the rder of competitiveness at anthesis was A. fatua= barley>wheat, and at the other site the order was A. fatua>wheat>barley. In order to explain and predict differences between years and sites, more studies are required on morphological development in relation to abiotic variables.
An in‐vitro growth system for studying the parasitism of cowpea (Vigna unguiculata) by Striga gesnerioides
Authors: LANE J. A. , BAILEY J. A. , TERRY P. J. 
Published: July 2006

Summary:An in‐vitro growth system for investigating the behaviour of S. gesnerioides on cowpea has been developed. The roots of young cowpea plants were spread over glass fibre filter paper in a shallow plastic tray, and a known number of germinated Striga seeds were placed on the cowpea root surface. This allowed the infection process of the parasite to be quantified. Good access to the host‐parasite association enabled the entire infection process to be easily monitored and tissue removed for cytological studies. Observations revealed for the first time that contact of S. gesnerioides radicles with host roots stimulated the development of radicular hairs and swelling of the tip of these radicles. Furthermore, penetration of cowpea roots by Striga was shown to be localized and to cause very little damage to the host roots. Swollen parasite tubercles developed on the surface of the roots only after the host stele had been penetrated by invading Striga cells. This growth system is suitable for in‐vestigating the mechanisms of host resistance. and also for rapidly screening cowpea germplasm for new sources of resistance to the Parasite. Resistant cowpea cultivars offer the best potential solution for control of this Parasite.
Study of diuron in soil solution by means of a novel simple technique using glass microfibre filters
Authors: GAILLARDON P. , FAUCONNET F. , JAMET P. , SOULAS G. , CALVET R. 
Published: July 2006

Summary:Retention by a glass fibre filter of the liquid phase of a clay loam soil treated with 14C‐diuron provides a novel method for analysis of the herbicide in soil solution. At 26.3% (w/w) soil moisture content, less than 10% of the applied diuron was found in solution, and this percentage decreased slightly with diuron dose. The herbicide was rapidly adsorbed on soil during the first day, but adsorption continued and the concentration of diuron in solution could be further reduced by 36–50% during the following 6 days. Drying the soil after treatment, with possible crystallization of herbicide applied at high doses, tended to fix the solution concentrations. Ethanol (3% v/v) in soil water favoured herbicide dissolution. Increasing soil moisture to 36.3% (w/w) slightly decreased the concentration of the herbicide in solution, but increased the percentage held in solution. Frost and a drying‐rewetting cycle had little or no subsequent effect on diuron concentration in soil solution.
A model for prediction of yield response in weed harrowing
Authors: RASMUSSEN J. 
Published: July 2006

Summary:A model is presented to describe crop yield response in weed harrowing. The selectivity of harrowing, crop yield response to soil covering, and the competitive strength of the weeds are all variables in the model, which is derived from the hyperbolic yield‐density relationship, and therefore accounts for the effects of weed density. An advantage of the modelling approach is that the yield response can be separated into two parts, one derived from the positive weed‐killing effect of harrowing, and the other derived from the negative crop‐covering effect. Simulation runs based on experimental data showed that crop damage, when it occurs, cannot be ignored, and may sometimes even dominate the positive weed‐killing effect. Possible scientific and practical applications of the model are discussed.
Induction of Striga seed germination by thidiazuron
Authors: BABIKER A. G. T. , PARKER C. , SUTTLE J. C. 
Published: July 2006

Summary: Résumé: ZusammenfassungThidiazuron at 0.1 to 10 mg 1−1 induced concurrent germination and haustorium initiation in Striga asiatica (L.) Kuntze and S. hermonthica (Del.) Benth, but it had no effects on S. gesnerioides (Willd.) Vatke. Both millet and sorghum strains of S. hermonthica were equally responsive. The response of Striga seeds to thidiazuron increased with conditioning. Early applications of the compound induced some germination, but had adverse effects on the conditioning process. Induction de la germination des graines de Striga par le thidiazuron Le thidiazuron de 0,1 à 10 mg 1−1 a induit de façon conjointe le germination et l'initiation d'haustoria chez Striga asiatica et S. hermonthica, mais n'a pas eu d'effet sur S. gesnerioïdes. Les souches de S. hermonthica liées au millet et au sorgho ont un comportement équivalent. La réponse des graines de Striga au thidiazuron a augmenté par conditionnement préalable. Des applications précoces de produit ont induit quelques germinations, mais ont eu des effets contraires sur Ie processus de conditionnement. Einleitung der Samenkeimung bei Striga‐Arten durch Thidiazuron Mittels Thidiazuron‐Lösungen von 0,1 bis 10 mg 1−1 konnten eine gleichzeitige Keimung und Ausbildung der Haustorien bei Striga asiatica (L.) Kuntze und S. hermonthica (Del.) Benth. herbeigeführt werden, nicht jedoch bei S. gesnerioides (Willd.) Vatke. Der Rispenhirsen‐und der Sorghum‐Typ von S. hermonthica reagierten in gleichem Maße. Konditionierung der Striga‐Samen förderte die Wirkung von Thidiazuron. Frühe Anwendung des Wirkstoffs führte zu einer geringen Keimung, beeinträchtigte jedoch die Konditionierung.
Soil degradation of flumetsulam at different temperatures in the laboratory and field
Authors: LEHMANN R. G. , FONTAINE D. D. , OLBERDING E. L. 
Published: July 2006

