bluuebunny/crossref_metadata_2025 huggingface dataset:
THE USE OF CHEMICALS FOR THE POST‐HARVEST DEFOLIATION OF STRAWBERRY PLANTS
Authors: MASON D. T. , STEPHENS R. J.
Published: July 2006

Summary. Chemical sprays were used as alternatives to cutting for the post‐harvest defoliation of strawberry plants. Rapid desiccation of the foliage was obtained with dinoseb, sodium monochloroacetate, magnesium chlorate and sulphuric acid but the use of these chemicals normally resulted in lower yields than those obtained by mechanical defoliation. The reductions in yield appeared to be due to the less vigorous growth of the plants rather than to a lower level of inflorescence initiation.

L'utilisation de produits chimiques pour la défoliation après récolte des fraisiers
THE EFFECT OF SOME SEED CHARACTERISTICS ON 2,6‐DICHLOROBENZONITRILE TOXICITY
Authors: MILBORROW B. V.
Published: July 2006

Summary Seeds of thirty‐five species of plants were germinated in soil to which varying amounts of 2,6‐dichlorobenzonitrile had been added and the doses reducing growth by 50% (GID50) were obtained. An attempt was made to find correlations between growth rates, seed weights and fat contents and the GID50 values. There was no significant correlation with fat contents, but there was a significant correlation of increasing growth rate with increasing susceptibility and a negative correlation of seed size with susceptibility. Seed size was inversely related to growth rate so the extent to which either factor affects the sensitivity of the plants is uncertain. There was no significant difference between the mean sensitivities of monocotyledons and dicotyledons to 2,6‐dichlorobenzonitrile.

Effet de quelques caractéristiques de semences sur la toxicité du 2,6‐dichlorobenzonitrile
ÉTUDE DU COMPORTEMENT DU PEBC ET DE SON UTILISATION POUR LE DÉSHERBAGE DES BETTERAVES
Authors: Horowitz M.
Published: July 2006

Résumé. Une série d'essais de laboratoire et en plein champ ont été effectués pour étudier le comportement du PEBG (S‐propyl N‐butyl‐N‐éthylthiolcarbamate), et les possibilités de son utilisation pour le désherbage des betteraves, en comparaison d'autres herbicides.

Les pertes par volatilisation du PEBC ne paraissent pas constituer un facteur important de disparition lorsque l'herbicide est appliqué sur un sol sec, sans incorporation mécanique; l'activité herbicide est même accrue après une exposition de plusieurs jours à la sèche du sol. La teneur du sol en argile et en matière organique modifient l'activité du PEBC.

Dans les essais en plein champ sur betteraves sucrières, fourragères et potagères, le PEBC était pulvérisé, en pré‐semis ou en pré‐émergence, sur un sol sec, et l'herbicide était activé, après un intervalle allant de 12 h à 48 h, par une irrigation par aspersion ou par une pluie. En pré‐semis, on a comparé au Iraitement non incorporé, l'incorporation super‐ficielle par roulage et l'incorporation profonde par disquage; l'activité herbicide du PEBC était significativement inférieure quand on incorporait profondément. Dans deux essais de pré‐émergence, l'incorporation par roulage a été comparée à un traitement non incorporé; l'efficacité sur les mauvaises herbes sensibles au PEBC était un peu ineilleure quand la pulvérisation était suivie d'un roulage.

L'action du PEBC était très bonne contre les graminées annuelles et assez bonne contre Amaranthus spp. et Portulaca oleracea, qui constituent la majorité des advent ices infestant les champs de betteraves en Israël. Les crucifères étaient assez tolérantes et les adventices pérennes étaient résistantes. Les betteraves sucrières, fourragères et potagères ont toléré des doses de PEBC capables de réaliser un désherbage satisfaisant. L'activité du traitement a persisté durant 1 à 2 mois.

Dans les conditions sptéifiques de la culture betteravière en Israël, l'application du PEBC avant la levée, suivie éventuellement par un roulage, constitue done un traitement herbicide intéressant.

