bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the mechanism of herbicidal action of N‐(Phosphonomethyl) glycine*
Authors: EKANAYAKE A. , WICKREMASINGHE R. L. , LIYANAGE H. D. S. 
Published: July 2006

Summary:Application of N‐(phosphonomethyl) glycine or GLY'PHO‐SATE to couch grass Pancum repens (L) Beauv. resulted in an intitial increase of the total amino acid content in the plant. which reached a maximum on the 8th day following treatment This was most marked in the rhizomes where the value was about three times that of the control plants. The initial increase fell off rapidly with time and on the 15th day after application the total amino acid content of the treated leaf and rhizome samples was less than the controls Resurgence of rhizome activity was noticeable on about the 48th day (viz. 7 weeks after t he Ist application).
Inhibition of seedling growth by wild myrtle (Myrtus communis L.)
Authors: KHOSH‐KHUI M. , BASSIRI A. 
Published: July 2006

Summary:Plants of wild myrtle (Myrtus communis L.) collected at full bloom contained substances inhibitory to the germination and seedling growth of perennial ryegrass. (Lolium perenne L. cv Hollandi)Tissue suspensions had a greater inhibitory activity than water extracts of the plant tissue. Boiling the plant material also increased the inhibitory activity of suspensions and extracts. Flower, and buds, fruit covers and leaves had the greatest inhibitory effect/unit weight ot tissue but inhibitory activity was also present in stems and roots at lower concentrations.The effect of myrtle leaf suspensions on germination of seed of thirteen common garden flowers was also examined: Germination of Petunia. Antirrhinum, Liaum. Cheiranthus and Lathyrus was inhibited completely or substantially depressed. Germination of Zinnia, Tagrtes. Verbena and Dianthus was not much affected, while that of Brllis. Gaillardia. and Viola was affected to an intermediate extent.These results suggest that the possible use of wild myrtle as an evergreen hedge plant needs to be examined further because of possible interference with the growth of nearby lawns and flowers.
Influence of R‐40244 on pigment content of wheat and corn
Authors: DEVLIN R. M. , KISIEL MARIAN J. , KOSTUSIAK ANDRZEJ S. 
Published: July 2006

Summary:Chlorophyll production by wheat (Triticum aestivum L. ‘Mericopa’) and corn (Zea mays L. Merit) was severely curtailed by the experimental herbicide l‐(m‐trifluoromethylphenyl)‐3‐chloro‐4‐chloromethyl‐2‐pyrrolidone (R‐40244). A 96% loss in chlorophyll content was observed in wheat seedlings treated with 320 μmol/1 R‐40244. In corn 320 μmol/1 R‐40244 caused a 40% drop in chlorophyll content. Carotenoid production in both wheat and corn was inhibited by R‐40244, 320 μmol/1 of the herbicide causing a 97% reduction in wheat and a 44% reduction in corn. The inhibition of carotenoid production which, in turn, allows chlorophyll to be photooxidized, may represent the mode of action of R‐40244. Hill reaction activity was not detected for R‐40244.
The significance of noxious weeds on roadsides in agricultural areas of Victoria, Australia
Authors: LANEA D. 
Published: July 2006

Summary:The occurrence of noxious weed species on roadsides and adjacent farmland was studied in ten agricultural areas throughout Victoria. Australia. The presence of noxious weeds in both situations was influenced by the other vegetation present and was reduced by tree cover on roadsides or improved pastures on the farmlands. Most of the noxious species recorded were found both on the roadsides and on farmland. The shrubs (e.g. Acacia armata R. Br., Crataegus monogyna N.J. Jacq., Genista linifolia L. and Lycium ferocisinnum Miers) were more abundant on roadsides, and usually occurred only as hedges on farmland. Hypericum perforatum L. was recorded only on roadsides since this species is now generally controlled in farmland by pasture improvemenl.Because noxious weeds did not appear to invade better managed farmland the significance of their control on roadsides should be reassessed. Where control on roadsides is considered to he necessary, better suppression should be achieved by maintaining good tree and grass cover.
Soil persistence experiments with [14C]2,4‐D in herbicidal mixtures, and field persistence studies with tri‐allate and trifluralin both singly and combined
Authors: SMITH ALLAN E. 
Published: July 2006

