bluuebunny/crossref_metadata_2025_split huggingface dataset:
Translocation of 14C‐glyphosate in johnsongrass (Sorghum halepense L. Pers.) as affected by growth stage and rhizome length
Authors: C.LOLAS P. , COBLE H.D. 
Published: July 2006

Summary: Résumé: ZusammenfassungStudies were conducted in the green house on 14C‐methyllabelled glyphosate translocation in johnsongrass as affected by rhizome length and growth stage. The amount of 14C measured by the liquid scintillation technique in the rhizomes (2‐8%) increased with rhizome length (10, 20 or 30 cm) and tended to increase with growth stage (15‐30 cm tall, 45‐60 cm tall, or at seedhead), but the amount of 14C per g fresh rhizome weight was almost similar in all cases. Of the total amount applied per plant (0·2 μCi) about 1/3 or less remained on the treated leaf area, while another 1/3 was a absorbed into the treated leaves. Autoradiographs showed that the 14C label moved to all plant parts, basipetally and acropetally.Migration du glyphosate 14 C chez le sorgho d'Alep (Sorghum halepense L. Pers.) en relation avec le stage de croissance et la longueur du rhizomeDes recherches ont été effectuées en serru sur la migration du glyphosate marqué au 14C sur le méthyle, chez le sorgho d'Alep, en relation avec la longueur du rhizome et le stade de croissance. La quantité de 14C mesurée par la technique de scintillation liquide dans les rhizomes (2 à 8%) s'est accrue avec la longueur du rhizome (10, 20 ou 30 cm) et elle a eu tendance à augmenter avec le stade de croissance (Hauteur 15‐30 cm, hauteur 45‐60 cm ou épiaison), mais la quantité de 14C par gramme de poids frais de rhizome est restée Presque identique dans tous les cas. Environ 1/3, ou moins, de la quantitéà la surface des feuilles traitées par plante (0,2 μCi), est restéà la surface des feuilles traitées cependant qu'un autre 1/3 a été absorbé dans less feuilles traitées Les autoradiographies ont montré que le 14C marqueur a migré dans toutes les parties de la plante, dans le sens basipète et dans le sens acropète.Translokation von 14C‐Glyphosat in Johnsongras (Sorghum halepense L. Pers.) in Abhängigkeit vom Wachstumsstadium der Pflanzen und der RhizomlängeIm Gewächshaus wurden Versuche über die Translokation von 14C‐Glyphosat in Johnsongras (Sorghum halepense L. Pers.) in Abhängigkeit vom Wachstumsstadium der Pflanzen und der Rhizomlänge durchgeführt. An den Rhizomen stieg der Gehalt von 14C(2–8%), gemessen mit der Flüssig‐Szintillationstechnik, mit zunehmender Rhizomlänge (10, 20 oder 30 cm) an und nahm tendenziell auch mit fortschreitendem Pflanzenwachstum zu (15–30 cm und 45–60 cm Sprosslänge oder nach dem Rispenschieben); jedoch blieb die Menge pro g Rhizomfrischgewicht beinahe konstant. Von der insgesamt ausgebrachten Menge pro Pflanze (0.2 μCi) blieben bis zu 1/3 auf der behandelten Blättern absorbiert wurde. Die Autoradiographie zeigte, dass der 14C markierte Teil in alle Pflanzenteile sowohl basipetal wie auch akropetal transportiert wurde.
Atrazine dissipation in irrigated sorghum cropping in southern New South Wales
Authors: WAIN D. J. S 
Published: July 2006

