bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of atomizer, pressure and formulation on the droplet spectra produced by high‐volume sprayers
Authors: COMBELLACK J.H. , MATTHEWS G.A. 
Published: July 2006

Summary:Techniques of high‐volume spraying of weedy plants, have not changed greatly since their introduction in the late 19th century. improvements to the effieiency of the operation have been investigated, and the influence of atomizer type. pressure and formulation on the droplet spectra produced were assessed. The VMD (volume median diameter) decreased log linearly (r2 > 0.98 with all atomizers tested. whilst the volume of the small‐droplet component (< 107 μm) increased linearly (r2) with increasing pressure. A comparison of the droplet spectra produced by three fan and three swirl cone atomizers showed that the fan atomizers gave significantly higher VMD's and lower volumes of small droplets than cone atomizers under comparable operating conditions. The influence of type and concentration of’formulation on the droplet spectra was variable with both the fan and cone atomizers The atomizer and pressure had the greater influence on the droplet spectra. but the effects of formulalion must also be considered if improvements are to be obtained in high‐volume spraying
Soil persistence and distribution of ethofumesate applied to autumn‐sown perennial ryegrass for Poa annua control
Authors: HAGGAR R.J. , PASSMAN A. 
Published: July 2006

Summary:A bioassay technique based on Poa annua growth showed that ethofumesate applied at 2.0 kg/ha in October to a newly‐sown ryegrass (Lolium perenne) sward had a half‐life of just over 8 weeks. After 7 months there was still sufficient herbicide present to cause about a 50% reduction in P. annua growth. The movement of ethofumesate, as measured in soil cores taken 15 months after spraying, was confined mainly to the upper 2 cm of the soil profile. Seeds on the soil surface at spraying were very sensitive to ethofumesate. The implications of the findings for weed control in newly‐sown grass leys are discussed.
In situ potential for rehabilitation of sites dominated by blackberry (Rubus polyanthemos Lindeb.)
Authors: PANETTA F. D. 
Published: July 2006

SummarySoil samples were taken along transects cut through thickets of Rubus polyanthemos at three sites, the seeds were extracted by flotation, and the viability of filled seeds of R. polyanthemos determined by staining with tetrazolium chloride. Exotic annual species were the dominant component of the soil flora at two sites formerly undercultivation and a change in seed bank composition, both in number of individuals and numberof species, was evident from the exterior to the interior of the thickets. This was not observed in a relatively undisturbed native community. The apparent absence of suitable replacement species in the seed bank at all three sites means that they must be introduced if the sites are to be rehabilitated after the thickets are removed. Viable seeds of R. polyanthemos were present in relatively low numbers (mean 179 m−2:), so that loss of viability appears to be fairly rapid.
Effect of glyphosate on the sprouting of Cyperus rotundus L. tubers
Authors: DOLL J.D. , PIEDRAHITA W. 
Published: July 2006

SummaryPost‐emergence applications of glyphosate [N‐(phosphonomethyl)glycine] have been shown not to eradicate purple nutsedge (Cyperus rotundus L.) in the field. It was not known if this was due to failure to control emerged plants or if dormant tubers produced new plants after application. Studies with individual plants were conducted in screenhouse facilities to determine the effects of glyphosate rate, time for translocation, area of foliage treated, and shade on the sprouting ability of tubers attached to treated plants. Rates of 1.5–2.0 kg/ha glyphosate inhibited tuber sprouting; 72 h were required for complete translocation at 1.0 kg/ha whereas 36 h were sufficient at 2.0 kg/ha. Treating less than all of the foliage reduced foliar control and increased tuber sprouting. Shading treated plants reduced control of the foliage but did not affect glyphosate translocation to the tubers. These studies showed that glyphosate kills C. rotundus foliage and the tubers attached to treated plants. Therefore, regrowth after glyphosate application under field conditions is due to dormant tubers which sprout after treatment.
A survey of grass weeds in cereals in central southern England
Authors: FROUD‐WILLIAMS R.J. , CHANCELLOR R.J. 
Published: July 2006