Studies on the behaviour of PEBC (S‐propyl N‐butyl‐N‐ethylthiolcarbamate) and its use for weed control in beet
DER GEGENWÄRTIGE VERBREITUNGSSTAND VON FLUGHAFER (AVENA FATUA L.) IN DER BUNDESREPUBLIK DEUTSGHLAND
Authors: BACHTHALER G.
Published: July 2006

Zusammenfassung. In den Jahren 1962–64 wurde in der Bundesrepublik Deutschland mit Unterstützung der Pflanzenschutzämter eine Erhebung über den gegenwärtigen Verbreitungsstand des Flughafers (Avena fatua L.) durchgeführt. Nach den ermittelten Ergebnissen kommt der Flughafer in allen Anbaulagen Westdeutschlands vom Norden bis zum Süden in unterschiedlicher Befalistärke vor. Es zeichnet sich allgemein eine Tendenz zur Zunahme der Verbreitungsgebiete ab. Die am stärksten mil Flughafer verseuchten Landschaftsräume deckcn sich grösstenteils mit den überwiegend auf Sommergerstenanbau konzentrierten Lagen. Die Verunkrautung mit Flughafer ist in Süddeutschland wesentlich ausgeprägter als in Norddeulschland, Ein kartographischer Vergleich des Flughafervorkommens in Westdeutschland von Zade aus dem Jahre 1909 und vom Verfasser aus dem Jahre 1965 zeigt deutlich, dass der Befall mit A. fatua gebietsmässig und nach der örtlichen Besatzdichte im Verlaufe von über fünf Jahrzchnten eine erhebliche Ausdehnung erfahren hat.

The present distribution of wild oat (Avena fatua L.) in the Federal German Republic
UNTERSUCHUNGEN ZUR KONKURRENZWIRKUNG VON KULTURPFLANZEN UND UNKRÄUTERN AUFEINANDER
Authors: UND W. KOCH , RADEMACHER B.
Published: July 2006

Zusammenfassung. Ein zweijähriger Vergleich der Entwicklung von Flughafer (Arena fatua L.) und Ackersenf (Sinapis arvensis L.) mit Sommergerste sowie von Ackerfuchsschwanz (Alopecurus myosuroides Huds.) mit Winterweizen brachtefolgendes Ergebnis:

Flughafer lief in beiden Jahren kurz vor der Gerste auf, entwickelte sich dann aber bis ungefahr zur Bestockung etwas langsamer als das Getreide. Die weitere Entwicklung ging bei beiden Arten weitgehend parallel. Die Reife der ersten Flughafersamen erfolgte kurz vor Ernte der Gerste.

Die Entwicklung des Ackersenfs war zunächst langsamer als die der Gerste, ungefähr von der Bestockung ab jedoch wesentlich rascher. Der Abschluss der Entwicklung erfolgte mehr als 10 Tage vor dem der Gerste.

Der Ackerfuchsschwanz lief 1962–63 vorwiegend im zeitigen Frühjahr, 1963–64 dagegen vorwiegend im Herbst auf. Infolgedessen war die Anfangsentwirklung in beiden Jahren recht unterschiedlich. Nach der Bestockung entwickelte sich der Ackerfuchsschwanz wesentlich rascher als der Weizen, so dass er wahrend seiner Blüte den Winterweizen überragte. Den Abschluss seiner Entwicklung erreichte der Fuchsschwanz etwas früher als der Weizen.

Beim Vergleich der Entwicklung von Ackerfuchsschwanz und Flughafer allein und in Konkurrenz mit dem Getreidc zeigte sich, dass der Entwicklungsrhythmus durch die Konkurrenz nicht wesentlich beeinflusst wurde, obwohl bei beiden Ungräsern durch das Getreide die Lange etwas und das Gewicht wesentlich vermindert wurden.
RÉSULTATS D'ESSAIS DE DÉSHERBAGE DU BLÉ D'HIVER AVEC LE PICLORAME
Authors: VERNIÉ F. , LHOSTE J. , CASANOVA A.
Published: July 2006

Résumé. L'acidc 4‐aniino‐3,5,6‐tricbloropicolinique (piclorame) a été expérimenté pour lutter conire Polygonum sp. et Matrîcaria sp. utilisé seul à la dose de 120 g é.a. ha ou assocîé a divcrses auxines de synthèse.

Utilisé seul le piclorame s'est révélé d'une efficacité rcmarquable sur Polygonum convolvulus L., P. aviculare L., Galium aparine L, et Matricaria inodora L. En revanche le spectre d'activité de ce produit est assez ètroit et on peut en particulier citer parmi les espècea résistantes à dose de 120 g é.a. ha: Fumaria ojficinalis L., Viola tricolor L., Cirsium arvense L, Sinapis sp. et Papaver sp. De plus la sé1ectivité du prodiul reste faible s'il n'eat pas utiliséà une époque bien définie qui correspond au moment où l'épi est à environ 1 cm du plateau de tallage.