Summary:The persistence of [14C]2,4‐D at a rate equivalent to 1 kg/ha was studied in the laboratory on a heavy clay and a sandy loam at 85%of field capacity and 20°C both alone and in the presence of 1 kg/ha dicamba, dichlorprop, difenzoquat, TCA, and 2,4,5‐T. The persistence of 2,4,5‐T was also monitored in both soils under the same conditions in the presence and absence of [14C]2,4‐D. All soils were extracted at weekly intervals using aqueous acidic acetonitrile and analysed for [14C]2,4‐D remainining radiochemical techniques. The extracts containing 2,4.5‐T were additionally analysed gas chromatographically for that herbicide.In each soil type the half‐life of the 2,4‐D was similar regardless of whether applied singly or in combination with the five herbicides tested. Similarly, [14C]2,4‐D did not affect the breakdown of 2,4,5‐T in either soil type.The persistence of tri‐allate (1·5 kg/ha) and trifluralin (0·75 kg/ha) both singly and in combination were compared using small field plots at two locations in Saskatchewan. Applications were made during May of 1977 and 1978 and the plots were sampled and analysed for herbicide(s) remaining after 10 and 20 weeks, respectively. The results indicate that within experimental error the loss of both tri‐allate and trifluralin from the plots treated with the mixture was the same as from plots treated with the individual compounds.
Annual weed competition in wheat crops: the effect of weed density and applied nitrogen
Authors: WELLS G. J. 
Published: July 2006

Summary:Experiments investigating the effect of weed density on the yjeld of a wheat crop at three levels of applied nitrogen were conducted in north‐western Victoria. Australia, during 1970. There were five sites, each infested with a pure stand of one of the following annual broad‐leaved weed species: Lithospermum arvense, Brassica tournifortii. Lamium amplt'xicaule, Amsinckia hispida and Fumaria parviflora. At the three‐leaf stage of crop growth, the weed populations were systematically thinned with a specially developed spray boon) (which is described) to give a range of weed densities in competition) with the crop.The relalionship between dry matter production and population density for all but one weed species was curvilinear, but the degree of curvature was small and competition in the wheat crop was linear for four of the five weed species. There were large differences in the competitive ability of individual weed species and these have been described by regression equations. Applied nitrogen increased wheat yields at all sites but weed competition was not affected.The use of these grain yield‐weed density relationships in predicting crop losses from weed competition is discussed.
Effect of soil water content at the time of application on herbicide content in soil solution extracted in a pressure membrane apparatus
Authors: HANCE R. J. , EMBLING S. J. 
Published: July 2006

Summary:Wettable powder formulations of simazine, metribuzin and linuron and a suspension concentrate of simazine were sprayed on to soil particles which were either at a water content equivalent to pF 2·5 or air dry. Air dry samples were then wetted to pF 2·5 immediately or after 24 h. Soil solutions were removed using a pressure membrane apparatus at intervals up to 96 h after wetting. In each case the concentration in soil solutions expressed after 96 h following application to wet soil, or dry soil wetted immediately, were close to those predicted on the basis of Freundlich adsorption isotherm data obtained in slurry equilibrium conditions. There were, however, some differences after shorter periods.Concentrations were always lower in solutions obtained from air dry soil that was not wetted for 24 h. After 96 h simazine and metribuzin concentrations were about 50% of those obtained following application to wet soil, while that of linuron was about 25%. Differences of this size may be large enough to affect mass transfer phenomena and phytotoxicity. It seems likely that suspension of these herbicides sprayed in formulations on to wet soil dissolved in soil water at least as fast as would be predicted theoretically.
Ultrastructural effects of formulated picloram on leaflets of velvet mesquite and catclaw acacia*
Authors: BLECKMAN C. A. , HULL H. M. , MORTON H. L. 
Published: July 2006

Summary:The effects of picloram formulated with a nonionic surfactant (X‐77) and of the surfactant alone on the ultrastructure of leaf cells of velvet mesquite (Prosopis velutina Woot.) and catclaw [Acacia greggii var. ariznica (Gray) Isely] were examined The surfactant induced temporary protrusions from chloroplasts in both species. A proliferation of rough endoplasmic reticulum (RER) was noted in velvet mesquite within 8h of application of the herbicide and in catclaw with in 27 h. By 72h after treatment. both species exhibited distortions of organelles with more severe symptoms in catclaw. the species more sensitive to the herbicide Leaf abscission occurred subsequently and was more pronounced in catclaw than in mesquitel It is known that RER proliferation is induced by ethylene and that ethylene evolution is stimulated by picloram. The present study suggests that the interaction between these two chemicals was similar in the two plant species studied.
Effect of herbicides on cell membrane permeabUity in Lemna minor
Authors: O'BRIEN MARY C. , PRENDEVILLE G. N. 
Published: July 2006

