bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on competition between Macroptilium atropurpureum and Crotalaria goreensis
Authors: HAWTON D. , DRENNAN D.S.H. 
Published: July 2006

Summary:Experiments were conducted at Walkamin, Queensland, Australia on the competitive effects of Crotalaria goreensis Guill. & Perr. on Macroptilium atropurpureum (DC.) Urb. cv. Siratro. In one experiment it was shown that varying C. goreensis densities of 10, 20, 40 and 200 plants/m2 produced successive reductions in M. atropurpureum yields and successive increases in C. goreensis yields. Varying the M. atropurpureum density from 2.3 to 6 plants/m2 did not significantly affect the yield of either species. Two hundred C. goreensis plants/m2 produced approximately 500 106 seeds/ha.In three time of emergence experiments it was shown that the competitive ability of one species relative to the other varied with environmental factors. In one of these experiments with equal numbers of each species C. goreensis lowered M. atropurpureum top dry matter yield only when the former species emerged 2 weeks prior to the M. atropurpureum. When there were many more plants of C. goreensis present, emergence of both species at the same time lowered M. atropurpureum top dry matter yield in one experiment and emergence of C. goreensis 2 weeks after the M. atropurpureum lowered the dry matter yield of the latter species in a third experiment.In a time of weeding experiment it was shown that under the particular environmental and plant density conditions prevailing removal of C. goreensis for 12 days after planting was sufficient to prevent a reduction in M. atropurpureum dry matter. In this experiment it was also shown that under these conditions the two species were not mutually exclusive. In mixtures the C. goreensis provided physical support to the M. atropurpureum, enabling the latter species to intercept more light energy than it could when growing in monoculture.
Etude de la dynamique d'une communaute adventice: I — Evolution de la flore adventice au cours du cycle vegetatif d'une culture
Authors: BARRALISet G. , CHADOEUF R. 
Published: July 2006

Résumé:Un dispositif expérimental a été mis en place pour comparer les effets du travail du sol et du désherbage chimique sur la dynamique d'une communauté adventice (agrophytocénose). Les auteurs décrivent la méthodologie détude et présentent la flore adventice du ce dispositif. Au cours du cycle cultural, la densité des mauvaises herbes passe par un maximum qui se situe en avril dans l'orge d'hiver et en mai dans l'orge de printemps. Le stock en semences viables du sol s'élève à environ 7000 individus par m2 sur 30 cm de profondeur et les levées de mauvaises herbes du semis à la récolte de l'orge n'ont représentê que 6.6% de ce stock. La densité des semences dans le sol est plus élevée entre 0–10 cm et 10–20 cm qu'entre 20–30 cm; leur viabilité est supérieure à 80% pour la majorité des espèces et elle est indépendante de la profondeur d'enfouissement.
Effect of benzoylprop‐ethyl on uptake, transport and metabolism of 32P in Avena fatua L. and Triticum aestivum L.
Authors: BERGMANNOVÁ EVA , TAIMR L. 
Published: July 2006

Summary:The effect of benzoylprop‐ethyl on plant weight, root uptake, transport and metabolism of 32P in wild oat and wheat plants was examined 4 h, 1,3 and 9 days after treatment. The fresh weight of wild oat plants was significantly reduced, due to herbicide action only, by day 9 after treatment. By day 3, shoot weight was decreased while root weight was significantly increased by 47%. No significant changes in plant weight were caused by benzoylprop‐ethyl in wheat plants.Uptake of 32P by treated wild oat plants decreased by 39% compared with the control, by day 9, after an initial increase; uptake of 32P was not significantly influenced in wheat plants. By day 1 transport of 32P to the shoots was significantly reduced in wild oat plants by 34%, whereas in wheat plants it was significantly increased by 35%.Metabolism of 32P was already hampered in wild oat plants 4 h after treatment. The content of 32P was reduced on the first two sampling dates in both the roots and shoots of treated plants in all fractions except in DNA in the shoots. On day 3, this decrease was apparent especially in organic, lipidic and nucleic acid fractions in the shoots; incorporation of 32P into lipidic and RNA fractions was significantly inhibited on day 9 in both the roots and shoots of treated wild oat plants. Wheat plants responded most strongly to benzyoylprop‐ethyl on day 1 after treatment, when 32P incorporation into all fractions except DNA was hampered. Differences between treated and control wheat plants gradually levelled off on days 3 and 9 after treatment.
Effets de divers herbicides sur la croissance mycélienne de souches de Botrytis cinerea pers et de Penicillium expansum Link, sensibles ou résistantes à certains fongicides
Authors: ET P. LEROUX , GREDT M. 
Published: July 2006