Des quinze formulas expérimentées les associations permettant d'apportcrk l'ha 10 à 30g é.a. de piclorame associéà 240 g é.a de 2,4‐D plus 240 g é.a. de MCPA plus 1760 gé.a. de mécoprop assurent un contrôle trcs satisfaisant de Polygonum sp., Galium aparine, Matricaria inodora et Chrysanthemum segetum L. tout en gardant une bonne sélectivitéà l'égard du blé d'hiver.

Trial results with picloram for weed control in winter wheat
EFFECTS OF CHEMICAL WEED CONTROL ON THE GROWTH PATTERNS OF CONIFER TRANSPLANTS
Authors: GROVER R.
Published: July 2006

Summary. Studies were undertaken to determine the tolerance of three conifer species to repeated applications of several herbicides over a 2‐year period and the degree of weed control required to obtain optimal growth.

The results indicated that: (1) 60% or more weed control was required to obtain optimal growth of Picea glauca (Moench) Voss and P. pungens Engelm., while Pinus sylvestris L. showed optimal growth with average weed control as low as 40%; (2) weed competition did not affect the percentage survival of any of the three species under irrigated nursery conditions; (3) absence of visual injury symptoms was not an indication of the tolerance of a species to a herbicide; (4) severe weed competition caused an overall reduction in growth with significant reductions in stem diameter and in height and fresh weight of shoots; (5) herbicidal toxicity caused reductions in height, fresh weight or stem diameter but not necessarily of all three; (6) initial survival was affected only by those herbicides that were highly toxic at the doses applied; and (7) significant differences in growth, due either to weed competition or to herbicidal toxicity were apparent, in most instances, after the 2nd year's growth.

The treatments that gave 70% or more control each year with no apparent growth retardation over the 2‐year period of the three species tested were: single yearly applications of neburon 4 lb/ac or linuron 2 lb/ac, two applications each year of DCPA (dimethyl 2,3,5,6‐tetrachloroterephthalate) 10 lb/ac and directed application of sodium pentachlorophenate 15 lb/ac.
DECOMPOSITION OF LINURON IN DIFFERENT SOILS
Authors: LODE O.
Published: July 2006

Summary. A glasshouse experiment was performed in which linuron was added to five Norwegian soils. Chemical residue analysis and bioassay tests showed that the rate of decomposition varied for the different soils and that the linuron content which produced a reduction in growth of ryegrass seedlings varied with soil type. No leaching into the lower layers occurred. An initial depression in the numbers of bacteria and fungi present in the soils was observed, but the populations later recovered.
THE SYNERGISTIC ACTION OF HERBICIDE COMBINATIONS CONTAINING PARAQUAT ON AGROPYRON REPENS (L.) BEAUV.*
Authors: PUTNAM A. R. , RIES S. K.
Published: July 2006

Summary. Herbicide combinations containing paraquat were synergistic and provided control of established Agropyron repens (L.) Beauv. (quackgrass) sods for the entire growing season. Paraquat applied at 0–5 lb/ac with simazine or diuron at 4–0 lb/ac was more phytotoxic than either herbicide applied singly and the enhanced activity was more than additive. This synergism was not due to increased absorption or translocation of either herbicide in aerial portions of the plant. Paraquat applied to the shoot increased the susceptibility of quackgrass to simazine action through the soil. Pre‐treatment of quackgrass with aminotriazole or amitrole‐T at 10 lb/ac 7 days before paraquat application at 0–5 lb/ac provided increased toxicity over that obtained when the two herbicides were applied together or singly. Subsequent studies indicated that aminotriazole applications prior to shoot destruction by either paraquat or clipping resulted in more chronic aminotriazole toxicity. Using methyl‐14C‐paraquat it was found that aminotriazole pre‐loading also increased the movement of paraquat in and out of the treated leaf. This increase was even more pronounced with amitrole‐T. When the two herbicides were applied together, antagonism in absorption and translocation occurred.

