bluuebunny/crossref_metadata_2025_split huggingface dataset:
Broomrape control in faba bean (Vicia faba L.) with glyphosate and imazaquin
Authors: SAUERBORN J. , SAXENA M. C. , MEYER A. 
Published: July 2006

SummaryField studies were carried out to evaluate the efficacy of imazaquin and glyphosate in controlling broomrape (Orobanche crenata Forsk. and O. aegyptiaca Pers.) in faba bean (Vicia faba L.) in Northern Syria. Several rates and times of application of the herbicides were tested. Nearly complete control of broomrape was achieved with both the herbicides when they were sprayed twice (when the broomrape attachments to the faba bean roots were at tubercle stage of develoment and 15 days later) at a rate of application of 80 g a.i. ha−1 for glyphosate and 10 g a.i. ha−1 for imazaquin.However, the yield of faba bean did not increase with these treatments, suggesting that the herbicides at these rates were still causing some physiological disorder in the plant that counteracted the beneficial effect of broomrape control on the performance of faba bean plants.
Agronomic performance of a triazine resistant foxtail millet (Setaria italica (L.) Beauv.)
Authors: DARMENCY H. , PERNES J. 
Published: July 2006

SummaryThe agronomic performance of a foxtail millet line resistant to atrazine, obtained through interspecific hybridization between Setaria viridis and S. italica, was compared to that of the original susceptible cultivar of S. italica. In spite of lower grain yields when both were grown in identical conditions, the use of this resistant material is justified because its yield when weeded with atrazine was similar to that of the susceptible cultivar with handweeding. There were no differences in early season growth rates between these lines at cool temperatures.
Isozymic discrimination of tropical Australian populations of mesquite (Prosopis spp.): implications for biological control
Authors: PANETTA F. D. , CARSTAIRS S. A. 
Published: July 2006

SummaryIsozymic variation was investigated in five Australian populations and six reference collections of mesquite (Prosopis section Algarobia). Within nine enzyme systems, a total of 18 loci were examined in detail. 17 of which were polymorphic. Classification and ordination techniques revealed that two of the Australian populations were referable to P. pallida (syn. P. limensis) and another to a polyploid form of P. juliflora. Although the remaining two Australian populations were closely related, only one showed direct evidence of introgression of genes from P. pallida, and the existence of an additional, undetermined parent species was suggested. Owing to the apparent widespread distribution of P. pallida in northern Australia, it may be expedient to seek potential biological control agents from extra‐Australian populations of either this or other species within series Pallidae. However, little is known regarding the general level of host specificity exhibited by the fauna which attacks species in section Algarobia. The overall degree of similarity of the taxa examined in this survey suggests that useful agents for Australian Prosopis might be obtained from the fauna associated with species from both series Pallidae and series Chilenses of section Algarobia.
Untersuchungen zur Wirtseignung verschiedener geographischer Herkünfte von Ackerunkräutern gegenüber dem Rübenzystenälchen Heterodera schachtii Schmidt
Authors: GLEIßL W. , BACHTHALER G. , HOFFMANN G. M. 
Published: July 2006

ZusammenfassungVerschiedene geographische Herkiinftc innerhalb Bayerns von fiinf Ackcrunkraularlen wurden auf ihre Eignung als Wirtspflanzen des Rubenzysten‐alchens Heterodera schachtii Schmidt untersucht. Dabei forderten die Wurzeldit Tusaie siimtlicher geprufler Herkunlte von Capsella bursa‐pasforis und Stellaria media den Larvenschlupf aus Zys‐ten; Chenopodium album‐. Viola arvensis‐ und Galium aparinc‐Hcrkunflc wirkten neutral. Bei erstgenannten Artcn konnten ini Biotest regel‐maBig Zyslenneubildungen fcslgcstelll werden, wahrend an den Wurzein von Chenopodium album nur vcreinzell. an denen von Viola arrensis und Galium aparine in keinem Fall frische Zysten gebildel wurden. Auch hinsichllieh des Einflus.ses aufdie Populationsdichtc (Pf/Pi‐Wert = Quotient aus Endverseuehung und Ausgangsvcrseuchung) tralen keine Untersehiede auf. Die Wirtseignung einer Unkrautspezies gegeniiber Heterodera achachtli stellt somit, zumindesl innerhalb eines begrenzten geographischen Raumcs, eine artspe‐zifisehe Eigenschafl dar.
Dynamik des Samenspeichers in einigen mediterranen Kulturböden
Authors: BERNHARDT K.‐G. , HURKA H. 
Published: July 2006