Summary: Résumé: ZusammenfassungThe degradation rate of the herbicide flumetsulam was examined in Hoytville clay soil at five temperatures and optimal moisture. Half‐lives were 246 days at 7.5°C, 115 days at 15.0°C, 49 days at 26.1°C, 34 days at 35.9°C, and 27 days at 44.0°C. Construction of an Arrhenius diagram (In k = ‐Ea/RT+In A) allowed the rate constant k to be calculated for any temperature T. When k was inserted into the first order rate equation (c = c0‐kt), the concentration of flumetsulam could be calculated on a monthly basis for any soil.Predictions from this theoretical model were compared with data from three US field locations and found to accurately predict soil residues of flumetsulam under favourable moisture conditions, but not during periods of drought. Degradation dans le sol du flumetsulam à differentes temperatures au laboratoire et en plein champ Le taux de dégradation de l'herbicide flumetsulam a étéétudié dans un sol argileux de Hoytville à 5 temperatures et à l'humidité optimale. Les demi‐vies ont été de 246 jours à 7,5°C, 115 jours à 15°C, 49 jours à 26,1°C, 34 jours à 35,9°C et 27 jours à 44°C. L'établissement d'un diagramme d'Arrhenius (In k= Ea/RT+ln A) a permis de calculer le taux constant k à chaque température. Quand k est inserré dans la première partie de l'équation (c = c0e_kt), la concentration de flumetsulam peut être calculée sur une base mensuelle dans n'importe quel sol. Les prévisions de ce modèle théorique ont été comparérs avec des données de plein champ américaines, et on a noté que ces prévisions étaient correctes sous humidité favorable mais non pendant les périodes de sécheresse. Abbau von Flumetsulam im Boden bei ver‐schiedenen Temperaturen unter Labor‐und Freilandbedingungen Die Abbaurate des Herbizids Flumetsulam wurde bei 5 Temperaturstufen und optimalem Feuchtigkeitsgehalt in einem Hoytville‐Ton‐boden untersucht. Die Halbwertszeiten waren 246 Tage bei 7,5 °C, 115 Tage bei 15,0 °C, 49 Tage bei 26,1 °C, 34 Tage bei 35,9 °C und 27 Tage bei 44,0 °C. Die Anwendung der Ar‐rhenius‐Gleichung ermöglicht die Bestimmung der Abbau‐Konstante k bei jeder Temperatur T. Wenn k in die Abbaugleichung nach Kinetik 1. Ordnung eingefügt wird, können Flumet‐sulam‐Konzentrationen auf einer monatlichen Basis für jeden Boden abgeleitet werden. Vorhersagen nach diesem Modell wurden mil Rückstandswerten von 3 Standorten in den USA verglichen, wobei sich eine gute Übereinstimmung der beobachteten und simulierten Werte unter günstigen Feuchte‐bedingungen ergab, nicht jedoch fur Trocken‐perioden.
Aspects floristico‐agronomiques des mauvaises herbes de la région du Loukkos (Maroc)
Authors: BOUHACHE M. , BOULET C. , CHOUGRANI A. 
Published: July 2006