Action synergique de combinaisons d'herbicides comprenant du paraquat sur Agropyron repens (L.) Beauv.
THE BASIS OF THE DIFFERENTIAL PHYTOTOXICITY OF 4‐HYDROXY‐3,5‐DI‐IODOBENZONITRILE*
Authors: DAVIES P. J. , DRENNAN D. S. H. , FRYER J. D. , HOLLY K.
Published: July 2006

Summary. Retention of the spray solution was shown to be a major factor in the selectivity of ioxynil. Retention was high on mustard plants with or without surfactant(Tween 20). Very little ioxynil was retained by barley and pea plants when no surfactant was included in the spray hut inclusion of 0.1 or 1.0% Tween 20 increased retention. With 1.0% the retention on pea plants approached that on mustard, and there was then little differential toxicity. With no surfactant in the spray, mustard plants retained twenty‐six times more ioxynil than barley plants. Addition of 01 or 1.0% surfactant increased retention by barley and reduced the differential to eleven times and eight times respectively. By varying the angle of barley leaves to the spray it was shown that the normal upright position results in reduced interception of a vertical spray and reflection of the drops without surfactant. It was concluded that for a given species growth reduction by ioxynil is largely conditioned by the amount retained and that apart from influencing retention, Tween 20 has no major independent action.

At equivalent retention levels barley was much less susceptible than mustard or pea. Plants of mustard, pea and barley were treated either on the leaves only or over the whole exposed surface of the plant lo assess the influence of morphology on the response to ioxynil. There was no difference in the response of barley, but treatment by dipping aerial shoots of mustard and pea produced an effect twice that from treatment of the leaves alone at the same level of retention. The increased response of mustard and pea to whole shoot treatment is considered to be due primarily to the exposed stem and bud tissues of these species.

Les bases de la toxicilé différentielle du 4‐hydroxy‐3,5‐di‐iodobenzomtrite I. Infiuence de la rétention de la bouillie et de la morphologie de la plante
STUDIES ON WEED SPECIES OF THE GENUS POLYGONUM L.
Authors: HAMMERTON J. L.
Published: July 2006

Summary. Seeds of Polygonum persicaria from several sources, or from plants subjected to in lain treatments, were chilled for varying periods and incubated for a 3‐week germination test period. Populations differed widely in seed weight and to some extent in the response to different periods of chilling. No relationship between this response and the climate of the locality of origin could be found. There was much variation in seed weight and germination behaviour between individual plants within populations. A total of four polymorphic seed categories were observed. The proportions of seeds in the two main categories varied widely between and within populations, and were affected by certain environmental factors. These factors also appeared to affect the degree of inter‐plant variation in seed shape and germination behaviour.

Travaux sur les espàes indésirables du genre Polygonum L. V. Variations dans le poids des semences, leur comportement à la germination et leur polymorphisme chez P. persicaria L.
THE HERBICIDAL EFFECT OF SOME α‐HYDROXY‐β,β,β‐TRICHLOROETHYLAMINO‐1,2,4‐TRIAZOLES
Authors: MATOLCSY G. , GOMAA E. A. A.
Published: July 2006

Summary. Four α‐hydroxy‐β,β,β‐trichloroethylamino‐1,2,4‐triazoles were prepared by the reaction of chloral hydrate with the corresponding aminotriazole and tested for herbicidal activity.

The introduction of the α‐hydroxy‐β,β,β‐trichloroethyl group into the aminotriazole molecule increased the activity of the parent compound. The increase in activity was slight with the highly active 3‐amino‐1,2,4‐triazole but was more marked with amino 1,2,4‐triazoles of low activity. The symptoms resembled those of the simultaneous action of 3‐amino‐l,2,4‐triazole with chloral hydrate or trichloroacetic acid.
A COMPARISON OF THE ‘VIBRAJET’ NOZZLE AND A FAN JET FOR OVERALL APPLICATION OF BIPYRIDYL HERBICIDES
Authors: DOUGLAS G.
Published: July 2006

Summary. The ‘Vibrajet’ nozzle is designed to produce relatively large droplets with ‘low drift’ characteristics. This system was evaluated for the overall application of paraquat, diquat and morfamquat in a number of agricultural situations in comparison with a fan jet. The biological efficiency achieved with the ‘Vibrajet’ nozzle was of the same order as that of the fan jet at the rates of application of the herbicides currently recommended in the United Kingdom. Five variables which affect the field performance of a spray system were investigated: volume of spray applied, concentration of wetter in the spray, rate of chemical applied, spray pressure and size of orifice. Changes in these factors made little improvement to the biological efficiency of the ‘Vibrajet’ nozzle.

Comparaisnn de la buse ‘Vibrajet’ et d'une bitse pinccau pom Vapplication generalisee des herbicides bipyridiliques
INTERACTION BETWEEN PARAQUAT AND MICROBES IN SOILS*
Authors: TU C. M. , BOLLEN W. B.
Published: July 2006

Summary. Laboratory experiments were conducted to determine if paraquat had any effect on soil micro‐organisms and consequently on soil fertility.