SummaryA survey of grass weeds in cereals in nine areas of central southern England was made in summer 1981 with the primary purpose of determining the importance of Bromus sterilis. A total of 1477 fields of winter wheat, 715 of winter barley and 434 of spring barley were assessed by visually scoring the whole field for grass flower heads. In all, 19 species were found; their levels of infestation were scored. In winter cereals the most frequent species were Avena spp. in 32% of fields. Agropyron repens in 24%, Poa trivialis in 22% and Alopecurus myosuroides in 19%. Bromas sterilis was next most frequent in 9%. In spring barley the two most frequent species were Agropyron repens in 53% of the fields and Avena spp. in 52%. The third most frequent was Alopecurus myosuroides in 1 1%. Bromus sterilis was recorded in 12% of winter wheat and 4% of winter barley crops, but did not occur in spring barley. Of the 206 fields where it was present it occurred throughout the field in only 82 and it was confined to the headlands in the remainder.
Effect of simulated mowing on the translocation of mefluidide in perennial ryegrass (Lolium perenne L.)
Authors: FIELD ROGER J. , WHITFORD A. R. 
Published: July 2006

SummaryYoung plants of perennial ryegrass (Lolium perenne L.) absorbed approximately 50% of an application of the grass growth retardant, mefluidide, while from 6.5 to 21.9% of the applied dose was translocated during a 2‐ or 7‐day period respectively. After the 2‐day period 93.4% of extractable radioactivity was identified as mefluidide. This potentially useful chemical was made unavailable as a result of mowing before or after spraying. Mowing before spraying increased the proportion of cut mature laminae and young laminae, neither of which translocated mefluidide to other plant organs as efficiently as intact, mature leaves. Mowing after spraying removed potentially translocatable mefluidide with the cut mature laminae and reduced mefluidide accumulation in untreated plant parts. While mowing treatments may be aesthetically desirable they probably increase the amount of mefluidide necessary for effective growth retardation.
The dormancy of wild oat seed (Avena fatua L.) from plants grown under various temperature and soil moisture conditions
Authors: PETERS N. C. B. 
Published: July 2006

SummaryWild oat plants of types fA, fB and fC were grown at a constant 15 or 20°C during the period of seed maturation. Seed of the three types differed little in dormancy when grown at 15°C, but at 20°C a larger proportion of seeds of type fA were dormant compared with fB or fC. Overall, dormancy of seed produced at 15 and 20°C was 97 and 63% respectively. Plants of another collection of type fB were grown from seed at 15 or 20°C with or without water stress applied only from the time of panicle emergence. Water stress and high temperature reduced viable seed production. Seed dormancy was tested immediately after collection by planting the seed in soil, and by Petri dish tests. Further Petri dish tests were made after 6 months storage. Seedling emergence in the first autumn from seeds of plants matured without water stress at 15°C was 10% compared with 30% for seeds grown at 20°C. Seeds grown with water stress at 15°C gave 47%, and at 20°C 78% emergence. The majority of emergence from seeds formed at 15°C without water stress occurred in the second spring after burial. Petri dish tests support these findings and suggest that seeds produced in hot dry summers are less dormant than those produced in cool moist ones.
Comportement germinatif des graines d'Amaranthus retroflexus L. recoltées dans les conditions naturelles
Authors: CHADOEUF‐HANNEL RÉGINE , BARRALIS G. 
Published: July 2006

RésuméL'influence de l'époque de levée des plantes porte‐graines et de la période climatique de dissémination sur la dormance des graines d'Amaranthus retroflexus L. prélevées uniquement au niveau de l'inflorescence principale a étéétudiée.Dans les conditions favorables de germination (30 C), les graines récoltées le plus tardivement (mois de novembre) sont, à leur dissémination, les moins donnantes et celles produites très tôt (mois d'août) les plus dormantes. Mais après conservation au sec pendant 60 jours, les graines ont une capacité germinative voisine de 100%, quelle que soit leur origine.Dans les conditions moins favorables de germination (20 C), les graines récoltées sur les plantes qui se sont développées très tard (juinjuillet) germent miex que celles prélevées sur les plantes apparues très tôt (mars‐avril). Ces différences ne sont pas supprimées par la conservation au sec.A la lumière de ces données, les auteurs discutent des interactions des effets entre les facteurs climatiques et l'état physiologique des plantes sur l'aptitude à germer des graines disséminées naturellement.
The production and shedding of Alopecurus myosuroides Huds. seeds in winter cereals crops
Authors: MOSS S. R. 
Published: July 2006

SummarySeed shedding from heads of Alopecurus myosuroides occurred from late June to late August at most locations. Most seeds were shed before winter wheat (Triticum‐aestivum L.) was harvested hut at two winter barley (Hordeum sativum L.) sites, only 50% of seed was shed prior to harvest. The viability of seeds shed at the start and end of the shedding period tended to be lower than that at peak shedding time in late July and early August. There were large differences between sites in the viability of the total amount of seed shed. The results of viability tests based on the presence of full caryopses and germination in pots of sterile soil were similar. Assessments of head numbers and head length were significantly correlated with total seed production. Head length, but not head number assessments, were also significantly correlated with viable seed production.
Grass weed control with herbicide‐treated crop seeds
Authors: DALE J. E. 
Published: July 2006