Résumé:Sur les 70 herbicides expérimentés. 38 sont faiblement fongitoxiques pour Botrytis cinerea (CI 50, concentration inhibant la vitesse de croissance mycélienne de 50%, égale ou supérieure, à 100 g herbicide/ml milieu nutritif) et parmi ceux‐ci, 10 sont sans effect mme à 1000g/ml. Les produits les plus actifs (CI 50 inférieure à 10 g/ml) sont la chlorthiamide, le dichlobénil, le nitrofène, la propyzamide et des dérivés phénoliques (DNOC, ioxynil, PCP). Dans la plupart des cas Pénicillium expansum est moins sensible que Botrytis cinerea sauf vis à vis de l'endothal, du propanil, du prynachlor et de certaines urées substituées.Les souches résistantes aux fongicides benzimidazoles (carbendazime, thiabendazole.) présentent une sensibilité accrue à certains herbicides carbamates (barbane, chlorbufame.); ceci indique l'existence d'une résistance croisée négative entre ces deux groupes de pesticides antimitotiques. Les souches résistantes aux fongicides imides‐cycliques (iprodione, procymidone, vinchlozoline) et à divers composés aromatiques (biphényle, chloronèbe. dicloran.) peuvent également ltre à des herbicides bipyridiliums, dinitroanilines, diphényléthers, à la chlorthiamide, au dichlobénil et à l'oxadiazon. Cette résistance croisée entre des pesticides à modes d'action biochimique différents reste à expliquer.
Viability of herbicide‐treated seeds of Eupatorium odoratum L.
Authors: ETEJERE E. O. 
Published: July 2006

Summary:The 75–80% viability of Eupatorium odoratum seeds was found to be affected by the temperature of the environment where they were stored. The loss of viability increased with longer periods of storage. Seeds stored under — 10°C or 8°C still retained their viability after 26 months, those stored under 27.5°C or 37°C lost their viability during the same period.There was a gradual loss of viability of herbicide‐treated seeds stored under — 10°C or 8°C. The rate of loss was greater for herbicide‐treated seeds stored under 27.5°C and 37°C and eventually led to the complete loss of viability after a short storage period of up to 13 months. EPTC and molinate had the greatest effects on seed viability.
Einfluß von Diclofop‐methyl auf Wachstum und Entwicklung der Keimlinge von Zea mays L.*
Authors: HOPPE H. H. 
Published: July 2006