Summary:Leakage of electrolytes was the criterion used to study the effects of several herbicides on cell membrane permeability in Lemna minor L. Dinoseb. sodium azide, linuron, prometryne and simazine were the most active in increasing cell membrane permeability, followed by oxyfluorfen, amitrole, and 2,4—D. Glyphosate and dalapon were the least active. In all cases, the longer the period elapsed after treatment (i.e. 96 h) the lower was the concentration needed to alter cell membrane permeability. Light was necessary for oxyfluorfen activity. With glyphosate, dalapon and oxyfluorfen, visible injury symptoms were noted after 48–96 h, but no further significant increase in cell membrane permeability occurred as a result.
Selectivity of glyphosate in creeping red fescue and reed canarygrass*
Authors: MAROUIS L. Y. , COMES R.D. , YANG C. P. 
Published: July 2006

Summary:The differential tolerance of resislant creeping red fescue (Fes‐ tuca rubra L, var, rutra) and susceptibie reed canarygrass (Pha‐ laris arundinacea L.) seedlings to glyphosate [N‐(phosphono‐ meihyDglycine) was confirmed under growth chamber condilions. The absorption, transiocation and metabolism of 14C‐glyphosate was examined in both species to determine if differences in these processes could account for the observed selectivity, Creepmg red fescue actually absorbed more glyphosate than did t‐eed canarygrass, and both species rapidly translocated the herbicide throughout their respective tissues. No metabolism of glyphosate was detected in either species. Differential interception and retention of the glyphosate spray can probably be eliminated as possible selectivity mechanisms. The relative tolerance of creeping red fescue to glyphosale appears to be related to its ability lo regenerate roots and shoots from the crown of the plant, but the mechanism of resistance remains obscure.
Studies of Salvia reflexa Hornem. I. Possible competitive mechanisms
Authors: LOVETT J. V. , LYNCH J. A. 
Published: July 2006

Summary:When grown in mixtures with equal numbers of wheat plants Satvia reflexa was found not to be a strong competitor. The height and inflorescence dry weight of wheat was increased by watering the mixtures from above ihe foliage. These effects were accentuated by moisture stress. Aqueous leachatcs oi S. refiexa foliage were found (o inhibit the germination and/or early growth of wheat grown on filter paper in petri dishes and in different soil lypes.
Physiological effects of buthidazole on Zea mays L., Amaratithus retroflexus L., Medicago sativa L. and Agropyron repens(L.) Beauv.*
Authors: HATZIOS KRITON K. , PENNER DONALD 
Published: July 2006

Summary:Buthidazole (3‐[5‐(1,1‐dimethylethyl)‐1,3.4‐thiadiazol‐2‐yl]‐4‐hydroxy‐l‐methyl‐2‐imidazolidinone) at concentrations of 10−6‐10−4M did not affect germination of corn (Zea mays L.,‘Pioneer 3780’), redroot pigweed (Amaranlhus retroflexus L.), alfalfa (Medicago saliva L., ‘Vernal’), and quackgrass (Agropyron repens(L.) Beauv.) seeds. Stressing the seeds obtained from mature corn plants treated either pre‐emergence or pre‐ plant incorporated with buthidazole at several rates by accelerated ageing and cold treatments further indicated that this herbicide did not affect germination. Total photosynthesis and dark respiration of corn plants 12 days after pre‐emergence application and of redroot pigweed, alfalfa, and quackgrass plants after postemergence application of buthidazole at several rates were measured with an infrared CO2 analyser. The results suggested that buthidazole was a rapid inhibitor of photosynthesis of the sensitive redroot pigweed and quackgrass plants, with less effect on corn and alfalfa. Buthidazole did not affect respiration of the examined species except for a transitory increase in corn and alfalfa 12 days after pre‐emergence or 4 h after postemergence treatment with buthidazole at 0.56 or 1.12 and 2.24 kg/ha, respectively. A long‐term inhibition of quackgrass respiration 96 h after treatment with buthidazole at 1.12 and 224 kg/ha was also evident.
The effects of topical applications of glyphosate and aminotriazole on volunteer potatoes (Solanum tuberosum)
Authors: LUTMAN P. J. W. 
Published: July 2006