ZusammenfassungDie Zusammensetzung der Samenspeicher in Kulturfeldern im Mittelmeerraum hängt von unterschiedlichen Faktoren ab. Zum einen ist es die Bodenart, die aufgrund ihrer Struktur auf den Samenvorrat im Boden einwirkt. Weitaus grösser sind aber die Auswirkungen der anthropogenen Beeinflussung wie mechanische Bodenbearbeilung und chemische Behandlungen. Damit zeigen sich für mediterrane Kulturböden die gleichen Einflüsse auf den Samenspeicher wie im mittel‐europäischen Bereich.
Phenology and seed production of variegated thistle, Silybum marianum (L.) Gaertn., in Australia in relation to mechanical and biological control
Authors: DODD J. 
Published: July 2006

SummaryProduction of viable seeds occurred in immature capitula of Silybum marianum following simulated slashing and mowing. In the slashing treatment, capitula with 20 cm or less of stem attached produced viable seeds if cut off when at least half the florets were open, the proportion of viable seeds ranging from 0·3% in capitula at midanthesis to 12% in those at the end of anthesis. Following mowing, viable seeds were produced in full‐sized buds which were close to anthesis and in capitula at any stage of anthesis at the time of plant cutting, the proportion increasing from 0·1% in capitula at the start of anthesis to 30% in those at the end. Within a capitulum, anthesis usually lasted five days in irrigated plants. Ripe seeds were released about 17 days later. Seed production averaged 190 seeds for the primary capitulum and 114 in others. In a flowering season starting in early November and lasting about two months, individual plants had the potential to produce an average of 55 capitula, representing an output of 6350 seeds per plant, of which 94% were viable. In view of the prolonged flowering season and the large seed output of S. marianum, it is argued that the restricted period of oviposition by the weevil Rhinocyllus conicus and the low density of larvae per capitulum might limit its impact as a biological control agent for this weed in Australia.
Assessment of competition between crops and weeds
Authors: VLEESHOUWERS L. M. , STREIBIG J. C. , SKOVGAARD I. 
Published: July 2006

SummaryA two‐species model was used to summarize results of four experiments with two component mixtures of barley (Hordeum vulgare L.), peas (Pisum sativum L.), Chenopodium album L. and Sinapis alba L. grown in pots in greenhouses. The results, covering a wide range of plant densities both in mixtures and pure stands, showed that the model was not always able to describe the relationship between the yield of a species and the densities of itself and its companion species. The deviations from the model were in all instances greatest for the least competitive species. The model that quantifies competition and niche differentiation appeared to be too general because competition between species was not independent of the wide plant density ranges used here. The results are discussed in relation to possible improvements of the model and an analogy between the principles of assessing crop weed competition and the assessment of the relative potency of herbicides in bioassay studies is put forward.
Pre‐treatment environmental effects on the uptake, translocation, metabolism and performance of fluazifop‐butyl in Elymus repens
Authors: COUPLAND D. 
Published: July 2006