Zusammenfassung:Diclofop‐methyl, ein herbtzider Wirkstoff aus der Gruppe der Di(phenoxy)propiosäurederivate, hatte keinen Einfluß, auf die Keimung der Samen von Zea mays. Wurden vorgekeimte Maisoder Bohnenkeimlinge mit dem Wirkstoff behandelt, so kam es beim Mais bereits im Bereich niedriger Wirkstoffkonzentrationen zu einer Hemmung des Keimwurzelwachstums, während die Bohne wesentlich unempfindlicher reagierte. Innerhalb der ersten 24 Std, nach der Herbizidbehandlung war die Wirkung auf dus Längenwachstum der Maiskeimwurzeln reversibel, wenn die Keimlinge auf herbizidfreies Medium übertragen wurden. Höhere Konzentralionen von Diclofop‐methyl (≥10−6 M) leiteten an den Keimwurzeln eine Nekrose ein, die etwa am 2. Tag nach der Behandlung im Bereich der Teilungsund Streckungszonen der Wurzelspitzen sichtbar wurde und sich dann über die Wurzel zum Korn hin ausbreitete‐ Das Herbizid erhöhte das Frisch‐ und Trockengewicht sowie den Trockcnsubstanzgehalt der Keimwurzelspitzen von Zea mays. Diese Effekte konnten auf eine Anreicherung von Zellwandmaterial in den herbizid‐behandelten Wurzelspitzen zurückgeführt werden. In Gegenwart von Hydroxyharnstoff”, einem selektiven Hemmstoff der Zellteilung, war die Wirkung von Diclofopmethyl auf das Längenwachstum der Kcimwurzeln zwar abgeschwächt, jedoch nicht aufgehoben. Aus diesen Ergebnissen kann gefolgert werden, daß Diclofop‐methyl in Prozesse eingreift, die sowohl an der Zellteilung als auch an der Zellstreckung mitwirken.
Emergence patterns of weed seedlings in relation to cultivation and rainfall
Authors: ROBERTS H. A. , POTTER MARGARET E. 
Published: July 2006

Summary:In experiments over 4 years, separate field plots were cultivated once only at 2‐week intervals and the weed seedlings recorded weekly. Soil disturbance resulted in a flush of seedlings of which 90% appeared within 10 weeks after cultivation in early spring and within 3 weeks after cultivation in summer. Weekly emergence then returned to the level prevailing on undisturbed soil. The species composition of the seedling populations varied with the time of year at which the soil was disturbed. In each year there was a spring flush of seedlings, probably associated with rising soil temperature; subsequent flushes were coincident on cultivated and undisturbed soil and were related to the rainfall pattern. In each year there were periods when lack of soil moisture restricted emergence, and this appeared to be the over‐riding factor determining seedling numbers. When cultivations were followed by long dry periods which prevented germination, the numbers of seedlings appearing when rain ultimately fell were no different from those when the soil was disturbed just before the rainfall.
The threat posed by alien weeds in Israel
Authors: DAFNI AMOTS , HELLER DAVID 
Published: July 2006

Summary: Résumé: ZusammenfassungThe alien weed flora of Israel comprises forty species out of a total of seventy‐seven adventive species represented here. Twenty‐nine of them occur in other countries of the Middle East and they probably reached Israel through these countries: the rest me regarded as direct imports from their countries of origin. About nine species have already become major weeds, while the other twenty‐nine species, which are known as noxious weeds from other parts of the world, are in the active process of spreading and reaching this status.Details are given of the ecology, distribution, origin, first record or presence in Israel, agricultural importance and population dynamics for each species.La menace des espèces adventices de manvoises herbes en IsraëlLa flore des espèces adventices de mauvaises herbes en Israël comprend quarante‐deux espéces sur un total de soixcinte‐dixsept espéces de mauvaises herbes représentées ici. Vingt‐neuf d'entre elles apparaissent dans d'autres régions du Moyen Orient et elles ont probablement atteint Israël à travers ces régions, les autres sont considérées comme des importations directes depuis leurs pays d'origine. Neuf espèces environ sont dèjà devenues des mauvaises herbes importantes, cependant que vingt‐neuf autres, qui sont connues comme des espèces nuisibles dans les autres parties du monde, sont en passe de le devenir en Israël et sont en rapide expansion.Des détails sont donnés sur l'éeologic, la distribution l'origine, la première apparition ou la présence en Israël, l'importance agricole et la dynamique de la population pour chacune des espèces.Gefahr durch eingeschleppte Unkräuter in IsraelVon den insgesamt in Israel vorkommenden 77 Adventivpflanzen zählen 40 Arten zu den Unkräutern. Von diesen Adventivpflanzen kommen 29 in anderen Ländern des Nahen Ostens vor und dürften von dort aus nach Israel gekommen sein, die restlichen Arten sind Direktimporte Aus ihren Herunftsländern, Ungefähr 9 Arten sind bereits zu Hauptunkrautern geworden, während die restlichen 29, die als gefährhehe Unkräuter in andercn Teilen der Welt bekannt sind. sich entsprechend ausbreiten und somit künftig auch hierzu gezählt werden müssen.Für jede Art werden nähere Angaben gemacht zu: Ökologie, Verbreitung, Herkunft, erstmaliges Auftreten in Israel, landwirtschaftliche Bedeutung und Populationsdynamik.
The selective control of Poa trivialis by dalapon in perennial ryegrass crops grown for seed
Authors: OSWALD A. K. 
Published: July 2006

