bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of ethephon pre‐treatment on the response of Elymus repens to fluazifop‐butyl
Authors: LAWRIE J. , CLAY D. V. 
Published: July 2006

Summary: Résumé: ZusammenfassungGrowth inhibition of pot‐grown Elymus repens (L.) Gould by fluazifop‐butyl was occasionally enhanced by pre‐treatment with ethephon. Studies with 14C‐labelled fluazifop‐butyl showed that ethephon increased the accumulation of 14C in basal buds and proximal parts of the rhizome system. This potential modification in the distribution of fluazifop‐butyl within E. repens rhizomes may have reduced regeneration and recovery of the E. repens, particularly from the basal buds, although there was no increase in the proportion of 14C translocated into the rhizome. Also, ethephon not only activated the sinks in the rhizome but in the foliage of E. repens as well, and could initiate buds without sinks. The effects of ethephon on fluazifop‐butyl phototoxicity were irregular in their occurrence and degree, and possible reasons for this are discussed.Effets depré‐traitements à I'étéphon sur la réponse de Elymus repens au fluazifop‐butylLors d'expériences en pots, des pré‐traitements & 1'étéphon augmentaient occasionnellement 1'inhibition de croissance d'Elymus repens (L.) Gould traité au fluazifop‐butyl. Des etudes avec du fluazifop‐butyl marqué au 14C ont montré que l'éléphon augmentait l'accumulation de 14Cdans les bourgeons de la base et dans les parties proximales des rhizomes. Bien que la proportion de 14C transportée dans le rhizome ne soit pas accrue, cette modification de la distribution du fluazifop‐butyl à l'intérieur des rhizomes d'E. repens pourrait limiter la régénération et la reprise de croissance, en particulier à partir des bourgeons de la base. En outre, l'étéphon activait des puits métaboliques non seulement dans le rhizome mais aussi dans le feuillage d'E. repens et pouvait initier des bourgeons qui ne se comportaient pas comme des puits métaboliques.Tant 1'existence que 1'intensité des effets de 1'étéphon sur la phytotoxicité du fluazifop‐butyl étaient irréguliers et les raisons possibles en sont discutées. Wirkung einer Vorbehandlung mit Ethephon auf die Reaktion von Elymus repens (L.) Gould auf Fluazifop‐butyl In Gewächshausversuchen war die Wuchshem‐mung von Elymus repens durch Fluazifop‐butyl gelegentlich durch eine Vorbehandlung mil Ethephon verstärkt. Untersuchungen mil 14C‐Fluazifop‐butyl ergaben, daß Ethephon die Ak‐kumulation von 14C in basalen Knospen und proximalen Teilen des Rhizoms förderte. Die so mögliche Veränderung der Verteilung von Fluazifop‐butyl in den Quecke‐Rhizomen kann zu der reduzierten Regeneration der Pflanzen geführt haben, vor allem aus den basalen Knospen, obwohl insgesamt keine groBere 14C‐Menge im Rhizom gefunden wurde. Ethephon aktivierte nicht nur die Sinks im Rhizom, son‐dern auch in den oberirdischen Teilen und kon‐nte zur Ausbildung von Knospen ohne Sinks führen. Die Wirkungen des Ethephons auf die herbizide Wirkung des Fluazifop‐butyls war unregelmaßig, und die moglichen Grunde dafiir werden diskutiert.
Impact of root mining by Eteobalea spp. on clonal growth and sexual reproduction of common toadflax, Linaria vulgaris Mill.
Authors: SANER M. A. , MÜLLER‐SCHÄRER H. 
Published: July 2006