SummaryThe performance of fluazifop‐butyl against Elymus repens (L.) Gould was significantly influenced by the environmental conditions in which the plants had grown prior to treatment as follows: soil moisture deficit (greatest reduction of herbicide performance) > cool temperatures > low light intensity. The level of control under conditions in which none of these factors was reduced (so‐called ‘standard’ conditions) was similar to that observed for‘low light’regime plants. Significant effects of environment on spray retention, foliar uptake and amounts of herbicide translocated to the roots and rhizomes were observed. The lowest rates of herbicide uptake were found with plants grown under cool conditions, the greatest amount of basipetal herbicide translocation being associated with low light intensities. Rates of herbicide de‐esterification were much lower in plants grown under low light intensities, cool temperatures, or soil moisture deficits than in those plants grown under the ‘standard’ conditions. This result was confirmed by studies of herbicide deesterification using cell‐free leaf homogenates.
Effets competiteurs d'Avena fatua L. sur le blé comme bases d'une lutte efficace contre les adventices
Authors: WIMSCHNEIDER W. , BACHTHALER G. , FISCHBECK G. 
Published: July 2006

Zusammenfassung:Die von 1975 bis 1979 durchgefuhrten Gefafiver‐suche zum Konkurrenzverhalten zwischen Avena fatua L. (Flug‐Hafer) und zwei Sommerweizen‐sorten ergaben folgende Wirkungen auf den Kornertrag: Im Wettbewerb um die Nahrstoffe nahm die Konkurrenz des FIug‐Hafers mil hoheren Dungungsgaben überproportional zu (Anstieg des Minderertrages von 13 auf 23%). Temporare Trockenheit steigerte die Konkur‐renzwirkung von Avena fatua. Die Besatzdichte von 4 Avena‐fatua‐ und 16 Weizenpflanzen/ Gefa'B bewirkte einen Ertragsrückgang bei Wei‐zen um 9% und 8 Avena‐fatua‐PRanzen/GefaB einen solchen von 14%. Der EiweiBgehalt im Weizenkorn wurde um durchschnittlich 5,5% gemindert. Lichtmessungen ergaben je nach Zeit‐raum eine Reduktion der fur den Weizen nutz‐baren Strahlung bei hoher Flug‐Hafer‐Dichte um 30 bis 35%. Der dadurch bedingte Ertragsverlust betrug im vierjahrigen Durchschnitt 19%. Sortenunterschiede traten nur bei Lichtkonkur‐renz auf. Die Wurzelkonkurrenz beeinfluBte vor‐rangig den Strohertrag, die Lichtkonkurrenz hingegen verstarkt den Kornertrag. Der Zeitfak‐tor wirkte sich vor allem bei hoher Düngung und bei hohem Besatz mil Avena fatua aus. Ein Entwicklungsvorsprung des Flug‐Hafers von 5 Wochen brachte einen Minderertrag des Weizens von 45% gegenüber gleichzeitiger Saat. Aus den Ergebnissen lassen sich pflanzenbauliche Konse‐quenzen bezüglich der Nahrstoffversorgung, der Saatzeit und des Bekampfungstermins ableiten.
Distribution of 14C‐glyphosate in legumes parasitised by Orobanche crenata. Répartition du glyphosate 14C dans des légumes parasités par Orobanche crenata
Authors: ARJONA‐BERRAL A. , MESA‐GARCIA J. , GARCIA‐TORRES L. 
Published: July 2006

Summary:Absorption and translocation of 14C‐glyphosate was evaluated under controlled conditions in peas (Pisum sativum L.) and broad beans (Vicia faba L.) parasitised or not by crenate broomrape Orobanche crenata Forsk.). Absorption increased with time up to 12 days after treatment, and reached about 50% of the 14C‐glyphosate applied. Three days after treatment 70–85% of the total herbicide absorbed had been translocated out of the treated leaflet. There was no consistent differ ence in absorption and translocation between infected and non‐infected plants 12 days after treatment. The 14C‐glyphosate concentration in the root system increased with time in broad beans. In peas it remained more or less constant from 3 days after treatment. Generally, pods were stronger sinks for glyphosate than other parts of the plant. Herbicide accumulation in broomrape increased with its growth stage, and the parasite was a much stronger sink for glyphosate than the legume root system.
Wirksamkeit verschiedener Herbizidbehandlungen auf Equisetum arvense L. in Gerste und Mais in Quebec, Kanada
Authors: VEZINA L. 
Published: July 2006

