bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil persistence studies with [14C]MCPA in combination with other herbicides and pesticides
Authors: SMITH ALLAN E. 
Published: July 2006

SummaryThe persistence of [14C]MCPA at a rate equivalent to 1 kg ha−1 was studied under laboratory conditions in a clay loam, heavy clay and sandy loam at 85% of field capacity moisture and 20±1°C both alone and in the presence of tri‐allate, trifluralin, tri‐allate and trifluralin, malathion, Vitaflow DB, malathion and Vitaflow DB, bromoxynil, bromoxynil and asulam, bromoxynil and difenzoquat, dicamba, dicamba and mecoprop, linuron, MCPB, metribuzin, propanil, TCA, benzoylprop‐ethyl, diclofop‐methyl, and flamprop‐methyl.Except in the soils treated with asulam, the half‐lives of [14C]MCPA in all three soil types were similar, being approximately 13±1 days, thus indicating that none of the other chemicals studied adversely affected the soil degradation of MCPA. In the asulam treated soils, the half‐lives of the MCPA were about 3 days longer than in non‐asulam treated soils; the effect was most marked in the clay loam.
Population regulation of Galinsoga ciliata and G. parviflora
Authors: RAI J.P.N. , TRIPATHI R.S. 
Published: July 2006

SummaryThe population response of the two sympatric annual weeds, Galinsoga ciliata (Raf.) Blake and G. parviflora Cav., which occur abundantly in croplands and early secondary successional communities in the north‐eastern hill region of India was studied in relation to sowing pattern (clump or scattered sowing), population density and soil moisture and texture.In a given sowing pattern, seed germination of both species declined with increase in sowing density and moisture stress. However, sowing of seeds in clumps and an increased proportion of sand in soil enhanced the germination, Fewer weeds died in the population raised from scattered sowing than from clumped distribution. Plants grown at high moisture level matured earlier, and fertility of the survivors was negatively correlated with both density and moisture stress in both species although G. ciliata was less affected.Seed output and dry matter yield per pot of both species increased with population density but the increase was not linearly related to the increase in plant numbers, and density‐induced reduction in seed output was observed at high densities. Galinsoga ciliata appears to tolerate greater density‐stress than G. parviflora. Asubstantial decrease in production of capitula, seeds and dry matter at low moisture level indicates the role played by soil moisture in regulating the population growth of the two weeds. An increased proportion of sand in soil resulted in significantly greater seed production in G. parviflora. Galinsoga ciliata also showed a similar trend although the differences were not statistically significant.
Compatible and antagonistic mixtures of diclofop‐methyl and flamprop‐methyl with herbicides used to control broad‐leaved weeds
Authors: TAYLOR H. F. , LOADER M. P. C. , NORRIS S. J. 
Published: July 2006

SummaryIn glasshouse experiments, the addition of four ‘pyridine herbicides’ (substituted picolinic and pyridyloxyacetic acids) to either diclofop‐methyl or flamprop‐methyl had little effect on wild oat (Avena fatua) control. This contrasts with the serious antagonisms which occur with 2, 4‐D and 2, 3, 6‐TBA. With wild and cultivated oat, l'‐methylheptyl (4‐amino‐3, 5‐dichloro‐6‐fluoro‐2‐pyridyl)oxyacetate (Dowco 433) was completely compatible with diclofop‐methyl and flamprop‐methyl, and there was evidence that its presence improved the control of wild oats. Picloram, 3, 6‐dichloropicolinic acid and triclopyr had only slight effects on phytotoxicity. The control of cleavers (Galium aparine) by picloram, triclopyr and Dowco 433 was not significantly reduced by addition of flamprop‐methyl.Preliminary metabolism studies suggest that picloram does not greatly increase the rate of diclofop detoxification as do 2, 4‐D and 2, 3, 6‐TBA, and the observed compatibility could well be a direct consequence of this.The absence in these greenhouse experiments of serious antagonism between the pyridine herbicides and diclofop‐methyl or flamprop‐methyl suggests that ‘tank mixes’ of these herbicides could be used for the control of both broad‐leaved weeds and wild oats.
The influence of temperature on germination of gorse (Ulex europaeus L.)
Authors: IVENS G. W. 
Published: July 2006