Summary:Application of small amounts of glyphosate and aminotriazole to the top 2–3 leaves of potato stems killed those stems. Untreated stems attached to the same plant did not die, although they showed symptoms of herbicide damage. Glyphosate caused the death of the apices of the untreated stems, growth of axillary buds and sometimes aerial tuberization. Concentrations of glyphosate between 025 and 8% a.i. and of aminotriazole between 1 and 4% a.i. achieved equally good control of treated stems, although the higher concentrations worked more quickly and generally resulted in more symptoms on the untreated stems. The more stems that were treated on a particular plant, the greater the symptoms on the untreated ones. When all the stems were treated, no healthy tubers were produced; when only some were treated, both healthy and deformed tubers were found at harvest. The effects on the untreated stems are examined in relation to the translocation of glyphosate and the anatomy of the potato plant.
The effect of chlorffenprop‐methyl on 32P uptake, transport and metabolism in Avena fatua L. and Hordeum vulgare L.
Authors: BERGMANNOVÁ EVA , TAIMR L. 
Published: July 2006

Summary:The eflect of chlorfenprop‐methyl on plant weight, root uptake, transport and metabolism of 32P in wild oat and barley plants was examined 4 h. 1, 3 and 9 days after treatment. The fresh weight of treated wild oat plants became significantly less than that of the controls by day 9. There was no significant effect on the weight of barley plants during this period.Uptake of 32P by treated wild oat planus progressively decreased during the experiment and by day 9 was significantly 70% less yhan that in the control: uptake by barley plants showed a significant 30% increase by day 9. Transport of 32P to the shoots followed a similar pattern. In wild oat plants, transport was significantly inhibited at all sampling dales by 44–91%. In barley plants. 32P transport to the shoots tended to be enhanced by day 9 after herbicide treatment.Metabolism of 32P in wild oat plants was affected 4 h after treatment. The content of 32‐P in individual fractions (inorganic, organic, lipidic, and nucleic acid P) was lower in treated plants, especially in the shools. In barley plants. 32P incorporation into the individual fractions was initially inhibited 4 h after treatment, but later corresponded to that found in the control.
Chemical control of Eleusine indica and other weeds in Setaria anceps
Authors: HAWTON D. 
Published: July 2006

Summary:In field experments on the Altherton Tableland. Queensland. Auslralia, methabenzthiazuron used at 1 2 kg ha pre‐emergence was the most effective herbicide for selectively controlling Eleusine indica (L.) Gaertn in seed crops of Setaria anceps Stapf. Bromoxynil. bromoxynil plus MCPA, simazine and terbutryne were either ineffective or phytotoxic to S anceps. A more reliable technique was the use of diuron applied at 2.8 kg ha pre‐emergence when the crop row was physically protected with metal shields at spraying or when activated carbon applied as a slurry in water at 168 kg per sprayed ha was sprayed in a 3 cm wide band over the crop row at sowing Three successive applications of paraquat over a 39 day period prior to sowing the crop were necessary for effective control of E. indica using the ‘stale seed bed’ technique
Inducing a possible state of senescence in developing barley seedlings by applying the α‐chloroacetamide propachlor
Authors: KLEUDGEN HANS KARL 
Published: July 2006

Summary:Propachlor (5, 50, 500 M) applied to the roots of barley (Hordeum vulgare L.) seedlings after 7 and 10 days, respectively, induces decreasing accumulation of fresh matter and dry matter; shoot length and root length are reduced. There was observed higher Hill activity, but lower O2‐evolution per unit dry weight and per seedling as calculated from Hill measurements. In the herbicide treated seedlings lower amounts of chlorophylls and carotenoids were found with decreasing ratios of chlorophylls/carotenoids and higher ratios of xanthophylls/β‐carotene. The ratios of chlorophyll a/benzoquinones decreased with regard to the control data. The accumulation of the single benzoquinones (on a chlorophyll basis), as related to the respective control values, is greater for α‐tocopherol, less for plastoquinone‐9 and even less for α‐tocoquinone. From the data obtained it is assumed that propachlor induces a state of senescence in the chloroplast. Propachlor seems to antagonize the known effects of exogenous indol‐3‐acetic acid. Questions of interaction of herbicide/phytohormone in this connection are discussed.
The effect on yield of mixtures and sequences of herbicides for the control of Alopecurus myosuroides Huds. and broad‐leaved weeds in winter cereals
Authors: WILSON B.J. 
Published: July 2006