Summary:Dissipation of atrazine after pre‐emergence application to irrigated grain sorghum was investigated in an experiment on a Birganbigil clay loam at Yanco Agricultural Research Centre in the Murrumbidgee Irrigation Areas of New South Wales. Dissipation followed first‐order kinetics with a half‐life of 70 days. This rate of disappearance did not differ significantly between application rates of 2.5 and 10 kg/ha. Removal of volunteer plant growth with non‐residual chemicals or by cultivation during the winter fallow periods had no significant effect on the levels of atrazine residues in the soil and dissipation rate did not differ significantly between the 2 years of the experiment. A laboratory incubation experiment demonstrated that dissipation of atrazine in Birganbigil soil was more rapid than in three other soils from the Murrumbidgee and Murray Valleys. Dissipation rate and atrazine adsorption were both correlated with the organic carbon content of the soils, which ranged from 1.43% to 0.72%. There was no correlation between either dissipation rate or adsorption and clay content, even though clay contents ranged from 37 to 78%.
Paraquat tolerant Lolium perenne L.: effects of paraquat on germinating seedlings
Authors: FAULKNER J. S. , HARVEY B. M. R. 
Published: July 2006

Summary:A cultivar of Lolium perenne L. (Causeway) selected for tolerance to foliar‐applied paraquat was shown also to be tolerant at seed germination and establishment.When seeds were germinated in paraquat solutions (1, 3, 9, 27 ppm), Causeway was more than ten times as tolerant as a normal cultivar of L. perenne.When germination and survival were studied in a soil which had been sprayed with paraquat (0.0, 0.3, 0.9, 2.7 kg/ha) before sowing, Causeway was nearly three times as tolerant as a normal cultivar. Holcus lanatus L. was about equal to normal L. perenne, but Poa trivialis L. was less tolerant. Phytotoxicity was greater in a 10.5% organic than a 4.8% organic soil.It is concluded that the mechanism of paraquat tolerance operates in the non‐photosynthetic tissues of germinating seedlings as well as in the photosynthetic tissues of older plants, although the degree of tolerance varies according to the mode and stage of application of the herbicide. There might be advantages in using a paraquat tolerant cultivar of L. perenne when direct drilling grass after sward destruction by paraquat.
Weed control in rainfed groundnut (Arachis hypogaea L.) in the Guinea savanna zone of Nigeria
Authors: LAGOKE S. T. O. , CHOUDHARY A. H. , TANKO Y. M. 
Published: July 2006

Summary:Field trials were conducted to evaluate herbicides for weed control in groundnut from 1977 to 1979. The pre‐emergence herbicides used were alachlor and metolachlor, applied alone or mixed with terbutryne. Some treatments were followed either by post‐emergence bentazone or by one supplementary hoe‐weeding. In the southern Guinea savanna zone, where early grass weed control was more important, alachlor or metolachlor at 1.5 kg ha−1 gave adequate weed control and pod yields comparable with that of the hoe‐weeded check. There was no advantage in adding terbutryne, or in supplementary hoeweeding or post‐emergence bentazone application. In the northern Guinea savanna zone, grass and broad‐leaved weeds were equally important. Application of alachlor, metolachlor or mixtures with terbutryne (2:1) at 1.5 kg ha−1 required post‐emergence application of bentazone or supplementary hoe‐weeding for effective weed control and high pod yield. The reduction in pod yield on untreated control plots ranged between 18 and 70% of the best treatment in these trials.
The influence of irradiance and water deficit during fruit development on seed dormancy in Datura ferox L.
Authors: ANCHEZ R. A. , EYHERABIDE G. , de MIGUEL L. 
Published: July 2006

Summary:The effect on seed dormancy of exposing the mother plants to different environmental conditions was studied in Datura ferox. Reducing incident radiation and withholding water to provoke water stress, during the period from fruit set until seed ripening, caused a decrease in the degree of dormancy of the harvested seeds. A significantly smaller amount of the basic fraction inhibitors was found in the seeds with the lesser degree of dormancy. It is suggested that one of the ways in which the environmental conditions to which the mother plants are exposed can influence seed behaviour is by changing the endogenous inhibitor levels
Effects of some herbicides on soil enzyme activities
Authors: And HAZEL A. DAVIES , GREAVES M. P. 
Published: July 2006