Numbers of bacteria and moulds tended to increase with incubation time as residual paraquat decreased. Lag periods of 1–5 days were observed in the development of soil microflora and concomitant degradation of paraquat. Under controlled culture conditions, Aerobacter aerogenes, Agrobacterium tumefaciens, Pseudomonas fluorescens and Bacillus cereus were able to utilize paraquat as sole carbon and nitrogen sources in synthetic media.

Paraquat at 0–25, 0–5, 2–5 and 25 ppm cation was added to four different soils to study changes in microbial activities concomitant with decreases in herbicide concentration. Analytical recoveries were correlated inversely with clay mineral content, cation‐exchange capacity and organic matter.

Mineralization of peptone nitrogen by amnnonification and nitrification was stimulated by 0–25 ppm; higher rates up to 25 ppm had little influence. A bimodal effect or growth inversion was observed in several instances, with increased microbial development at intermediate concentrations. Paraquat at recommended field rates appeared to have no appreciable influence on general microbial activities of importance to soil fertility.

Interaction entre U paraquat et les microbes dans les sols
SHOOT ZONE UPTAKE OF SOIL‐APPLIED HERBICIDES*
Authors: PRENDEVILLE G. N.
Published: July 2006

Summary. Studies were conducted to determine the effects of herbicide placement at different zones of maize (Zea mays L.) and pea (Pisum sativwm L.) shoots below the soil surface after emergence. Soil was removed from around the shoots and replaced with herbicide‐treated soil. A wax barrier ensured separate exposure of the zones to treated soil. EPTC, chlorpropham, propham and sulfallate did not affect pea shoot growth, but in maize the shoot zone adjacent to the crown root node was extremely sensitive. Treatment in this area markedly reduced growth and severely inhibited the crown roots. The difference in susceptibility between these species may he due to the location of the growing point relative to the treated soil.

Shoots of maize and pea were sensitive to diuron. In maize the shoot adjacent to the crown root node and the tissue of the first internode were the most susceptible. In pea the‐ uppermost shoot (beneath the soil surface) was the most sensitive. Trifluralin did not affect growth of maize and pea when placed in the shoot zone after emergence, although the crown roots of maize were severely inhibited. Naptalam, dalapon and 2,4‐D did not affect growth of maize under similar conditions, and of these only 2,4‐D reduced growth of pea.

Zone d'abiorption des tiges pour les herbicides appliqués sur h sol
THE EFFECT OF POST‐EMERGENCE HERBICIDES ON THE VEGETATIVE AND REPRODUCTIVE GROWTH OF CENTROSEMA FUBESCENS BENTH. IN QUEENSLAND
Authors: BAILEY D. R.
Published: July 2006

Summary. 2,4‐D‐amine, 2,4‐D ethyl ester, 2.4‐DB‐potassium. MCPA‐sodium, diquat and a 1:1 mixture of 2,4,5‐T butyl ester and 2,4‐D ethyl ester were applied to the tropical pasture legume Centrosema pubescens Benth. (centro) grown either alone or with Panicum maximum Jacq. (guinea grass). Even at 0.5 Ib/ac (total) the 2,4,5‐T/2,4‐D mixture caused severe damage to seedling and mature centro. 2,4‐D‐amine, 2,4‐D ethyl ester and 2,4‐DB‐potassium were less damaging and there were only slight differences in response to these. Diquat at 0.25 Ib/ac desiccated centro seedlings, but most plants survived and grew satisfactorily. There was some evidence that the growth of mature centro was depressed least when the herbicides were applied during vegetative quiescence.

Application just after the start of flowering altered the flowering pattern but did not reduce seed yields significantly. 2,4‐D‐amine at 0.75 and 1–5 lb/ac and 2,4‐D ethyl ester at 1.5 Ib/ac decreased the percentage germination of abraded seed. Diquat 0.25 Ib/ac applied at the start of flowering caused significant increases in top growth and seed pod numbers, possibly the result of modification of the normal flowering pattern.
THE ADSORPTION OF FOUR HERBICIDES BY DIFFERENT TYPES OF ORGANIC MATTER AND A BENTONITE CLAY*
Authors: DOHERTY P. J. , WARREN G. F.
Published: July 2006

Summary. A bioassay was used to study, adsorption of prometryne, simazine, linuron and pyrazon by fibrous peat, sphagnum moss, muck soil and bentonite as 1 % mixtures with quartz sand. Of these bentonite caused least reduction in bioactivity, and sphagnum moss reduced it only slightly more. Fibrous peat and muck soil were the most adsorptive. Prometryne, simazine and pyrazon were more highly adsorbed by fibrous peat than by muck soil, while for linuron the opposite occurred. Fibrous peat was approximately three, seven, thirteen and three times more adsorptive than bentonite for pyrazon, linuron, prometryne and simazine, respectively, while for muck soil the corresponding values were two, fourteen, seven and two.