Summary: Résumé: ZusammenfassungThe effects of dalapon applied in March and April at doses between 1·7 and 2·8 kg/ha a.e. on Poa trivialis present in crops of perennial ryegrass grown for seed, were investigated. Good control of P. trivialis was achieved at all doses sprayed at both times. Reductions in numbers of inflorescences and yield of seed of perennial ryegrass were however recorded, particularly after applications in March. Differences in the response of perennial ryegrass cultivars were also observed; cultivar S.23 was more susceptible to the herbicide than cultivar S.24. The results also suggest that the variation in response of cultivar S.24 in different experiments within the study may be due to the influence of climatic factors. Lutte sélective contre Poa trivialis avec le dalapon dans des cultures porte‐graines de ray‐grass vivace.Les effets du dalapon, appliqué en mars et en avril à des doses comprises entre 1,7 et 2,8 kg/ha (é.a.) sur Poa trivialis présent dans des cultures porte‐graines de ray‐grass vivace, ont étéétudiés. Une bonne efficacité sur Poa trivialis a été obtenue à toutes les doses appliquées aux deux époques. Toute fois, des réductions du nombre des inflorescences et des rendements en graines du ray‐grass vivace, ont été constatés, particuliérement aprés les applications faites en mars. Des différences entre les réactions des cultivars ont été aussi observées: le cultivar S.23 s'est révélé plus sensible que le cultivar S.24. Les résultats suggèrent que les réactions différentes du cultivar S.24 dans diverses expériences comprises dans ce travail, peuvent également êre dues à l'influence de facteurs climatiques. Selektive Bekämpfung durch Dalapon von Poa trivialis in Deutschem Weidelgras für SamenproduktionDie Wirkung von Dalapon gegen Poa trivialis in Kulturen zur Samengewinnung von Deutschem Weidelgras wurde untersucht. Im März und April wurden Dosierungen zwischen 1,7 und 2,8 kg/ha appliziert. Poa trivialis konnte in alien Dosierungen und an beiden Behandlungszeitpunkten bekämpft werden. Minderungen in der Zahl der Blutenstände und Grassamenerträge von Deutschem Weidelgras wurden jedoeh festgestellt, insbesondere nach Applikation im März. Ebenfalls reagierten die Weidelgrassorten untersehiedlich. Sorte S.23 war gegen das Herbizid empfindlicher als Sorte S.24. Die Resultate deuten auch an, dass die unterschiedliche Reaktion von Sorte S.24 in den Experimenten dieser Untersuchung auf den Einfluss von Klimafaktoren zurückgeführt werden könnte.
Effect of some substituted benzonitriles on photosynthetic activity of spinach and wheat in vivo and in vitro
Authors: SZIGETI ZOLTÁN , SÁRVÁRI ÉVA , BUJTÁS CLAIRE 
Published: July 2006