SummaryFluazifop‐butyl applied in lung oil at rates of 4.4 to 0.5 g a.i. kg−1 soybean seeds was evaluated in the glasshouse for control of Eleuisine indica. Soybean seeds pretreated with herbicide at 4.4 to 2.1 g a.i. kg−1 gave 100% control of E. indica at the highest sowing rate of four seeds per pot and 90 to 80% control when sowed at one seed per pot. Soybeans were not injured by the seed treatment. Cotton seeds pre‐treated with fluazifop at 2.2 g a.i. kg−1 seeds and sown 4 cm apart in a row across a 20 ± 20cm tray of soil containing seeds of Echinochloa crus‐galli produced a weed‐free band 12 cm wide centred on the row of cotton, without injury to cotton. CGA‐82725 (2‐propynyl 2‐(4‐((3, 5‐dichloro‐2‐pyridinyl)oxy)phenoxy) propanoate) at 2–3 g a.i. kg−1 seeds was as effective as 4–4 g fluazifop‐butyl in controlling E. indica. but growth of soybean was retarded. Sethoxydim gave less control than fluazifop butyl at comparable rates and did not injure soybeans.
Interference between velvetleaf (Abutilon theophrasti Medic.) and soybean (Glycine max (L.) Merr.) II. Population dynamics
Authors: DEKKER J. , MEGGITT† W. F. 
Published: July 2006

SummaryTwo field experiments were conducted to determine the effect of changes in Abutilon theophrasti and soybean population numbers through the growing season on soybean dry weight and seed yields. Whether in mixtures or monoculture, the rate of mortality of both species was constant through the growing season. In general, the greater the initial population of either species the greater the rate of mortality through the growing season. Evidence presented supports the hypothesis that A. theophrasti has the adaptive ability of differential mortality at different populations when in mixed stands with soybean and when grown alone and that soybean lacks this ability when mixed with A. theophrasti. This results in smaller, less productive, individual soybean plants.
Basis for antagonism of paraquat phytotoxicity to barley by MCPA dimethylamine*
Authors: O'DONOVAN J.T. , O'SULLIVAN P. A. , CALDWELL C.D. 
Published: July 2006

Summary: Résumé: ZusammenfassungMCPA dimethylamine in a mixture with paraquat reduced the disruptive effects of paraquat on leaf cell membrane integrity in excised barley (Hordeum vulgare L.) leaf segments. Uptake or translocation of 14C‐paraquat over 24 h was not affected when mixed with either MCPA dimethy‐lamine or MCPA mixed butyl ester. In treatments followed by a period of dark, uptake and translocation of 14C‐paraquat was increased compared to treatments followed by a period of light. A mixture of technical paraquat dichloride and technical MCPA dimethylamine in aqueous solution yielded a dark brown precipitate. All of the paraquat ion was present in the supernatant. The absorption spectrum of the supernatant exhibited a strong maximum of 390 nm and a lesser one at 610 nm. The spectrum was close to that produced by aqueous mixtures of paraquat and dimethylamine. In greenhouse studies the phytotoxicity of the supernatant to barley was less than an equivalent amount of paraquat alone and equal to that of the complete paraquat‐MCPA dimethylamine mixture. The presence of dimethylamine alone resulted in an early enhancement of paraquat activity. Spot application of an aqueous suspension of the precipitate to rapeseed (Bras sica campestris L.) resulted in slight epinastic effects but these were considerably less than when an equivalent amount of MCPA acid was applied. The effects of the precipitate were restricted to the treated leaf whereas the effects of MCPA acid were evident throughout the plant. The results suggest a chemical interaction between the dichloride salt of paraquat and the dimethylamine salt of MCPA with the production of two compounds with comparatively less biological activity.
Influence of glyphosate on selected plant processes
Authors: COLE D.J. , CASELEY J.C. , DODGE A. D. 
Published: July 2006