Résumé:Des expériences ont été conduites sur terrain infesté par la prèle de champs, à Saint‐Simon, dans la province de Québec au Canada, du printemps 1985 à l'automne 1987. Elles ont été réalisées pour mesurer d'une part l'effet répressif de diverses successions d'interventions herbicides effectuées dans l'orge et le maïs‐grain cultivés en rotation et d'autre part l'influence de ces deux cultures sur l'évolution de trois peuplements de la prèle des champs. L'orge s'est avérée plus compétitive que le maïs‐grain à l'égard de la mauvaise herbe. L'orge a empêché les peuplements de prêle d'augmenter au fil des années alors que dans les parcelles de maïs‐grain les densités de tiges ont connu annuellement une hausse. Le MCPA amine utilisé tôt en post‐levée des cultures ne réprime la plante que temporairement et n'exerce après quelques années aucun effet significatif sur les densités de tiges. Dans le maïs, les applications d'une association de bromoxynil et de MCPA effectuées tardivement entre les rangs ont entraîné après deux années d'utilisation sur trois, une diminution de 8% de la densité des tiges dans le peuplement. Dans les parcelles témoins le nombre de tiges a augmenté en trois ans de 60%. L'application d'amitrole après la récolte de l'orge, sur une repousse de la plante et sur ses parties aériennes épargnées par le passage de la moissonneuse‐batteuse, a permis une répression efficace de longue durée. L'utilisation du MCPA aminé au cours des printemps suivants a retardé le rétablissement de l'adventice.
A mathematical model to predict Sorghum halepense (L.) Pers. seedling emergence in relation to soil temperature
Authors: ARNOLD R. L. BENECH , GHERSA C. M. , SANCHEZ R. A. , INSAUSTI P. 
Published: July 2006

Summary:A mathematical model to predict Sorghum hale‐pense seedling recruitment dynamics in relation to soil temperature was derived from the experimen‐tal results obtained in a previous investigation. The model is based on the assumption that soil temperature controls seedling recruitment of S. halepense by controlling release from dormancy and germination rate once dormancy breakage has been produced. The previous analysis sup‐plied mathematical functions to describe both the release from dormancy as controlled by tempera‐ture fluctuations, and the response to ‘thermal time’ after dormancy breakage. These relation‐ships were used in the construction of the model. This was tested against experimental field data with two differently aged seedbanks, in two seasons: spring and autumn. In each case in situ germination was monitored in plots with bare soil or soil surface shaded to simulate cover by a canopy. Soil temperature was recorded hourly and was used as an input of the model.A good description of seedling emergence dynamics in the field was obtained with the model, showing that seedling recruitment can be predicted using soil temperature data. The practi‐cal value of the developed model is discussed.
Glyphosate injury on Cyperus esculent us leaves and basal bulbs: histological study
Authors: CAÑAL M. J. , ALBUERNE M. , TAMÉS R. SANCHEZ , FERNANDEZ B. 
Published: July 2006

Summary:The effect of glyphosate on leaves and basal bulbs of yellow nutsedge (Cyperus esculentus L.) plants was studied. Treatment with glyphosate did not affect leaf anatomy, although light necrotic spots were seen on the veins. In contrast, basal bulb organization was greatly affected with large necrotic zones and disorganization in the vascular cylinder due to herbicide accumulation. Depletion or disappearance of vacuolar phenols was observed in bulbs of plants treated with the highest doses of glyphosate. The most remarkable effect of glyphosate was the appearance of one layer of sclerenchymatic cells between root and rhizome primordia and the cortical tissues which could play an important role in the inhibition of rhizome and root emergence by the herbicide.
Adsorption of transformation products of atrazine by soil
Authors: BROUWER W. W. M. , BOESTEN J. J. T. I. , SIEGERS W. G. 
Published: July 2006