Summary:Effects of glyphosate, paraquat, trifluralin and atrazine on activities of dehydrogenase, phosphatase and urease in one soil were measured. Only glyphosate at 21.6 kg/ha was found to inhibit the enzyme activities and generally the results were not statistically significant. Enzyme activity associated with micro‐organisms proliferating in soil supplemented with lucerne meal was similarly not affected by the herbicides. Interpretation of results from enzyme activity measurements in soils treated with herbicides is discussed. It is proposed that effects of natural stress can be used to judge the relative importance of herbicide induced change.
Control of Avena fatua and Fagopyrum tataricum with tank mixtures of linuron or linuron + MCPA and sequential applications of linuron, and post‐emergence A. fatua herbicides
Authors: O'SULLIVAN P. A. 
Published: July 2006

Summary:Linuron (0.21 and 0.28 kg/ha) and linuron + MCPA (0.21+0.56 kg/ha) in a tank mixture with field rates of barban, difenzoquat and flamprop‐methyl reduced the phytotoxicity of these herbicides to Avena fatua. When linuron was applied immediately following or 6 days after the A. fatua herbicides no reduction in phytotoxicity to A. fatua occurred, suggesting that the antagonism may be occurring as a result of physical or chemical incompatability when the herbicides are mixed together. The possibility of obtaining broad‐spectrum weed control with one trip over the field by applying linuron and one of these wild oat herbicides separately but at the same time using a double‐boom, double‐tank system deserves evaluation. When linuron was applied in a tank mixture (0.21 and 0.28 kg/ha), immediately after, or 6 days after diclofop‐methyl (0.70 kg/ha), there was no reduction of A. fatua control, and wheat tolerance to the tank mixture was good. This tank mixture offers potential for control under field conditions of A. fatua and some broad‐leaved weeds in one spray operation. Linuron + MCPA (0.21+0.56 kg/ha) in a tank mixture severely reduced A. fatua control with diclofop‐methyl. No loss of phytotoxicity to Fagopyrum tataricum occurred when the A. fatua herbicides tested were tank mixed with linuron or linuron + MCPA. Lutte contre Avena fatua et Fagopyrum tataricum avec des mélanges extemporanés de linuron ou de linuron + MCPA et des applications successives de linuron et d'herbicides de postlevée actifs contre A. fatua
Comparaison de la germination et de la croissance de biotypes sensibles et résistants aux triazines chez quatre espèces de mauvaises herbes
Authors: GASQUEZ J. , DARMENCY H. , COMPOINT J.P. 
Published: July 2006

Résumé:Par des observations sur la germination dans différentes conditions et sur le développement végétatif en conditions non compétitives, les auteurs comparent des biotypes sensibles et résistants de quatre espèces chez lesquelles on a découvert des populations résistantes: Chenopodium album, Amaranthus retroflexus, Solanum nigrum et Polygonum lapathifolium. Malgré des niveaux de signification différents les résultats indiquent un meilleur développement végétatif des plantes sensibles, Cependant, ces données peuvent être modulées selon les conditions de croissance. Par ailleurs, les valeurs élevées des variances des caractères mesurés traduisent une hétérogénéïté très importante, au moins dans les lots sensibles. En revanche, les semences des plantes résistantes de Polygonum lapathifolium et, dans une moindre mesure, d'Amaranthus retroflexus germent plus facilement aux basses températures. A la lumière de ces données les auteurs discutent les avantages que peuvent conférer ces caractéristiques aux différents lots, mais surtout soulignent la nécessité de considérer chaque espèce séparément et de prendre en compte la nature des génotypes comparés. Enfin, il est difficile, à partir de telles donnés et tant que l'on ignore précisément le déterminisme de la résistance, d'en déduire dans les stations d'origine et en l'absence de traitement, une moindre valeur adaptative des résistants par rapport aux sensibles.
Comportement de substances herbicides dans le sol en fonction de leur structure chimique
Authors: BASTIDE J. , GANTIER J. M. , COSTE C. 
Published: July 2006