SummaryThe germination of U. europaeus seed was investigated at temperatures between 4 and 40°C on a thermal gradient bar. At constant temperature the germination rate increased linearly with temperature from a minimum near 0°C to an optimum at 18°C and then decreased to a maximum at 26°C. At still higher temperatures seeds became imbibed but only germinated when transferred to cooler conditions. Above 35°C viability was lost. The rate of imbibition prior to germination increased with temperature over the whole range. Germination was not increased either by a light treatment or by potassium nitrate.Germination was not stimulated by a wide range of alternating temperature regimes and at mean temperatures below the optimum the germination rate could be adequately predicted from a formula based on performance at constant temperature. At higher temperatures the observed rates became progressively slower than predicted. Seeds from three different sources were tested, all showing similar relationships between germination rate and temperature but differing in the proportion of hard seed. The proportion was least with seed extracted from the soil, intermediate with a collection from the surface and greatest from pods. The findings are discussed in relation to germination in the field following clearing of gorse thicket.
A root bioassay procedure for the determination of chlorsulfuron, diclofop acid and sethoxydim residues in soils
Authors: HSIAO A. I. , SMITH A. E. 
Published: July 2006

SummaryMeasurement of the root lengths of pre‐ger‐minated oat seedlings (Avena sativa L. var. Sioux) grown in the dark in treated soils was used to assay residues of diclofop acid (2‐[4‐(2,4‐dichloro‐phenoxy)phenoxy]propionate) and sethoxydim (2‐[1‐(ethoxyimino)‐butyl]‐5‐[2‐(ethylthio)‐propy]‐3‐hydroxy‐2‐cyclohexene‐1‐one). Similar measurements involving maize seedlings (Zea Mays L. var. Sunny Vee) were also used to determine residues of the herbicide chlorsulfuron (2‐chloro‐N‐[(4‐methoxy‐6‐methyl‐1,3,5‐triazin‐2‐yl)aminocarbony]benzenesulfonamide) in soils. The procedure appeared to be reproducible with residues of chlorsulfuron, diclofop acid and sethoxydim being detectable at amounts of 0.001, 0.2 and 0.05 μg g−1 respectively.
The persistence and metabolism of isoproturon in soil
Authors: MUUD P.J. , HANCE R.J. , WRIGHT S. J. L. 
Published: July 2006

SummaryThe persistence of isoproturon in soil in pot experiments was the same whether or not the soil contained growing wheat (Triticum aestivum L.) plants, Panllel) work with radioactive isoproturon showed that the breakdown products were the same in the presence and absence of plants. Persistence in the field was reasonably well predicted by a simulation model using the results of laboratory incubation studies and field meteorological data.
Persistence studies with the herbicide sethoxydim in prairie soils
Authors: SMITH ALLAN E. , HSIAO ANDREW I. 
Published: July 2006

SummaryThe persistence of [14C]sethoxydim (2‐[1‐(ethoxyimino)butyl]‐5‐[2‐(ethylthio)propyl]‐3‐hydroxy‐2‐cyclohexene‐1‐one) at the 2 μg g−1 level was studied under laboratory conditions in three soils at 20°C and 85% of their field capacity moistures. Following extraction of the soils with methanol, the herbicide remaining was determined using radiochemical techniques. Loss of radioactivity was more rapid on moist clay loam and sandy loam, where the half‐lives were 12 days, than on heavy clay in which the half‐life was 26 days. Loss of radioactivity from air‐dried soils (15% of field capacity) was negligible with over 94% of the applied activity being recovered after 28 days.The persistence of sethoxydim at a rate of 1 kg ha−1 was investigated under field conditions using small plots at three prairie locations for 3 successive years. Using an oat‐root bioassay procedure, no residues were detected in the 0–10 cm depths of any soils, any year, in September following May treatments.
The fungicide tridemorph as a selective herbicide for the control of Holcus lanatus in ryegrass and of Bonus sterilis in barly
Authors: WATT TRUDY A. 
Published: July 2006