Summary: Résumé: ZusammenfassungExperiments with potted plants of the weed Li naria vulgaris Mill. (Scrophulariaceae) were carried out to evaluate the effects of root mining by Eteobalea (syn. Stagmatophora) spp. (Lep. Cos‐mopterigidae). Attacked plants had a shorter flowering season and produced seeds of lower weight. Continuous mining during winter resulted in a doubling of the number of stems in spring, but the total plant biomass remained un affected. This may have been caused by dis rupted apical dominance due to root‐crown damage. The observed effects are expected to complement those of other agents used in the biological control of L. vulgaris in North America. L'incidence du minage des racines par Eteobalea spp. sur la croissance végétative et la reproduction sexuée de la linaire commune Linaria vulgaris Mill.Des expériences en pot sur Linaria vulgaris Mill. (Scrophulariacées) ont été conduites pour évaluer 1'effet du minage des racines par Eteobalea (syn Stagmatophora) spp. (Lep. Cosmo‐pterigidae). La période florale des plantes attaquées était plus courte et les graines pro‐duites avaient un plus faible poids. Un minage continu pendant 1'hiver se traduisait par un dou‐blement du nombre de tiges au printemps mais la biomasse totale de la plante n'était pas affec‐tée. Cela pourrait être dûà 1'arrêt de la dominance apicale par suite de dommages au collet. On attend des effets observés qu'il complètent ceux d'autres agents utilisés dans la lutte biolo‐gique centre L. vulgaris en Amérique du Nord. Einfluß der Befalls der Wurzelbohrer Eteobalea spp. auf Wachstum und sexuelle Fortpflanzung des Gemeinen Leinkrauts (Linaria vulgaris Mill.) Bei Topfversuchen über die Wirkung des Fraßes von Eteobalea (= Stagmatophora) spp. in den Wurzeln von Linaria vulgaris Mill. hatten die be‐fallenen Pflanzen eine kürzere Blühperiode, und die Samen waren leichter. über den Winter an‐hallender Befall führte zur Verdopplung der Sproßdichte, doch die Gesamt‐Biomasse blieb unverändert. Dies könnte auf die Unterbrechung der Apikaldominanz infolge der Schädigung der Wurzelkrone zurückzuführen sein. Die be‐obachteten Wirkungen könnten die anderer biologischer Agentien zur biologischen Bekämpfung von Linaria vulgaris in Nord‐amerika ergänzen.
Mauvaises herbes des céréales de la Chaouia (Maroc). I. Aspect floristique.
Authors: TALEB A. , MAILLET J. 
Published: July 2006

Résumé: Summary: ZusammenfassungAfin de recenser les mauvaises herbes des céréales de la région de la Chaouia (Maroc), 218 relevés floristiques ont été réalisés. 315 espèces adventices appartenant à 45 families botaniques ont ainsi pu être inventoriêes. Avec 87%, les di‐cotylédones prédominent (essentiellement As‐teraceae, Fabaceae, Brassicaceae et Apiaceae). 77% des espéces sont des thérophytes. Le pour‐centage d'éléments méditerranéens est très élevé (64%) et les endémiques, signes d'une caractéi‐sation encore élevée de la flore, atteignent 5%. L'abondance et la fréquence des espèces permet‐tent de déterminer les mauvaises herbes ma‐jeures de cette région. La place relative des géophytes (Convolvulus spp., Arisarum vulgare, Silene vulgaris.) est prépondérante, cependant les messicoles annuelles traditionnelles restent les plus nombreuses grace à 1'absence d'intensi‐fication. Weeds of cereals in Chaonia (Morocco) I. The flora An inventory of weeds of cereals in the Chaonia region of Morocco was made on the basis of 218 botanical surveys. A total of 315 species in 45 families were noted. Dicotyledons (87%) were predominant (mostly Asteraceae, Fabaceae, Brassicaceae and Apiaceae) and 77% of the species were therophytes. There was a high percentage (64%) of Meditteranean species and 5% endemics. The major weeds of the reguri were determined from the abundance and frequency of species. Geophytes (particularly Convolvulus spp., Arisarum vulgare and Silene vulgaris) were preponderant, although the traditional annual cereal weeds were most numerous owing to the lack of agricultural intensification. Unkräuter des Getreides im Gebiet von Chaouia (Marokko) I. Floristische Aspekte Zur Bestimmung der Ackerwildpflanzenflora des Getreides im Gebiet von Chaouia wurden 218 floristische Aufnahmen gemacht. Es wurden 315 Arten aus 45 Familien festgestellt. Dikotyle Arten iiberwiegen mit 87 % (hauptsächlich Asteraceae, Fabaceae, Brassicaceae und Apiaceae). 77 % der Arten sind Therophyten. Der Anteil mediterraner Florenelemente flori‐stisch prägnant vertreten. Aufgrund von Abun‐danz und Frequenz erweist sich fiir diese Region der Anteil der Geophyten (z. B. Convolvulus spp., Arisarum vulgare, Silene vulgaris) an der Verunkrautung als relativ überwiegend, wäh‐rend die Zahl der annuellen Arten unter den extensiven Kulturbedingungen höher liegt.
Seed structure and germination in Discaria toumatou (Rhamnaceae)
Authors: J. A. KEOGH  , BANNISTER P. 
Published: July 2006