Summary:Mixed infestations of Alopecurus m yosuroides Huds. and broad‐leaved weeds in winter cereals were controlled with a commercial formulation of ioxynil + bromoxynil + mecoprop. used in mixtures or as sequences with isoproturon or clofop‐isobutyl. As well as controlling A. myosuroides the mixtures, applied in the autumn, gave good control of Veronica persica Poir., Galium aparine L. Lilhospermum arvense L. and Viola arvensis Murr. weeds which were resistant to isoproturon used alone. A. myosuroides had the major influence on crop yield in three experiments. High infestations of A. myosuroides reduced the broad‐leaved weeds so that crop yields were only slightly improved when all the weeds were controlled compared with the control of A. myosuroides alone. In the remaining experiment. V. persica was very competitive with wheat; additional control of A. myosuroides improved yields considerably.Ioxynil + bromoxynil + mecoprop gave better final control of broad‐leaved weeds when applied in the spring rather than the autumn but the sequence of a spring application following isoproturon or clofop‐isobutyl in the autumn did not improve yields compared with the mixtures applied in the autumn. In all experiments, the highest yields were obtained from controlling both A. myosuroides and broad‐leaved weeds in the autumn, provided that good control of A. myosuroides was obtained.
The biology and control of Lolium rigidum as a weed of wheat
Authors: MONAGHAN N. M. 
Published: July 2006

Summary: Lolium rigidum Gaud. is an important weed of winter crops in some countries with Mediterranean‐type climates. This paper reviews L. rigidum competition in wheat, factors influencing populations of this weed and the effect of control of L. rigidum numbers on wheat yields.
The biology of African feather grass (Pennisetum macrourum Trin.) in Tasmania, I. Seedling establishment
Authors: HARRADINE A. R. 
Published: July 2006

Summary:Seedling establishment of Pennisetum macrourum was studied in a series of glasshouse and field experiments. Maximum germination of 88% occurred at a constant temperature of 30C. In the glasshouse, highest seedling establishment was obtained from seeds buried 1 cm deep; it was less than 25% from seeds sown on the soil surface. Dormancy was induced in seeds buried 8 cm deep but only 6.4% remained viable after 6 months. Few viable seeds of P. macrourum were found in the soil and only one seedling was observed to establish in the field over a 20 month period. Up to 98% of seedlings transplanted into the field established successfully. The results suggest that reproduction by seed would not be a major problem in the control of P. macrourum.
Studies on competition between Setaria anceps and Eleusine indica
Authors: HAWTON D. , DRENNAN D.S.H. 
Published: July 2006

Summary:Experiments were conducted at Kairi. Queensland. Australia on the competitive effects or Eleusine indica (L.) Gaertn. on Setaria anceps Stapf. ev. Nandi. In one experiment S, anceps top dry weights and seed yields were reduced to a similar extent by 20, 40. 80 or 164 (unthinned) E. indica plants/m2. Similarly, the dry matter yields from populations of 20–164 plants/m2 of E. indica did not differ significantly. Varying the density of S. anceps from 6 to 9.3 plants/m2 had little effect on the yield of either species. The mean production of E. indica seed was 1968 kg/ha or approximately 5.3 109 seeds/ha.In two experiments where equal populations of both species were planted at varying times in relation to each other the above ground dry matter yield of S. anceps was not significantly affected when E. indica emerged 2 weeks or later than S. anceps. This was true whether the S. anceps was planted in rows or uniformly throughout the plot. Ina third, similar experiment S. anceps top dry matter was significantly reduced by 21% when the E. indica emerged 2 weeks after the crop.In a time of weeding experiment, removal of E. indica for the first 13 days after planting was sufficient to prevent a significant reduction in S. anceps top dry matter and seed yields. In this experiment the two species were shown to be mutually exclusive.