Studies with prometryne and five different soils indicated that percentage organic matter, cation‐exchange capacity and specific surface area were all highly correlated with adsorption.
EFFECT OF DICAMBA ON OXYGEN UPTAKE AND CELL MEMBRANE PERMEABILITY IN LEAF TISSUE OF CYPERUS ROTUNDUS L.
Authors: MAGALHAES A. C. , ASHTON F. M.
Published: July 2006

Summary. The effect of the herbicidal compound dicamba (2‐methoxy‐3,6‐dichlorobenzoic acid) on the rate of oxygen uptake and on cell membrane permeability of leaf tissues of purple nutsedge (Cyprus rotundus L.) was studied. Dicamba induced noticeable alterations in both the pattern of oxygen consumption and in permeability of the cells following spraying of the foliar parts of the plants. A pronounced decrease in respiratory rate was observed 5 days after treatment with 10−3 M dicamba, but the rate of oxygen uptake rose to approximately the level of the control 10 days after application of the herbicide. Permeability of the cell membranes decreased 5 days after treatment of the leaves with 10−2 M or 10−3 M dicamba. The results indicate that the early disruption of the cell membranes might be related to the mode of action of the herbicide.
INCORPORATED VERSUS SUBSURFACE VERNOLATE FOR WEED CONTROL TN PEANUTS*
Authors: HAUSER E. W. , SAMPLES L. E. , PARHAM S. A.
Published: July 2006

Summary. Under dry field conditions, vernolate (S‐propyl dipropylthiocarbamate) incorporated by conventional methods controlled less yellow nutsedge (Cyperusesculentus L.) and injuied peanuts (Arachis hypogaea L., groundnuts) more than when injected in lines under the soil or subsurface‐applied through sweep applicators. In glasshouse studies, vernolate eliminated production of new nutsedge tubers if it was applied below the soil surface either 1 in. above or 1 in. below the parent tuber. Method of placement was less critical in determining control of most annual weeds.

When averaged over two soil types and 2 years, peanuts yielded 14% more after subsurface applications than after incorporated treatments of vernolate. In comparison with the optimum subsurface placement, the yield from incorporation was significantly lower in three of four field studies, the reduced yields probably resulting from a combination of herbicide injury and poor weed control. Factors affecting the distribution of vernolate vapours (such as method of placement, soil type and amount of rainfall after treatment) apparently determine the differential toxicity of this herbicide. Neither market quality nor germination of peanut seed was adversely affected by vernolate treatment.
THE EFFECT OF SIMAZINE ON THE PHOTOFIXATION OF CO2 AND ON TRANSLOCATION OF ASSIMILATES IN NORWAY SPRUCE (PICEA ABIES)
Authors: LUND‐HÖIE K.
Published: July 2006

Summary. A method of exposing seedlings of Norway spruce (Picea abies (L.) Karst.) to 14CO2 is described. Within the 1st hr alter 14CO2 exposure, no translocation of the 14C out of the treated branch could be observed. After a 24‐hr period, however, the 14C in dormant seedlings had been translocated basipetally to part of the root system only, with no lateral diffusion of the 14C‐compounds in the stem. About a week after exposure, both symplastic and apoplastic patterns of translocation had caused a more uniform distribution of 14C. In seedlings at active internode elongation, the translocation patterns were fundamentally identical to those in dormant seedlings, but the active shoot growth had led to a more uniform distribution of the 14C.

Simazine at 20 ppm had apparently stimulated both the photofixation of 14CO2 and the rate of translocation of the 14C‐assimilates. At 30 ppm, however, simazine had blocked the translocation of nutrients to the roots. On the other hand, the 14CO2 uptake was not influenced. The simazine incubation had apparently no influence on the synthesis of cationic photosynthate.
GROWTH AND STRUCTURAL MODIFICATIONS OF OATS INDUCED BY BROMACIL
Authors: ASHTON F. M. , GUTTER ELIZABETH G. , HUFFSTUTTER DONNA
Published: July 2006

Summary. Dry seeds of oat (Avena sativa L.) were placed in various concentrations of bromacil for 4 hr and then placed either on glasscloth which dipped into the herbicide solution, or with the roots in aerated herbicide solution. Root elongation was measured by two methods. Alter various exposure periods, selected portions of the plants were prepared by classical methods for examination with the light or electron microscope.