Summary: Résumé: Zusammenfassung:Data collected from field trials carried out in different years and environments were used to determine competitive ability and threshold levels of Ammi majus L., Chenopodium album L. and Sinapis arvensis L. The hyperbolic model showed a good fit to the experimental data. The three broadleaf weeds showed low and similar competitive indices (i ranging from 1–08 to 1–75), supporting the hypothesis of a high sunflower competitive ability. The economic threshold was four to six plants m−2 for all three weeds in the case of weed control by hoeing and about six plants m−2 for S. arvensis in the case of a postemergence treatment with imazamethabenz. Limitations and approximations in estimating competitive parameters are pointed out and discussed. Aptitude à la compétition et seuils de nuisibilité de trois mauvaises herbes dicotylédones dans le tournesol Des données recueillies dans des expérimentations au champ conduites dans différents environnements et au cours de différentes années ont été utilisées pour déterminer l'aptitude à la compétition et les seuils de nuisibilité de Ammi majus L., Chenopodium album L. et Sinapis arvensis L. Le modéle hyperbolique fournissait un bon ajustement aux données. Les trois mauvaises herbes avaient des indices de compétition bas et similaires (i de 1,08 à 1,75) ce qui conforte l'hypothèse d'une forte aptitude à la compétition du tournesol.Les seuils économiques étaient 4–6 plantes m−2 pour toutes les mauvaises herbes dans le cas de désherbage mécanique et environ 6 plantes m−2 pour S. arvensis dans le cas de traitement de post‐levée avec l'imazaméthabenz.Les limitations et les approximations dans l'évaluation des paramètres de la compétition sont identifiés et discutés. Konkurrenzkraft und Schadensschwellen von drei dikotylen Unkrautarten in Sonnenblume Anhand von Ergebnissen aus Freilandversuchen in verschiedenen Jahren auf verschiedenen Standorten wurden die Konkurrenzkraft und die Schadensschwellen von Ammi majus L., Chenopodium album L., und Sinapis arvensis L, bestimmt. Die Ergebnisse ließen sich mit einer hyperbolischen Gleichung gut beschreiben. Die Konkurrenzindices i von 1,08 bis 1,75 waren fur alle 3 Arten ahnlich niedrig, worin sich die starke Konkurrenz der Sonnenblume widerspiegelt. Bei mechanischer Unkrautbekampfung lagen die Schadensschwellen fur alle 3 Unkrauter zwischen 4 und 6 Pflanzen m−2, fur Nachauflaufbehandlung mit Imazametabenz fur Sinapis arvenis bei 6 Pflanzen m−2. Grenzen und Annaherung der Bestimmung von Konkurrenzparametern werden eingehend diskutiert.
Phenological patterns in an arable land weed community related to disturbance
Authors: SANS F. X. , MASALLES R. M. 
Published: July 2006