SummaryThe potential of the fungicide tridemorph selectively to control established plants of Holcus lanatus L. in ryegrass (Lolium perenne L) and Bromus sterilis L. in barley (Hordeum vulgare L.) was examined in glasshouse trails. A dose of 4.2 kg ha−1 tridemorph gave selectively between H. lanatus and ryegrass similar to, but more costly than, that which would be provided by 1.2 kg ha−1 asulam. B sterilis was more sensitive to tridemorph than was barley. Two additives, glycerol and the oil‐surfactant mixture ‘PF’ enhanced this selectivity when tridemorph was applied at 2.1 kg ha−1.
Volunteer winter wheat: its effects and control in ryegrass seed production
Authors: WRIGHT D. , HEBBLETHWAITE P. D. 
Published: July 2006

SummaryThe effects of different populations of volunteer winter wheal and their control with ethofumesate and TCA on growth, seed yield and yield components of S.24 perennial ryegrass were investigated in lield experiments in 1978 and 1979.Reductions in ryegrass seed yield due to the presence of wheat depended on the density of wheat and the number and dry weight of ryegrass tillers. The greatest percentage reduction in ryegrass seed yield occurred at high densities of wheat (300 plants m−2) when the number of ear‐bearing tillers and 1000 seed weight of ryegrass were reduced. When Ihe density of wheat was low (80 plants m−2) a smaller reduction in ryegrass seed yield occurred and the number of live wheat plants remaining gradually decreased. Within the range of wheat densities in these experiments (0–300 plants m −2) a 1% loss in ryegrass seed yield occurred for every 10 wheal plants m−2 present in the crop post winter.Both herbicides caused a reduction in number of ryegrass tillers during growth but, except where TCA was applied at 12 kg ha−1 in November, ryegrass seed yields were not significantly reduced (in comparison with a wheat‐free control) and were always greater than those obtained in the presence of wheat where no herbicides had been applied. Levels of volunteer infestation of 300 wheat plants m−2 were controlled with minimum risk of crop damage by applications of 6 kg ha−1 TCA in either October or November, or by application of 1–9 kg ha−1 ethofumesate in November.
Einfluss von Pflanzenschutzmitteln einer Zuckerrüben‐Spritzfolge auf biologische Aktivitäten und auf den Abbau von Chloridazon im Boden. II. Gefäss‐und Laborversuche
Authors: DE FANG FAN , PESTEMER W. , MALKOMES H.‐P. 
Published: July 2006

ZusammenfassungIn Gefäss‐und Laborversuchen wurde das Abbauverhallen und die Pflanzenverfügharkeit von Chloridazon (Pyramin) allein und in Kombination mit anderen Pflanzenschutzmitteln einer Zuckerrüben‐Spritzfolge untersucht sowie deren Einfluss auf bodenbiologische Aktivitäten (Dehydrogenaseaklivität, Strohabbau).Sowohl im Gefässversuch mit und ohne Pflanzenbestand als auch in den Laborversuchen zeigte sich bei allen Behandlungen nach einer kurzen lag‐Phase ein sehr schneller Abbau von Chloridazon, der offensichtlich von den anderen Präparaten unbeeinflusst war. Bei allen Varianten konnten durchschnittlich 10 Tage für eine 50% ige Abnahme der Ausgangskonzentration ermittelt werden. Der mit W asser extrahierbare Anteil des Gesamtrückstands lag in den verschiedenen Kombinationen bis eine Woche nach der Applikation bei durchschnittlich 43% und fiel danach innerhalb der nächsten Woche auf 0% ab. Der Strohabbau wurde durch Pyramin allein nicht verνdert, durch die gesamte Zuckerrüben‐Spritzfolge leicht stimuliert. Im Gefässversuch mit und ohne Pflanzenbestand wurde die Dehydrogenaseaklivilät durch Pyramin allein nicht wesentlich gehemmt, während in der Spritzfolge im unbewachsenen Boden leichte Depressionen auftraten. Im Labor wurde die Enzymaktivität durch Pyramin allein nur wenig, durch die Präparate der Spritzfolge stärker gehemmt.Eine Korrelation zwischen den bodenbiologischen Aktivitäten und dem Abbauverhalten von Chloridazon kann nicht abgeleitet werden.
Influence of pre‐emergence herbicides on root development of Agrostis stolonifera sod*
Authors: BINGHAM S. WAYNE , SCHMIDT RICHARDE 
Published: July 2006