Summary:The adsorption of atrazine and its transformation products, desisopropylatrazine (2‐chloro‐4‐ethylamino‐6‐amino‐l,3,5‐triazine), desethyl‐atrazine (2‐chloro‐4‐amino‐6‐isopropylamino‐l,3,5‐triazine) and hydroxyatrazine (2‐hydroxy‐4‐ethylamino‐6‐isopropylamino‐l,3,5‐triazine) to four top‐soils was measured. Adsorption coefficients decreased in the order hydroxy atrazine, atrazine, desisopropylatrazine, and desethyl‐atrazine: the distribution coefficient between organic matter and water (KOM) ranged from 40 to 100 dm3 kg−1 for atrazine, from 30 to 60 dm3 kg−1 for desisopropylatrazine, from 20 to 50 dm3 kg−1 for desethylatrazine and from 100 to 590 dm3 kg−1 for hydroxy atrazine. Data are discussed in the context of earlier literature.
Variations in the resistance of Stellaria media to mecoprop due to biotype, application method and 1‐aminobenzotriazole
Authors: LUTMAN P. J. W. , HEATH C. R. 
Published: July 2006

Summary:An investigation was made into the resistance of some biotypes of Stellaria media to mecoprop. Comparison of the sensitivity of five biotypes to foliar applications of mecoprop salt confirmed the presence of resistant and sensitive types and one of intermediate sensitivity. Applications of mecoprop through the roots of plants growing in nutrient culture were also more active on biotypes sensitive to foliar mecoprop, although the differences were less marked than they were with foliar treatments. Thus, possible differ ences in retention, uptake and translocation do not seem to be important causes of resistance. Consequently, it appears that resistance is associated with detoxification of mecoprop at the site of action. In two further experiments the cytochrome P450 mixed function oxidase inhibitor, 1‐aminobenzotdazole, had only a small effect on the susceptibility of resistant S. media plants to mecoprop. The importance of these data in the elucidation of the mechanism of resistance is discussed.
Effect of different levels of mannitol‐induced water stress on the tolerance of cultivated oat (Avena sativaL.) to didofop‐methyl
Authors: DASTGHEIB F. , ANDREWS M. , FIELD R. J. , FOREMAN M. H. 
Published: July 2006

Summary:The effect of degree of water stress inAvena sativaon diclofop‐methyl efficacy was assessed. Within 24 h of applying stress by adding mannitol to the root medium (0 to 12.5%), the rate of leaf extension of the youngest leaves (leaves 3 and 4) decreased with increasing mannitol concentration. Without water stress, application of diclofop‐methyl had little effect on extension rate of leaves 3 and 4 during the first 4 days after spraying. Subsequently, it caused a significant decrease in the extension rate of leaf 4 with more pronounced effects on later leaves. Diclofop‐methyl had little effect on leaf extension rate of plants given mannitol. Shoot dry weight at harvest for unsprayed plants decreased with increased mannitol concentration and for sprayed plants it was greater without mannitol than with mannitol (all levels). However, at mannitol concentrations greater than 4%, shoot dry weight for sprayed and unsprayed plants was not significantly different. Sprayed plants exposed to 2–8.5% mannitol produced seed heads but those at zero mannitol did not. When the root medium of all treatments was flushed of mannitol one week after spraying, then main‐tained without mannitol, shoot dry weight at harvest for unsprayed plants decreased slightly with increased mannitol concentration applied initially. However, shoot dry weight for sprayed plants increased with increased mannitol concentration. Without mannitol two weeks after spraying, chlorophyll concentrations of leaves 3 and 4 were greater and water saturation deficit (WSD) values were lower for unsprayed plants than sprayed plants but there were no differences at 6.2% mannitol. It is proposed that tolerance to diclofop‐methyl byA. sativaas a result of water stress, is primarily due to a decreased rate of leaf expansion resulting in lower demand for membrane synthesis and less strain on membranes damaged by the herbicide.
Predicting the growth and competitive effects of annual weeds in wheat
Authors: WILSON B. J. , WRIGHT KATHRYN J. 
Published: July 2006