Total root elongation was inhibited by the concentrations used (10−6 to 10−3 M), and the degree of inhibition increased with increasing concentration. The inhibition was almost entirely restricted to the terminal 0.5 mm, the region of greatest elongation in untreated roots. Treated roots were swollen or necrotic and collapsed, with neerotic cells in the meristem, procambium and epidermis. There was also precocious vacuolation of cells in most tissues of the root tip, and inhibition of cell wall formation resulted in cells with multiple nuclei. The development of the chloroplast grana and fret system was inhibited by bromacil. The loculi of the grana and fret vesicles progressively swelled, and there was modification of the chloroplast envelope. These effects appear to be associated with loss of integrity of membranes.

Des semences sèches d'avoine (Avena sativa L.) furent placées dans diverses concentrations de bromacile pendant 4 heures puis placées ensuite soit sur de la laine de verre qui trenipait dans la solutjon herbicide, soit avec les racincs plongées dans une solution herhieide aérée. L'élongation des racines fut mesuree par detix methodes. Aprèa des periodes variees d'exposition, des portions choisies des plantes furent preparees par les methodes classiques pour cxamen au microscope ordinaire ou au microscope electronique. L'elongation totale des racines fut inhibde par les concentrations utilisees (10−6à 10−3 M), et le degré d'inhibition s'accrut avec l'augmentation des concentrations. L'inhibition fut presque entièrement localisée sur 0,5 mm á l'extrémité de la racine, région où se manifeste la eroissance la plus importante dans les racines non traitées. Les racines traitées apparuient gonflées, ou nécrosées et flasques, avec des cellules nécrosées dans le méristéme, le procambium et l'épiderme. Il apparut également une formation précoce de vacuoles dans les cellules dans la plupart des tissus de l'extrémité cs racines; de plus, l'inhibition de la formation de la paroi cellulaire provoqua la formation de cellules à noyaux multiples. Le développement des grana chloroplastes et du systéme lamellaire inter‐grana fut inhibé par le bromacile. Les cavités des grana et les vésicules du système lamellaire inter‐grana grossirent progressi vement et l'enveloppe des chloroplastes fut modifiée. Ces effets semblent être associés à la perte de l'intégrité des membrances.
INTERAKTION ZWISCHEN EINIGEN HERBIZIDEN BEI VORSAAT‐ UND VORAUFLAUFBEHANDLUNG IN ZUCKERRÜBEN
Authors: ZEMANEK J.
Published: July 2006

Im modifizierten logarithmischen Feldversuch mit ‘Kreuzparzellen’ wurden die Wechselbeziehungen zwischen Vorsaatbehandlung mit NaTCA bzw. Dalapon und Vorauflaufbehandlung mit Pyrazon bzw. Lenacil untersucht. Für jedes Kombinationspaar (NATCA+Pyrazon, Dalapon+Pyrazon, NaTCA+Lenacil, Dalapon+Lenacil) entstanden sechunddreissig Varianten. Dabei zeigte sich, dass auch NaTCA und Dalapon allein eine gewisse Wirkung gegen dikotyle Arten haben. Mit Steigenden Aufwandmengen an NaTCA bzw. Dalapon nahm in der Kombination mit Pyrazon bzw. Lenacil die Unkrautwirkung und in geringerem Masse auch die Phytotoxizität gegen die Rüben zu. Da bei der kombinierten Anwendung der genannten Vorsaat‐ und Vorauflaufherbizide die Empfindlichkeit der Rüben weniger Stark zunahm als die der Unkräuter, wurde zumindest unter den im Versuch gegebenen Bedingungen die Selektiviät nicht vermindert.

The interaction between herbicides applied before sowing and pre‐emergence in sugar beet
EFFECTS OF CONSTITUENTS OF GRAMOXONE W ON RATES OF RESPIRATION OF SOIL FUNGI
Authors: WILKINSON VALERIE , LUCAS R. L.
Published: July 2006

Summary. The effects were determined of paraquat dichloride and Lissapol NX, consutuents of the commercial formulation Gramoxone W, on the rate of oxygen uptake by cultures of Fusarium cutmanmt and Trkkoderma viride. When applied separately, paraquat dichode was less inhibitory than the wetting agent; when applied together, the inhibitory effect was greater than the sum of those obtained separately. Synergism was also observed between paraquat dichloride of commercial purity and a solution containing the additives used m Gramoxone W but without the paraquat dichloride. This effect is thought to be due to increased permeation of paraquat dichioride into fungal mycelia in the presence of a wetting agent. Older cultures were less affected than younger ones by the coniponents of Gramoxone W. The results suggest that the additives used in formulating herbicides may be critical in determining fungitoxicity.