Résumé:Des études d'adsorption et de dégradation d'analogues du propyzamide [dichloro‐3,5‐N‐(dimethyl‐1,1 propynyl‐2) benzamide] dans différents sols ont été réalisées. Une bonne corrélation entre adsorption et teneur en matière organique des sols a été trouvée. Cette adsorption est reliée linéairement à un paramètre hydrophobique (coefficient de partage octanol — eau). Par contre la dégradation dans différents sols de ces composés ne montre pas de relation simple avec la nature des sols ou avec la structure chimique des composés. L'importance de ces phénomènes sur les résultats de biotests est aussi analysée.
Control of problem weeds of maize on the Transvaal Highveld (South Africa). I. Tagetes minuta L.
Authors: MALAN C. , VISSER J.H. , GROBBELAAR N. 
Published: July 2006

Summary:A number of herbicides and herbicide mixtures which are being used for the post‐emergence control of weeds in maize on the Transvaal Highveld, have been tested for their efficiency in the control of problem weeds. The evaluation was done under standardized conditions. The influence of the herbicides on the plants was evaluated by using the following bioassay methods: percentage mortality and the percentage dry mass difference between the test plants and the control 10 days after treatment.Recommendations are made as to which herbicides could be used most effectively on problem weeds post‐emergence in maize fields. The developmental stage (age) at which each herbicide is most effective, has been determined.
Selective herbicides for establishing weed‐free grass: The effect of mixtures and sequences of herbicides, including ethofumesate and methabenzthiazuron
Authors: KIRKHAM F. W. , HAGGAR R. J. 
Published: July 2006

SummaryTwo field experiments compared various sequences of ethofumesate, methabenzthiazuron and mecoprop, and mixtures of metamitron, ethofumesate and methabenzthiazuron for their control of Poa annua L. and Stelluria media (L). Vill. during the establishment of autumn‐sown perennial ryegrass (Lolium perenne L.).In experiment 1 pre‐emergence treatments required a second, post‐emergence spraying to give complete control of P. annua. Grass seedlings reappeared in early spring following ethofumesate treatment, but populations built up earlier where methabenzthiazuron had been used. The most successful treatment was ethofumesate at 1.4 kg a.i. ha−1 followed by 0.7 kg a.i, ha−1 in spring. Methabenzthiazuron at 0.8 kg a.i. ha−1 followed by ethofumesate at 0.7 kg a.i. ha−1 in December was also effective. Methabenzthiazuron at 1.6 kg a.i. ha−1 damaged ryegrass but was effective as a secondary treatment at lower doses in spring. Most treatments controlled S. media satisfactorily, but this sometimes increased the yield of P. annua.Metamitron greatly reduced tiller numbers of P. annua in experiment 2, especially when sprayed with methabenzthiazuron. Only treatments which included ethofumesate controlled S. media adequately but there was no advantage in combining this herbicide with any other for controlling P. annua.
Some studies of competition between Avena fatua L. and spring barley I. The influence of A. fatua on yield of barley
Authors: WILSON B. J. , PETERS N. C. B. 
Published: July 2006

Summary A. fauta reduced yields of spring barley in the majority of 51 experiments carried out during 1971 and 1972. Infestations ranging from 8 to 662 seedlings/m2 in the spring resulted in yield reductions varying from nothing to 72%; in 11 experiments these exceeded 1–2 t/ha. Reductions in yield were poorly correlated with numbers of seedlings, panicles or wild oat seeds produced. However, there was a good correlation between yield loss and the dry weight of wild oats at harvest.Growth and competitive effects of wild oats differed between the two years. Grain losses were due mainly to reductions in the numbers of ear bearing barley tillers. The influence and significance of the effect of competition on the size of barley grains is discussed.
Effects of EPTC, fluorodifen and monuron on transpiration and photosynthetic oxygen output in Eupatorium odoratum plants
Authors: ETEJERE E. O. 
Published: July 2006