Summary:The growth and competitiveness of 12 annual weed species were studied in crops of winter wheat, in which weeds were sown to give a wide range of plant densities. Weed growth patterns were identified; early species which senesced in mid‐summer were less competitive than those with a growth pattern similar to that of the crop. Most species had little effect on crop yield in 1987, and this was attributed to a high crop den sity. Crop yield‐weed density relationships for all species in 1988 and for Galium aparine in 1987 were well described by a rectangular hyperbola. Species were listed in the following competitive order based on the percentage yield loss per weed m−2: Avena fatua > Matricaria perforata > Galium aparine > Myosotis arvenis > Poa trivialis > Alopecurus myosuroides > Stellaria media > Papaver rhoeas > Lamiumpur‐pureum > Veronica persica > Veronica hederi‐folia > Viola arvensis. Prediction of yield loss is discussed. The assumptions inherent in using Crop Equivalents (based on relative weights of weed and crop plants), are challenged; with intense competition, weed biomass at harvest failed to replace lost crop biomass, and harvest index was reduced. It is concluded that a competi tive index, derived from yield density relation ships, and expressed as the percentage yield loss per weed m−2, is more likely to reflect the com petitive ability of a species than an index obtained from plant weights in the growing crop.
Differential toxicity of simazine and diuron to Torilis arvensis and Lolium rigidum
Authors: DE PRADO R. , SCALLA R. , GAILLARDON P. 
Published: July 2006

Summary:In a soil application, Torilis arvensis was nearly as susceptible as Lolium rigidum to simazine but was 18‐fold more tolerant to diuron. Treat ment with diuron inhibited photosynthesis in L. rigidum but had only a limited effect in T. arvensis although chloroplasts isolated from both species displayed similar susceptibility. 14C‐diuron degradation in plants was limited, with the formation of conjugates of mono‐methyl‐diuron in T. arvensis and N‐dealkylated derivatives of diuron in L. rigidum. 14C‐diuron entered the roots and was translocated throughout the leaves of L. rigidum but was restricted to stems, leaf petioles and leaf veins of T. arvensis. This difference in transport pattern is proposed to explain the tolerance of T. arvensis to diuron.
Fate of fluroxypyr in soil
Authors: LEHMANN R. G. , MILLER J. R. , OLBERDING E. L. , TILLOTSON P. M. , LASKOWSKI D. A. 
Published: July 2006

Summary:Fluroxypyr‐MHE (methylheptyl ester) was added to four soils and incubated at 26 ± 1°C and approximately 0.1 MPa moisture. After initial rapid hydrolysis of the ester to fluroxypyr, fluroxypyr degraded with half‐lives of 12, 12, 23, and 7 days in Barnes loam, Catlin silt loam, Hanford sandy loam, and Mhoon clay soils, respectively. Two metabolites (4‐amino‐3,5‐dichloro‐6‐fluoro‐pyridin‐2‐ol and 4‐amino‐3, 5‐dichloro ‐ 6 ‐ fluoro ‐ 2 ‐methoxypyridine) were identified, with the pyridinol at its maximum concentration after 2 to 4 weeks of incubation, and the methoxypyridine after 8 weeks. Degradation rates of fluroxypyr and its pyridinol were not significantly altered by diurnally varying soil temperature (21°C to 32°C) or moisture, nor by the presence of growing grass. Methoxypyridine dissipation was more rapid under greenhouse conditions, suggesting that laboratory studies underestimated the dissipation rate of this metabolite.