SummaryThe emergence pattern and life cycle of four major species growing in a non–irrigated almond tree grove were analysed in relation to ploughing frequencies and environmental factors. At the community level, the overall emergence pattern was found to be much the same whether or not the soil was disturbed. Nevertheless, soil disturbance in late winter and early spring produced peaks of seedling emergence and brought about an increase in germination. Winter annuals such as Lolium rigidum Gaudin and Diplotaxis erucoides (L.) DC., which emerged in the autumn, started to grow rapidly in winter and spring and were able to pre–empt the environmental resources of the habitat and suppress spring–germinating plants such as Chenopodium album L. and Amaranthus blitoides S. Watson. Late–winter and early–spring disturbances favoured the dominance of summer annuals such as C. album and A. blitoides S. Watson. The different ploughing regimes applied during the first year had effects on plant development and seed production which brought about changes in plant population size during the second year.
Effects of flame weeding on weed species at different developmental stages
Authors: ASCARD J. 
Published: July 2006

SummaryField experiments to investigate the efficacy of flame weeding were conducted in southern Sweden on a variety of natural weed flora at different developmental stages. The susceptibility of different species and stages was compared by modelling the dose–response with logistic models. Weed species with unprotected growing points and thin leaves such as Chenopodium album L., Stellaria media (L.) Vill. and Urtica urens L. were susceptible. When these plants had 0‐4 true leaves, complete kill was achieved at propane doses of 20‐50 kg ha‐1. Species with protected growth points such as Capsella bursapastoris (L.) Medic and Chamomilla suaveolens (P.) Rydb. were tolerant due to regrowth after flaming, and they could be completely killed only in the early stages. Poa annua L. could not be completely killed with a single flame treatment, regardless of developmental stage or propane dose. Plant size had a major influence on the lethal dose requirement. Propane doses of 10‐40 kg ha‐1 were required to achieve 95% control of plant numbers for sensitive species with 0‐4 true leaves, whilst plants with 4‐12 leaves required 40‐150 kg ha‐1. When flaming naturally emerged weeds at early developmental stages, split applications of two half‐dose treatments 1 week apart did not reduce plant numbers as effectively as a single late flame treatment with the same total dose.
The influence of the nematode Meloidogyne incognita on competition between Solanum nigrum and tomato
Authors: PONCE R. GONZALEZ , ZANCADA C. , VERDUGO M. , SALAS L. 
Published: July 2006

SummaryThe effect of Meloidogyne incognita (Kofoid & White) Chitwood, 1949, on the competitive relationship between tomato (Lycopersicon esculentum Mill.) and black nightshade (Solanum nigrum L.) was investigated under glasshouse conditions. Two intraspecific competition treatments were set up for the crop and the weed, and five interspecific treatments where the emergence of S. nigrum plants was progressively delayed in relation to tomato. Nematodes reproduced in all inoculated plants, their multiplication rates being much higher in tomato than in S. nigrum plants. Under nematode‐free conditions, intraspecific competition of tomato was more severe than the interspecific competition shown by the weed S. nigrum. Tomato was as tronger competition with S. nigrum than the weed was with itself. However, when infested by M. incognita, both species displayed a similar competitive ability. Tomato yield losses increased with prolonged weed competition but were greater under nematode‐infested conditions.
Dissipation of metham‐sodium from soil and its effect on the control of Orobanche aegyptiaca
Authors: GOLDWASSER Y. , KLEIFELD Y. , GOLAN S. , BARGUTTI A. , RUBIN B. 
Published: July 2006

SummaryThe effect of metham‐sodium on Orobanche aegyptiaca Pers. was tested in the laboratory and in soil columns. The laboratory experiment was carried out on O. aegyptiaca seeds placed in Petri dishes and germinated with GR24, a synthetic strigol analogue. In soil columns, metham‐sodium was applied by application of the chemical through the irrigation water to three different soils and its dissipation determined in three soil layers by gas chromatography, by a lettuce bio‐assay to check the herbicide's phytotoxicity, and with a flax bioassay to check its effect on O. aegyptiaca. Results of the germination experiments showed an exponential decrease in O. aegyptiaca germination, parallel with the increase of metham‐sodium concentration, with an average effective concentration (EC50) of 18 mg L−1. In a soil column, methylisothiocyanate (MIT, the metham active product) rapidly disappeared from the upper soil level (0–10 cm) within 24 h. Seven days after application only traces of MIT remained in all soil layers in all soils, except for the sandy Rehovot soil that contained low concentrations in the lower soil layer (20–30 cm). Flax bioassay confirmed the chemical analysis, showing that O. aegyptiaca tubercles developed only on plants grown in the upper soil layer of all three soils.
Day and night temperature effects on vegetative growth of Erodium Cicutarium
Authors: BLACKSHAW R. E. , ENTZ T. 
Published: July 2006