Summary Agrostis stolonifera Huds cv.‘Penncross’ and cv.‘Cohansey’(bentgrass) were maintained as a golf‐course putting green. Five herbicides were evaluated at normal (1 x) and three times normal (3 x) rates for Digitaria sanguinalis (L.) Scop (Crabgrass) control and influence on root development of sod. The herbicides were applied once (April), twice (April and August) and three times (April, June and August) annually. After application of 3 × rates, benfluralin (N‐butyl‐N‐ethyl‐2,6, dinitro‐4‐triflouromethylaniline) and chlorthal‐dimethyl (2,3,5,6‐tetrachloroterephthalic acid dimethyl ester) caused injury on both A. stolonifera cultivars. Shoot injury remained with repeated benfluralin treatments; however, injury was no longer apparent after the first application of chlorthal‐dimethyl. Terbucarb (2,6‐di‐t‐butyl‐p‐tolyl N‐methylcarbamate) completely killed both cultivars during the second year of the study. Bensulide (N‐[2‐(0,0‐di‐isopropyldithiophosphoryl)ethyl]benzene sulphonamide) and siduron (N‐(2‐methylcyclohexyl)‐N‐phenylurea) did not influence shoot growth of either A. stolonifera cultivars. Chlorthaldimethyl, bensulide and siduron allowed excelent sod rooting in both cultivars. The 3 × rate of the three herbicides did affect rooting of ‘Cohansey’ cultivar during the second year of the study, as did the 1 × rate of benfluralin. The benfluralin injury did not persist from one treatment time to the next, even at 3 × rates. Terbucarb restricted root growth for the entire year. Bensulide and siduron provided acceptable D. sanguinalis control and acceptable A. stolonifera tolerance under golf‐course green management and re‐establishment with turf.
EWRS Herbicide‐Soil Working Group: Collaborative experiment on simazine persistence in soil
Authors: WALKER A. , HANCE R. J. , ALLEN J. G. , BRIGGS G. G. , CHEN YUH‐LIN , GAYNOR J. D. , HOGUE E. J. , MALQUORI A. , MOODY K. , MOYER J. R. , PESTEMER W. , RAHMAN A. , SMITH A. E. , STREIBIG J. C. , TORSTENSSON N. T. L. , WIDYANTO L. S. , ZANDVOORT R. 
Published: July 2006

SummaryThe effects of soil temperature and soil moisture content on the rate of simazine degradation were measured in the laboratory in soils from sixteen sites located in several different countries. First‐order half‐lives under standard incubation conditions were significantly correlated with clay content, organic carbon content and soil pH in a multiple linear regression. The temperature dependence of degradation was similar in the different soils whereas the moisture dependence showed considerable variation between soils. Persistence of simazine was also measured in the same soils in the field and at live additional sites. Weather records from the different sites for the periods of the Held experiments were used in conjunction with constants derived from the laboratory data in a computer program to simulate persistence in the field. In general, the model overestimated residues in the field. About half of the calculated residues were within 25% of those observed, an accuracy sufficient for practical purposes, but on several occasions the discrepancies between calculated and observed residues were greater than 50%. Possible reasons for the discrepancies and requirements for further experiments are discussed.
Agronomic effects from the control of Agropyron repens in barley by pre‐harvest application of glyphosate
Authors: SHEPPARD B. W. , RICHARDS M. C. , PASCAL J. A. 
Published: July 2006