Summary:The inhibitory effects of nine nitro and/or bromo‐substituted benzonitrile compounds on the photosynthetic electron flow in isolated chloroplasts and on the in vivo CO2 fixation of spinach (Spinacia oteracea L.) and wheat (Triticum aesticum L. cv. Bezoslaya) were investigated.Bromoxynil and 3‐nitro‐5‐hromo‐4‐hydroxy‐bcnzonitrile were the strongest and equally effective inhibitors of Ihe in vivo CO2 fixation of spinach, hut in wheat the nitro‐bromo‐compound is ineffective and 3‐nitro‐benzonitrile is even more inhibitory than bromoxynil. None of the substances affected DCPIPH → methylviologen reduction. In the inhibition of the DCPIP reduction only the 3,5‐disuhstituted 4‐hydroxy‐derivatives were effective. The fact that these compounds affect only the PS II reaction with both H2O and DPC as electron donors suggests a site of inhibition on the reducing side of PS II, between Ihe PS II reaction centre and ihe DCPIP Site. It is suggested that in the inhibition of the DCPIP reduction only steric factors are important and the different electron configuration of the sterieally similar molecules may be involved only in the absorption and translocation processes of the compounds.
Effects of hoeing and rototilling on some aspects of the population dynamics of pure stands of Portulaca oleracea L. (purslane)
Authors: And KIYOKO MIYANISHI , B.CAVERS PAUL 
Published: July 2006

Summary:Two naturally‐established pure stands of Portulaca oleracea L. were used to study the effects of five disturbance schedules (early, midseason, late, repeated and no disturbance) on the development of purslane populations. In one stand disturbance was by rototilling and in the second stand by hoeing. In most disturbed plots, the re‐established stands had densities which were not significantly less than those of the control plots. These stands were composed of plants established by seed germination (seed plants) and by regeneration of roots on severed stems (stem plants) or shoots on root and stem bases (root plants). The composition of these stands depended on the type of disturbance. Undisturbed stands were composed predominantly of seed plants. Disturbed stands had fewer than 55% seed plants. Hoeing resulted in a greater proportion of stem plants and a lower proportion of root plants than rototilling. All disturbances resulted in decreased dry matter yields per unit area. The maximum yields for the controls in the two stands were similar, regardless of differences in density, mean dry weight, size class distribution and time of establishment. Early disturbance resulted in significant decreases in seed capsule production while disturbance late in the season had minimal effects on seed production. The implications for control of purslane in crops are discussed.
Fate of terbutryn in macrophyte‐free and macrophyte‐containing farm ponds
Authors: MUIR D.C.G. , PITZE M. , BLOUW A.P. , LOCKHART W.L. 
Published: July 2006

Summary:Terbutryn (2‐ethylamino‐4‐(tert‐butylamino)‐6‐methylthio‐s‐triazine) was applied in June 1978, to two farm ponds (A and C) near Winnipeg. Canada, to give 100 μg/l water concentrations. The persistence of the herbicide and its degradation products was monitored over a 61‐week period following application. The half‐life of terbutryn m the water column ranged from 3 weeks in Pond C, which contained heavy growths of cattails (Typha sp.) and duckweed (Lemna sp.), to 30 days in Pond A. which was free from aquatic macrophytes, Terbutryn residues m sediment reached a maximum of 1.4 μg/g (dry wt) in Pond A and 0.5 μg/g in C. Maximum concentrations of N‐deethylated terbutryn (2amino‐4‐(tert‐butylamino)‐6‐methylthio‐s‐tria‐zine)(DET) were 14.4 μg/l in Pond A water after 61 weeks and 0.14 μg/g in Pond C sediment after 30 weeks. The maximum concentration of hydroxy‐terbutryn (2‐hydroxy‐4‐ethyl‐amino‐6‐(tert‐butylamino)‐s‐triazine) (HT) observed in pond water was 6.4 μg/l in Pond C after 7 weeks. HT was not detected in sediment (<0.05 μg/g) during the study. After 61 weeks, about 50% of the terbutryn that was added could still be accounted for in Pond A and 35% in Pond C. Terbutryn. DET and HT represented an estimated 71, 28 and 1%, respectively, of total terbutryn remaining in Pond A and 65, 29 and 6%, respectively, of that remaining in Pond C, 61 weeks after application, Terbutryn residues in Typha ranged from 0.3 μg/g (dry wt) in the shoot to 3.3 μg/g in the roots. After 12 weeks, terbutryn residues in plants (Pond C) were estimated to account for 1 to 4% of the herbicide in the pond.
Inhibition of photosynthetic pigments in cucumber cotyledons as a principle for a bioassay with fluridone
Authors: And D.M. DREXLER , FLETCHER R.A. 
Published: July 2006