SummaryThe vegetative growth response of Erodium cicutarium (L.) ĽHer. ex Ait. to various day:night temperature regimes was studied under controlled environment conditions. Dry matter production was greatest with day temperatures of 18 to 34^C combined with night temperatures of 12 to 18^C. A high night temperature of 24^C was very detrimental, reducing dry matter production to 15 to 25% of that attained at 12^C. The optimum mean daily temperature for growth of E. cicutarium is predicted to be in the range 17 to 20^C. Little growth is predicted at mean daily temperatures below 5^C and above 30^C. Partitioning of biomass in leaves, stems and roots was markedly affected by day and night temperatures. Stem weight ratio was greatest at day temperatures of 18 to 34^C and night temperatures of 18 to 24^C. Maximum leaf weight ratio occurred at day and night temperatures of 10 to 18^C. Root biomass was little affected by day temperatures, but was greatest at a night temperature of 12^C, declining substantially as night temperature increased from 12 to 24^C. Results are discussed in terms of the potential for E. cicutarium to become an increasingly troublesome weed in crops of the Canadian prairies and in terms of possible management strategies for its control.
Réduction de ľutilisation des herbicides dans le maïs‐grain par une application ?herbicides en bandes combinée à des sarclages mécaniques
Authors: LEBLANC M.L. , CLOUTIER D.C. , LEROUX G.D. 
Published: July 2006

Résumé: SummaryCe projet a permis ?évaluer des programmes de désherbage combinant ľapplication ?herbicides en bandes et les sarclages mécaniques comme méthode alternative àľutilisation intensive ?herbicides dans le maïs‐grain (Zea mays L.). Les résultats des travaux menés au Québec en 1991 et 1992 indiquent que ľapplication ?herbicides en bandes (atrazine à 1,0 kg m.a. ha−1+métolachlore à 1,9 kg m.a. ha −1 en post‐levée précoce) sur le rang (40% de la surface totale cultivée) suivie par des sarclages mécaniques sélectifs sur toute la surface procurent des rendements de maïs‐grain équivalents a ceux obtenus là où les herbicides ont été appliqués sur toute la surface cultivée. Il est donc possible de réduire la quantité?herbicides utilisée dans le maïs‐grain sans diminuer son rendement. La répression mécanique des mauvaises herbes a été plus efficace en 1991, qui a été une année sèche comparée à 1992 qui a été froide et pluvieuse. Il ressort de cette étude qu'un traitement combinant une application ?herbicides en bandes et deux sarclages sélectifs sur toute la surface à 2 et 4 semaines après ľémergence du maïs‐grain procure à la fois un désherbage adéquat des adventices et un rendement optimum du maïe. Reduced use of herbicides in corn through herbicide‐banding combined with cultivations The efficacy of various weed management systems utilizing banded applications of herbicides and mechanical cultivations were investigated in order to find alternatives to intensive herbicide use in grain maize (Zea mays L.) production. In experiments conducted in Quebec in 1991 and in 1992, banded applications of atrazine (1.0 kg a.i. ha −1) and metolachlor (1.9 kg a.i. ha−1) on maize rows (40% of field area) combined with post‐emergence cultivations, achieved a similar grain yield to that obtained when herbicides were broadcast over the whole field. In this project, decreasing herbicide was not accompanied with decreasing maize yield. Mechanical weed control was more effective in 1991, a drier year than 1992 which was cool and rainy. A banded application of herbicides followed by cultivations at 2 and 4 weeks after maize emergence provided commercially acceptable weed control and crop yield.
Influence of propaquizafop application rate and time on Sorghum halepense (L.) Pers. control and cotton (Gossypium hirsutum) yield
Authors: HAITAS V. C. , KOTOULA‐SYKA E. , ELEFTHEROHORINOS I. G. 
Published: July 2006