SummaryPre‐harvest application of glyphosate in barley at 1·44 and 0·72 kg ha−1 was compared with post‐harvest application at 1·44 kg ha−1 at six sites in south‐east Scotland, three sprayed in 1980 and three in 1981. Both levels of pre‐harvest application gave consistent 95–99% control of A. repens compared with 0–76% control from post‐harvest application. Yields of crops grown in 1981 were significantly increased after all the 1980 pre‐harvest treatments and after one post‐harvest treatment. No significant depressions in grain germination were recorded from the lower rate of pre‐harvest application but one significant depression was recorded from the higher rate. Combine harvesting throughput at a given grain loss level was significantly improved by pre‐harvest application and moisture content of grain at harvest was significantly reduced by up to 2·5%. Wheeling losses from pre‐harvest spraying ranged from 1 to 5%. Crop yield increases in the year after spraying compensated for herbicide and application costs plus any yield losses through tractor wheelings.
Control of Avena fatua L. and Cirsium arvense (L.) Scop. with mixtures of 3,6‐dichloropicolinic acid and four herbicides for control of A. fatua
Authors: O'SULLIVAN P. A. , Kirkland K. J. 
Published: July 2006

SummaryControl of Avena fatua (L.) (wild oat) with diclofop methyl applied at 0·7 kg ha−1 at the two‐leaf stage and difenzoquat at 0·84 kg ha−1 at the four‐leaf stage in wheat (Triticum aestivum L.) under field conditions was good and not affected when either of these herbicides was mixed with 3,6‐dichloropicolinic acid as the monoethanolamine salt at 0·14, 0·20 or 0·30 kg ha−1. In the glasshouse, mixtures containing 3,6‐dichloropicolinic acid at rates as high as 0·6 kg ha−1 also did not affect control of A. fatua. When barban at 0·35 kg ha−1, or flamprop methyl at 0·56 kg ha−1 was mixed with similar rates of 3,6‐dichloropicolinic acid and applied at the two‐leaf and four‐leaf stage of A. fatua respectively, a reduction in control of A. fatua (antagonism) occurred under both field and glasshouse conditions. The herbicides for control of A. fatua did not influence the fresh weight suppression of C. arvense shoots obtained in the glasshouse with 3,6‐dichloropico‐colinic acid at 0·3 kg ha−1. Early tolerance of wheat (cv. Neepawa) was acceptable with all mixtures. Wheat yields with diclofop methyl or difenzoquat alone or in mixture with 3,6‐dichloropicolinic acid were increased over the yields from the A. fatua‐infested control.
Measuring spectral differences in vegetation canopies by a reflectance ratio meter
Authors: HAGGAR R. J. , STENT C. J. , ROSE J. 
Published: July 2006

SummaryA simple, robust and inexpensive hand‐held meter is described which senses the presence of green vegetation against brown soil by measuring the ratio of near infra‐red (0·75 μm) to red (0·65 μm) radiances: ratios are higher for green canopies than for soil, due to strong absorption by chlorophyll of red wavelength and the high near‐infrared reflectance of healthy vegetation. Field tests showed that radiance data were correlated closely with plant density and growth stage. Such spectral assessments provide a rapid, nondestructive method of monitoring changes in green‐leaf biomass. Although only small differences in radiance values were recorded from monocultures of various non‐flowering species there was a positive correlation with content of white clover in five grass/clover swards. In addition to being a research aid, these findings confirm the potential of remote sensing of agricultural targets, e.g. detection of weed patches for herbicide spraying, or gaps in swards for sowing seed.
Effect of ammonium sulphate and related salts on the phytotoxicity of dichlorprop and other herbicides used for broadleaved weed control in cereals
Authors: TURNER D. J. , LOADER M. P. C. 
Published: July 2006