SummaryBiochemical effects of glyphosate have been examined with a variety of plant materials using mostly merislematic or actively growing tissues. The accumulation of chlorophyll was severely retarded and photosynthetic CO2 uptake was inhibited to a lesser extent. These inhibitory effects could not be alleviated by the simultaneous admixture of divalent cations. Glyphosate enhanced the initial substrate‐induction of nitrate reductase, but repressed induction of nitrite reductase, in Ihe latter case correlating with both inhibition of chlorophyll accumulation and CO2 uptake. Inhibition of macromolecule synthesis in single node buds of Agropyron repens(L.) Beauv. was due partly to inhibition of 14C‐precursor uptake. The specific activity of soluble acid phosphatase was enhanced as was the evolution of ethane. Ethylene production was not greatly affected. A marked decrease in microsomal protein was observed but the specific activities of several microsomal enzymes did not decline. Glyphosate had little inhibitory effect on the activity of microsomal ATPases in vitro.
The effect of substituted urea herbicides on the growth of excised tomato roots
Authors: GAUVRIT C. , ROUGétéT E. 
Published: July 2006

SummaryThe action of 23 herbictdal substituted ureas on the growth of excised tomato roots was studied in order to détérmine whether there is a link between the effects of these herbicides on oxidative phosphorylation and on the growth of non‐photosynthetic tissues. Fourteen of these herbicides were inhibitory; chlortoluron and TBU were stimulatory but only in the light. Substituted ureas known to affect plant mitochondria inhibited root growth but to a lesser extent than some which had no action on mitochondria. No clear relationship was found between actions on mitochondria and on root growth. It is suggested that targets other than photosynthesis and oxidative phosphorylation exist for some substituted ureas.
Effect of heat‐treating soil and straw on the subsequent adsorption of chlortoluron and atrazine
Authors: EMBLING S.J. , COTTERILL E.G. , HANCE R.J. 
Published: July 2006

SummaryThe adsorption of chlortoluron and atrazine was measured on a range wheat straw residues that had been heated for periods of 1–5 min at temperatures up to 700°C and and on three soils that had been heated at up to 250°C for 1–5 min.Adsorption of both compounds by straw ash increased with increasing temperature of pretreatment. Atrazine adsorption by any of the soils was not changed markedly chlortoluron absorption was increased with two of the three soils. The results are discussed in terms of the changes in organic functional groups, that are likely to have been produced by the treatment, in relation to the adsorption mechanisms thatmay operate on the two compounds.Adsorption of chlortoluron by mixtures of ash and soil was less than the sum of the adsorption capacities of each component on its own in the cases of two out of three soils.It is concluded that the effect of straw burning on herbicide performance in the field will be variable but could be substantial.Le chauffage du sol et du chaume: influence sur l’adsorption ultérieure de chlortoluron et de l'atrazine
Changes in the incidence of ragwort (Senecio jacobaea L.) infestation of grassland over a 4‐year period in NE Scotland
Authors: FORBES J. C. 
Published: July 2006

SummaryA roadside survey of 4749 fields in eight areas of NE Scotland was conducted annually from 1979 to 1982. The proportion of grass fields infested with ragwort remained steady at 18–19% from 1979 to 1981 but fell to 13·5% in 1982. This fall resulted from fewer fields becoming newly infested and from more fields that had remained in grass ceasing to be infested. The proportion of infested fields remaining in grass that showed a reduction of two or more points on a 0–5 logarithmic scale of ragwort density (a possible indication of the frequency of control measures) was 24·0% in 1979–1980, 21·7% in 1980–1981 and 36·3% in 1981–1982.The incidence of ragwort infestation was consistently higher in some areas than in others and was not related to the proportion of arable crops. The change in incidence of infestation varied greatly between different areas, as did the proportion of infested fields whose score on the 0–5 scale fell by two or more points. In 1979–1980 and 1980–1981 this proportion had to exceed 22% to effect a net decrease in the incidence of infestation in an area, but in 1981–1982 no relationship was evident between these two measures of change. The incidence of infestation in all areas increased with increasing sward age but one area (Moray and Nairn) had a much higher proportion of young grass infested than any of the others. Over 99% of ragwort infestations consisted of Senecio jacobaea, infestations of S. aquatints Huds. being rare.
Weed competition and control in sugarcane
Authors: IBRAHIM A.A.S. 
Published: July 2006