SummaryThe influence of foliar sprays of EPTC, fluorodifen and monuron on transpiration and photosynthetic oxygen output of Eupatorium odoratum plants is demonstrated. Foliar sprays with 100 ppm EPTC or monuron led to a significant decrease in transpiration for a continuous period of 14 days. Treatment with 100 ppm fluorodifen led to a noticeable increase in transpiration during the first eight days. All three herbicides significantly reduced photosynthetic oxygen output from the Eupaiorium plants. EPTC and monuron however, gave greatest effect. Reduction in transpiration from the plants was due to stomatal closure while reduction in photosynthetic oxygen output was due to both stomatal closure and probably also inhibition of the Hill reaction.
Metabolism of 14C‐buthidazole in corn (Zea mays L.) and redroot pigweed (Amaranthus retroflexus L.)*
Authors: HATZIOS KRITONK , PENNER DONALD 
Published: July 2006

SummaryThe pattern of buthidazole {3‐[5‐(1,1‐dimethyl ethyl)‐1,3,4‐ thiadiazol ‐2‐y1]‐4‐hydroxy‐1‐methyl‐2‐imidazolidinone} metabolism and its potential contribution to crop selectivity were studied in tolerant corn (Zea mays L., ‘Pioneer 3780’) and susceptible redroot pigweed (Amaranthus retroflexus L). Thin‐Layer Chromatographic (TLC) analysis of methanol soluble extracts revealed that both corn and redroot pigweed seedlings metabolized buthidazole in a similar manner but at different rates. At comparable time periods redroot pigweed contained a greater percentage of unmetabolized 14C‐buthidazole than did corn. A major unidentified metabolite with polar properties was formed faster in corn that in redroot pigweed and appeared to be important for the observed crop selectivity of buthidazole. Additional metabolites of buthidazole formed in both species had TLC properties similar to those of the amine, urea, and dihydroxy derivatives of buthidazole.
Experiments with isoproturon for the control of weeds in winter cereal crops
Authors: PONCE R. GONZALEZ , SENAS J. RODRIGUEZ 
Published: July 2006

SummaryIsoproturon controlled Phalaris spp., Lolium spp., Avena sterilis L. and Papaver rhoeas L. in winter cereal crops, the dosages applied being in accordance with the different texture of the soils on which the herbicide was tested in the province of Toledo (Spain).The competitive effects of the weeds, particularly Avena sterilis were ascertained on a range of cereal parameters, not only those influencing yield, but also the grain weight/straw weight ratio.The influence of climatic and edaphic conditions on the efficiency of the herbicide was also investigated.
Environmental conditions and isozyme polymorphism in Chenopodium album L.
Authors: MOUEMAR A. AL , GASQUEZ J. 
Published: July 2006

SummaryElectrophoretic variations within four enzyme systems (α‐esterase, acid phosphatase, malate dehydrogenase and leucine amino peptidase), were studied for various garden and field populations of Chenopodium album. A correlation was found between the degree of polymorphism for the electrophoretic traits and environmental conditions. The amount of phenotypic polymorphism is very high in gardens, intermediate in an untreated and, low in herbicide‐treated fields and nil for a triazine resistant population in a maize (Zea mats L.) monoculture. Furthermore, the tetraploid versus hexaploid ratio is higher within garden populations. Higher variability in garden populations is due, in part, to a high proportion of polymorphic phenotypes, and in part to a low effect of selection pressure in such types of habitat. Although there is a difference between phenotypes of populations from acid soils and those from more basic ones, we cannot be sure that the variation of polymorphism is due only to selection.
Biological activity of dinitramine in soils
Authors: OKAFOR L.I. , SAGAR G.R. , SHORROCKS V. M. 
Published: July 2006