SummaryIn glasshouse experiments, additions of 10–100 g 1−1 ammonium sulphate enhanced the phytotoxicity to broadleaved weeds and cereals of several water‐soluble herbicides applied post‐emergence in 75–300 1 ha−1 with hydraulic nozzles. Studies with dichlorprop potassium salt and chickweed Stellaria media (L.) Vill. examined interactions between ammonium sulphate and environmental, application and formulation factors. Simulated rainfall immediately after spraying greatly reduced dichlorprop activity, whether or not ammonium sulphate was present. However, when there was an interval of 2–24 h between spraying and rainfall, the additive increased phytotoxicity. Surfactants tended to reduce dichlorprop phytotoxicity to Stellaria media, both in the presence and absence of ammonium sulphate. Certain other inorganic salts including sodium sulphate also enhanced phytotoxicity. Applications by rotary atomizer in very low spray volume (15 1 ha−1, 250–280 μm drops) were less effective than conventional 150 1 ha−1 applications. When very low volume application was used, addition of ammonium sulphate or nitrate tended to reduce activity further. In the field, ammonium sulphate significantly increased the effects against weeds of a commercial dichlorprop potassium salt formulation applied conventionally in 200 1 ha−1 spray volume. Neutralized phosphoric acid had a similar effect but a mixture of this additive and ammonium sulphate reduced phytotoxicity. Both additives slightly increased dichlorprop injury to barley.
Variation in ethofumesate tolerance in Lolium species and cultivars
Authors: FAULKNER J. S. 
Published: July 2006

SummaryThe ethofumesate tolerances of seventy cultivars of Lolium perenne L., L. multiflorum Lam. and L. x hybridum Hausskn. were investigated by growing seedlings in a glasshouse in a potting compost treated with a critical level of the herbicide. The incidence of seedling deformity and death varied among cultivars, and was generally higher in diploids than in tetraploids, and in L. perenne than in L. multiflorum. Cv. Palaver was outstandingly tolerant. Eight cultivars were re‐tested in pre‐ and post‐emergence field experiments and relative tolerances were similar to those observed in the glasshouse. At the recommended doses for selective weed control, ethofumesate caused some seedling death in susceptible varieties in the pre‐emergence experiment, and both seedling death and reduced herbage production in the post‐emergence experiment. It is concluded that both varietal genotype and environmental factors contribute to the risk of ethofumesate damage in the field.
Action de l'atrazine, du chlortoluron et du MCPA sur les teneurs en pyruvate, oxalacétate, cétoglutarate, glutamate et glutamine dans les feuilles et les racines de concombre (Cucumis sativus)
Authors: DECLEIRE M. , DE CAT W. 
Published: July 2006

RésuméDes doses létales d'atrazine, de chlortoluron et de MCPA ont été administrées à des plantules de concombre (Cucumis sativus) de 17 jours croissant sur solution nutritive. La composition en acides cétoniques, glutamate et glutamine a été déterminée dans les feuilles et les racines après des délais de 1 à 4 jours.Deux jours après l'application d'herbicides inhibiteurs de photosynthèse, les teneurs en cétoglutarate, oxaloacétate, pyruvate, glutamate et glutamine des feuilles sont respectivement de 11 à 20%; 30 à 54%; 43 à 50%; 101 à 112% et 49 à 65% par rapport aux témoins. Après 4 jours, elles sont de 16 à 22%; 31 à 56%; 26 à 42%; 71 à 75% et 180 à 205%. Dans les racines, le glutamate diminue dans la même proportion que le cétoglutarate tandis que la glutamine augmente les deux premiers jours et diminue la quatrième jour. Le traitement au MCPA ne modifie pas la concentration en cétoglutarate des feuilles mais l'augmente de 300 à 800% dans les racines.L'analyse simultanée du cétoglutarate et du glutamate permet de caractériser la nature du traitement herbicide.