Summary:The response of etiolated cucumber (Cucumis sativus L. cv. National Pickling) cotyledons to fluridone was investigated in terms of inhibition of photosynthetic pigments, and utility as a bioassay. At a light intensity of 35 W/m2, chlorophyll levels were higher in the controls, than at either 12.9 W/m2, or 75 W/m2. Fluridone inhibition was also more pronounced at that intensity. Significant differences between treatments were established as early as 24 h after exposure to light, when at the lowest fluridone concentration of 0.001 μg/ml, chlorophylls and carotenoids were inhibited 25 and 35% respectively. The system's simplicity and sensitivity suggest its use as a bioassay. It is shown that simple monochromatic absorbances of acetone extracts can satisfactorily estimate chlorophylls and carotenoids. Concentrations of fluridone as minute as 10−9 moles/ litre are easily delected, and the system could feasibly detect even lower levels.
Modification des teneurs en ATP, glucose, fructose et saccharose dans des plantules de concombre (Cucumis sativus) sous l'action de divers herbicides
Authors: DECLEIRE M. , DE CAT W. 
Published: July 2006

Résumé:L'application durant 3 jours de doses létales d'atrazine, de MCPA, de dichlobénil, d'alachlore et de paraquat par voie racinaire et/ou par voie foliaire a permis de démontrer que la phytotoxicité des herbicides n'est pas nécessairement liée à une diminution d'ATP. L'atrazine administrée par voie racinaire provoque dans les feuilles une diminution de 57–88% de glucose et de fructose; de 70–97% de saccharose. Dans les ratines les pertes sont respectivement de 14–60% et 33–96%.L'atrazine par voie foliaire accentue davantage les pertes en glucides. Après traitement au MCPA, le glucose des feuilles croit de 250 a 890%; le fructose de 240 à 630%; le saccharose de 110 a 170%. Dans les racines, le glucose augmente de 150 à 420%; le fructose de 160 à 450% tandis que le saccharose diminue de 20–39%. L'alachlore diminue les sucres réducteurs des feuilles et les augmente dans les racines. Le diehlobénil fait baisser les glucides des feuilles les deux premiers jours et les fait croitre le troisième jour. Les auteurs proposent quelques formules permettant de caractériser la nature des herbicides d'après les rapports des teneurs des constituants analysés.
The use of post‐luminescence decay and fluorescence emission to detect initial herbicide toxicity.
Authors: DEVLIN ROBERT M. , ZBIEC IRENA I. , MURKOWSKI ANTONI J. , KARCZMARCZYK STANISLAW J. 
Published: July 2006

Summary:The influence of pyrazon. norflurazon and glyphosate on post‐luminescence decay and fluorescence emission was studied. Pyrazon and norflurazon significantly increased post‐luminescence decay in wheat (Triticum vulgare L) and cuckoo flower (Cardamine pratensis L.). Pyrazon was much more active than norflurazon m this respect, No influence of’glyphosate on post‐luminescence and the emission ol” fluorescence was observed.Measurements of post‐luminescence decay and fluorescence emission can serve to define some aspects of herbicidal pbyto‐toxicity and provide information on the initial action of those compounds that inhibit photosynthesis.
A note on the biological control of Scurrula cordifolia (Wall.) G. Don by another mistletoe in Sivalik Hills (India)
Authors: PUNDIR Y.P.S. 
Published: July 2006

Summary:Observations made on the hyperparasitism ofViscum loranthiElmer on the parasitic weedScurrula cordifolia(Wall.) G. Don in the Sivalik Hills suggest that the hyperparasite is providing effective biological control of the latter. Moreover, as the hyperparasite appears to attack only mistletoes, it can probably be introduced with safety into other localities whereS. cordifoliais spreading.