Résumé: Summary: ZusammenfassungCent vingt champs de céréales, légumineuses et betterave à sucre de la région du Loukkos (Nord Quest du Maroc) ont été prospectés selon un échantillonnage stratifié. Ainsi, 244 espèces de mauvaises herbes appartenant à 37 families botaniques ont été inventoriées. Trois families, Asteraceae, Fabaceae et Poaceae ont fourni 41.8% de l'effectif spécifique. Les dicotylédones (82.3%), les annuelles (82.8%) et l'élément floristique méditerranéan (63.9%) sont prépondérants et caractérisent cette flore. L'étude agronomique nous a permis de distinguer 45 espéces ayant une nuisibilite non négligeable vis à vis des cultures prospectées. Les espèces communes à ces derniàres représentent 51.5, 56.6 et 60.7% de 1'effectif des espèces problématiques relevées pour la betterave à sucre, les céréales et les légumineuses, respectivement. Floristic‐agronomic aspects of weeds in the Loukkos region of Morocco One‐hundred and twenty fields of cereals, legumes and sugar beet were surveyed by stratified sampling in the Loukkos region (north‐west Morocco). In total, 244 weed species belonging to 37 plant families were recorded. Three families, the Asteraceae, Fabaceae and Poaceae accounted for 41.8% of the species. Dicotyledons (82.3%), annuals (82.8%) and the mediterranean floristic element (63.9) were predominant and characterized the weed flora. The agronomic study made it possible to distinguish 45 species causing appreciable problems to the crops surveyed. The weeds common to the three types of crop comprised 51.5%, 56.6% and 60.7% of the problem species in sugar beet, cereals and legumes, respectively. Floristisch‐agronomische Aspekte der Verbreitung von Unkräutern in der Umgebung von Loukkos, Marokko In der Umgebung von Loukkos in Nordwest‐marokko wurde die Unkautflora von 120 Getreide‐Gemüse‐und Zuckerrübenfeldern mit insgesamt 244 Arten aus 37 Familien erfaßt. 41.8 % der Arten gehörten zu den Asteraceae, Fabaceae und Poaceae. Dikotyle (82.3 %), Annuelle (82.8 %) und mediterrane Florenelemente (63.9 %) dominierten und charakterisierten die Flora. Landwirtschaftlich betrachtet konnten 45 Arten fü die untersuchten Kulturen als deutlich problematisch eingruppiert werden. In den 3 Kulturengruppen kamen 56.6, 60.7 bzw. 51.5% der Arten allgemein vor.
A comparison of herbicide bioassays in cell cultures and whole plants
Authors: OLOFSDOTTER M. , OLESEN A. , ANDERSEN S. B. , STREIBIG J. C. 
Published: July 2006

Summary: Résumé: ZusammenfassungDose‐response curves were established for the herbicides chlorsulfuron, metsulfuron‐methyl, ethametsulfuron‐methyl, imazamethabenz and glyphosate. The plant species wereDaucus carota L. and Triticum aestivum L. in cell culture assays, and D. carota L., T. aestivum L., Stellariamedia L., Chenopodium album L. and Avena sativa L., in whole plant assays. Potency ranking of herbicides were similar in the two assays. Low doses of herbicide stimulated growth in both assays, but stimulation was greater in cell cultures. Image processing measured growth in cell cultures and was more sensitive to small differences in responses than manual counts of cell colonies. Dose‐response curves had the same shape in both assays, but cell cultures were more sensitive than were whole plants.Comparaison d'essais biologiques d'herbicides effectués sur cultures de cellules et sur plantes entiéresDes courbes dose‐effet ont étéétablies pour les herbicides metsulfuron‐methyl, ethametsulfuron‐methyl, imazamethabenz et glyphosate. Les espèces végétales étaientDaucus carota L. et Triticum aestivum L.en cultures de cellules, etD. carota L., T. aestivum L., Stellaria media L., Chenopodium album L. et Avena sativa L.dans les essais sur plantes entières. Le classement d'efficacité des herbicides était le meme dans les deux types d'essais. Les faibles doses d'herbicides stimulaient la croissance dans les deux essais mais la stimulation était plus importante en cultures de cellules. La mesure par analyse d'image de la croissance des cultures de cellules était plus sensible à de faibles différences que le comptage manuel des colonies. Les courbes dose‐effet avaient la meme forme dans les deux essais mais les cultures de cellules étaient plus sensibles que les plantes entières.Vergleich von Herbizid‐Biotests mit Zellkulturen und ganzen PflanzenFur die Herbizide Chlorsulfuron, Metsulfuronmethyl, Ethametsulfuron‐methyl, Imazamethabenz und Glyphosat wurden Dosis/Wirkungs‐Kurven erstellt. Die in den Zellkulturen verwendeten Pflanzenarten warenDaucus carota L. und Triticum aestivum L., und bei den Tests mit ganzen Pflanzen D. carota L., T. aestivum L., Stellaria media L., Chenopodium album L. und Avena sativa L.Die Reihenfolge der Herbizide hinsichtlich ihrer Wirksankeit war in beiden Tests ahnlich. Niedrige Herbiziddosen steigerten in beiden Tests das Wachstum, in den Zellkulturen jedoch deutlicher. Bei den Zellkulturen war die Bildanalyse‐Messung fur das Erkennen geringer Unterschiede empfindlicher als das Auszahlen der Zellkolonien. Die Dosis/Wirkungs‐Kurven hatten fur beide Testmethoden den gleichen Verlauf, aber auch hier erwiesen sich die Zellkulturen empfindlicher als die ganzen Pflanzen.