SummaryThe influence of soil organic matter and soil moisture content on the bioactivity of dinitramine was investigated in laboratory and greenhouse experiments. Adsorption increased directly with soil organic matter content and inversely with soil moisture content. Phytotoxicity to soybean (Glycine max (L.) Merr.) was inversely related to soil organic matter content while the toxicity of the herbicide to French bean (Phaseolus vulgaris L.) was directly related to the soil moisture content from 20 to 100% of field capacity. Dinitramine is active in the vapour phase, and volatilization and bioactivity were directly related to soil moisture content and inversely related to soil organic matter content. Variability in the performance of soil incorporated dinitramine in the field seems very likely, depending as it does on soil moisture content and soil organic matter content.
Effect of atrazine and methabenzthiazuron on oxygen evolution and cell growth of Chlorella pyrenoidosa
Authors: GONZALEZ‐MURUA C. , MUNOZ‐RUEDA A. , And F. HERNANDO , SANCHEZ‐DIAZ M. 
Published: July 2006

SummaryCultures of Chlorella pyrenoidosa Pringsheim were grown photoautotrophically in the presence of two concentrations (0·25 and 0·50 μm) of atrazine and methabenzthiazuron. The cell density and chlorophyll content were greatly reduced in presence of both herbicides. These herbicides affected net photsynthesis equally without affecting oxygen uptake. However, cell division was more inhibited by atrazine than by methabenzthiazuron, but chlorophyll content per cell was more inhibited by methabenzthiazuron than by atrazine.
Effect of seed age and cultivation on seedling emergence and seed decline of Avena fatua L. in winter barley
Authors: WILSON B. J. 
Published: July 2006

Summary Avena fatua was sown in a cultivation experiment in the autumn of 3 successive years. For each population seedling emergence and viable seeds in the soil were recorded for 4 years in crops of winter barley in which new seed production was prevented.About half of the seeds sown were recovered after 1 year. In subsequent years viable seeds in the soil declined more rapidly with tine cultivation than with ploughing. After 4 years up to 5% of the original seeds were still viable. One population exhibited greater seed dormancy than the other two populations, due it is thought to higher summer rainfall and the greater availability of moisture during seed maturation.Most seedlings emerged in the autumn and spring, between 12 and 18 months after sowing. A total of 950 seedlings emerged from 12 000 seeds sown; 21% of these seedlings came from new seeds (< 1 year old), 57% from seeds 1–2 years old, 14% from seeds 2–3 years old and 8% from seeds 3–4 years old. Autumn seedlings arose fairly evenly from all age groups while spring seedlings mostly came from the 1–2‐year‐old seeds. With tine cultivation total seedlings over 4 years represented 9–7% and with ploughing 6–2% of the original seeds sown. A. fatua was more persistent than in previous experiments in spring barley, which suggests that control measures would have to be applied for longer in a succession of winter cereals than spring‐sown crops to reduce A. fatua to low populations.
Growth of seedling Achillea millefolium L. (yarrow) in association with pea (Pisum sativum L.)
Authors: KANNANGARA H. W. , FIELD R. J. 
Published: July 2006

SummaryWhen Achillea millefolium L. (yarrow) seedlings were grown in the field in association with a pea (Pisum sativum L.) crop vegetative growth of yarrow was significantly reduced by 6 weeks after emergence. Flowering was totally suppressed while the pure stand of yarrow developed flower clusters at 13 weeks after seedling emergence. Rhizome development occurred at 8 weeks after seedling emergence in the pure stand, but not until 15 weeks when grown with pea.The early suppression of seedling yarrow in a glasshouse experiment was associated with root interference, although by 5 weeks shoot interference by pea plants was important in reducing yarrow growth. The greatest suppression of yarrow occurred when both roots and shoots of the two species were allowed to interfere. Yarrow had low aggressivity against pea when grown in various combinations in a replacement series experiment in the glasshouse.