Summary:Losses of about 40% in cane yields due to natural stands of weeds were found in experiments conducted in sugarcane var. Co 527 in the year of planting at Guneid Sugarcane Research Station, Sudan. Weed competition lowered millable stalks per metre row by 32%, stalk height by 24%, stalk thickness by 15% and number of nodes per stalk by 14%. Tillering was the growth phase most affected by weed competition.Cane yields were increased as number of hand weedings increased, but four weedings were not markedly better than three. The average yield (67·04 t ha−1) obtained from four weedings was not significantly (P= 0·05) better than that of three weedings carried out at 3, 6 and 9 weeks after cane planting.Juice analysis components were also affected by weeds and a 15% reduction in sucrose recovery was recorded. Reductions in the other components were only 4–7%.Atrazine and diuron (3·3 kg ha−1), metribuzin (2·4 kg ha−1) and metribuzin (1·3 kg ha−1) in tank mixture with diuron (1·5 kg ha−1) gave excellent residual weed control of the dominant weed species, Ipomoea cordofana Choisy., Brachiaria eruciformis (Sm.) Griseb., Corchorus fascicularis Lam., Ocimum basilicum L. and Dinebra retroflexa (Vahl) Panz., for most of the first growing season. Excellent control of weeds achieved by the herbicide treatments resulted in comparable yields to frequently‐weeded cane. These herbicides were not phytotoxic to sugarcane var. Co 527.
Potential safeners for protecting sorghum (Sorghum bicolor (L.) Moench) against chlorsulfuron, fluazifop‐butyl and sethoxydim*
Authors: HATZIOS KRITON K. 
Published: July 2006

Summary:In greenhouse studies, the efficacy of the herbicide safeners NA(1,8‐naphthalic anhydride), R‐25788 (N,N‐diallyl‐2,2‐dichloroacetamide), cyometrinil and CGA‐92194 [N‐(1,3‐dioxolan‐2‐yl‐methoxy)imino‐benzeneaceto‐nitrile] in protecting grain sorghum (Sorghum bicolor (L.) Moench, cv. ‘Funk G623’) against injury from pre‐emergence or early post‐emergence applications of the herbicides chlorsulfuron, fluazifop‐butyl and sethoxydim was examined. NA as a seed dressing at 0·5 or 1·0% (w/w) was the most effective of the four safeners and offered partial to good protection to sorghum against injury from the lower rates of pre‐emergence applications of all three herbicides. R‐25788 was totally ineffective as a sorghum protectant against fluazifop‐butyl injury but it did antagonize partially the injurious effects of the lower rates of sethoxydim and chlorsulfuron on sorghum. Cyometrinil and CGA‐92194 offered partial protection to sorghum against injury from the lowest rate of all herbicides but their efficacy against higher rates of the three herbicides was very limited. None of the four safeners was effective in protecting grain sorghum against injury from post‐emergence applications of the three herbicides tested.
Etat actuel de l'infestation parSolanum elaeagnifoliumCav. pour les différentes cultures du périmètre du Tadla (Maroc)
Authors: TANJI A. , BOULET C. , HAMMOUMI M. 
Published: July 2006

RésuméLes auteurs présentent l'état actuel de l'infestation des cultures parSolanum elaeagnifoliumCav. dans l'ensemble de la région agricole du Tadla (Maroc Central). En utilisant la méthode des profils écologiques, il apparaît d'une part, que le périmètre des Béni Amir (Nord du Tadla) est beaucoup plus infesté que celui des Béni Moussa (Sud du Tadla) et d'autre part, que les cultures les plus envahies sont celles de printemps (coton, maïs, sésame). Une carte adjointe au texte permet de préciser la répartition de l'espèce au niveau de cette région.
Use of electricity to control bolters in sugar beet (Beta vulgaris L.): a comparison of the electrothermal with chemical and mechanical cutting methods
Authors: DIPROSE M. F. , FLETCHER R. , LONGDEN P. C. , CHAMPION M. J. 
Published: July 2006

SummaryA machine was built to kill reproductive plants (‘bolters’) in sugar beet by high‐voltage electricity. A generating system producing 10, 13 or 17 kV each at 54 kW was connected to a set of guarded electrodes spanning twelve rows, suspended 5–15 cm above the top of a sugar‐beet crop. With 13 kV the system travelling at 5 km h−1 could clear a light‐to‐moderate infestation of bolters at a rate of 2·4 ha h−1 with the tractor's diesel‐fuel consumption at 3·51 ha−1. In 1979, the electrothermal machine, used twice, reduced viable seed returns by 83%; the flail mower used once or twice by 44 and 76–84%; the wire reel mower used once or twice by 45 and 80–87%; and the roller chemical applicator used once by only 13%. Further trials were made in 1981 with an improved electrothermal machine, a rope wick applicator and a flail mower when all gave over 90% control of viable seeds. The electrothermal machine killed between 38 and 41% of bolters compared with 65% for the chemical applicator. The flail mower did not kill any plants.Although possessing many advantages, the electrothermal machines are heavy and more expensive than alternative methods. Development has ceased in the U.K. on electrical weed control but one company in the U.S.A. is selling such equipment.