SummaryField experiments were carried out from 1990 through 1992 to study the effect of propaquizafop application rate and application timing of fluazifop, haloxyfop, propaquizafop, quizalofop, and hoeing on Sorghum halepense (L.) Pers. control and seed cotton yield. Control of S. halepense with propaquizafop applied to plants 20–35 cm tall was not affected by rate of application and was similar to that obtained with fluazifop applied at the recommended rate. Cotton yield following all herbicide treatments was greater than that of the weedy control, but lower than that of the weedfree control. S. halepense control with fluazifop, haloxyfop, propaquizafop, and quizalofop applied to plants 20–35 or 35–80 cm tall was greater than that obtained with their application to plants 5–15 or 10–25 cm tall. Ho‐eing, applied once at any S. halepense growth stage, provided less control than any herbicide treatment on the same date. Cotton yield was increased by all herbicide treatments and hoeing compared to that of the weedy control, but the highest yield was obtained after herbicide appli‐cation to S. halepense plants 10–25 cm tall. However, none of the herbicide treatments or hoeing increased cotton yield to the level of the weedfree control.
Absorption, translocation, and fate of propyzamide in witloof chicory (Cichorium intybus L.) and common amaranth (Amaranthus retroflexus L.)
Authors: MERSIE W. 
Published: July 2006

SummaryWitloof chicory (Cichorium intybus L.) is tolerant to propyzamide and common amaranth (Amaranthus retroflexus L.) is sensitive. The absorption, translocation, and metabolism of propyzamide was studied in seedlings of witloof chicory and common amaranth to determine if differences in these processes cause the differential sensitivity. At 24,48, and 72 h after root treatment, there was no difference in the concentration of 14C (g−1 plant dry wt) in com‐mon amaranth and witloof chicory. Approximately 50% of the absorbed 14C was translocated out of the roots to shoots of both species at 24 and 48 h after treatment. After 72 h about 55 and 74% of the absorbed 14C was translocated to shoots of witloof chicory and common amaranth, respectively. Distribution of 14C (g−1 plant dry wt) in plant parts of witloof chicory and common amaranth seedlings was similar. Roots of both species accumulated the highest concentration of total 14C, whereas shoots contained the lowest. Thin layer chromatography revealed that the herbicide was metabolized in neither species 48 h after treatment. No differences were found in absorption, translocation, or metabolism between witloof chicory and common amaranth with regard to propyzamide.
Sulfonylurea resistance in Stellaria media [L.] Vill.
Authors: KUDSK P. , MATHIASSEN S. K. , COTTERMAN J. C. 
Published: July 2006

SummaryA sulfonylurea resistant biotype of common chickweed (Stellaria media L. Vill.) was found in a field treated with chlorsulfuron or metsulfuron for eight consecutive years. In pot experiments the biotype was resistant to postemergence treatments with the following acetolactate synthase (ALS) inhibitors: chlorsulfuron, metsulfuron, tribenuron, triasulfuron, rimsulfuron, sulfometuron, flumetsulam and imazapyr. The level of resistance to chlorsulfuron and sulfometuron was higher than to the other sulfonylurea herbicides. Whereas the level of cross resistance to the triazolopyrimidine herbicide, flumetsulam was comparable to that of metsulfuron, that of imazapyr was significantly lower. In contrast to imazapyr the biotype was not resistant to imazethapyr, an other imidazolinone herbicide. ALS in vitro assays revealed that resistance was due to an ALS enzyme that was less sensitive to ALS inhibiting herbicides. Herbicides with different modes of action were equally effective on the susceptible and resistant biotypes.