Effets des constituants du Gramoxone W sur les taux de respiration de champignons du sol
ABSORPTION, TRANSLOCATION AND METABOLISM OF DICHLOBENIL IN BEAN SEEDLINGS
Authors: VERLOOP A. , NIMMO W. B.
Published: July 2006

Summary. A quantitative study was carried out on the absorption, translocation and metabolism of 2,6–dichlorobenzonitriie‐14G (dichlobenil) in seedlings of Phaseolus vulgaris L. From an aqueous solution dichlobenil is absorbed by the roots and accumulates about three‐fold; metabolism in the roots is of minor importance. From the roots the herbicide is translocated throughout the plant. In the leaves two competitive processes take place: the main part (90%) of the dichlobenil evaporates and another part is metabolized. The principal metabolic pathway is hydroxylation, followed by conjugation, 3–hydroxy‐2,6–clichlorobenzonitriIe and 4–hydroxy‐2,6–dichlorobenzonitrile analogues being formed in a ratio of about 4:1. Hydrolysis of dichlobenil into 2.6–dichlorobenzamide and 2,6–dichlorobcnzoic acid is only a minor metabolic route.

From a saturated atmosphere dichlobenil is taken up rapidly through the leaves but little translocation occurs to the roots. Following foliage application more of the applied dichlobenil Is metabolized because evaporation of dichiobenil as a competitive process is virtually eliminated.

Absorption, migration ei métabolisme du dichlobenil dans les plantules de haricot
CHEMICAL CONTROL OF IMPERATA CYLINDRICA (L.) BEAUV. IN MALAYSIA*
Authors: SETH A. K.
Published: July 2006

Summary. Paraquat‐based treatments were evaluated for the control of Imperata cylindrica (L.) Beauv., a perennial grass with extensive rhizomes of great regenerative power. Single applications of 0–5 lb/ac paraquat gave good initial control, but regeneration was rapid. Increases up to 2–0 lb/ac had little effect on the duration of control, nor did the volume rate from 40 to 120 gal/ac. When an initial application of 05 lb/ac was followed by two further applications of 0–25 lb/ac, when the level of control had decreased to 50%, lasting control was obtained. Application of 6–8 lb/ac dalapon followed by 0–25 lb/ac paraquat also gave good control, comparable with that achieved by the conventional treatment of dalapon alone at 15–20 lb/ac.

La lutte chimique contre Imperata cylindrica (L.) Beauv. en Malaisie

Résumé. Des traitements utilisant le paraquat ont étè essayés pour lutter contre Imperata cylindrica (L.) Beauv., graminée pérenne avec des rhizomes importants qui manifestent un pouvoir de régénération élevé, Des applications uniques de paraquat à la dose 0,56 kg/ha ement un bon eifel initial mais la régéneration fut rapide. L'accroissement de la dose jusquà 2,2 kg/ha n'eut qu'une faible incidence sur la durée de l'action herbicide, l'augmentation du volume de traitement de 450 à 1350 1/ha ne provoqua pas non plus d'augmentation de I'efficacité. Une seule application de paraquat à 0,56 kg/ha, quand le niveau de I'efficacité eut décru jusquà 50%, suivie de deux applications supplémen‐taires à 0,275 kg/ha, donna une efficacité plus durable. Des applications de dalapon de 6,7 à 9,0 kg/ha suivies de traitements au paraquat à 0,275 kg/ha donnèerent un résultat aussi bon que celui obtenu par les traitements habituels au dalapon seul, à la dose dc 16 à 22 kg/ha.

Chemisehe Bekampfung von Imperata cylindrica (L.) Beauv. in Malaysia

Zusammenfassung. Es erfolgten Untersuchungen zur Bekämpfung von Imperata cylindrica (L.) Beauv., einem mehrjährigen Gras mit einem ausgedehnten Rhizomsystem und starker Regenerationskraft, mit Paraquat, Einmalige Applikation von 0,56 kg/ha Paraquat hatte zwar eine gute Anfangswirkung, doch erfolgte rasche Regeneration. Eine Erhöhung bis auf 2,2 kg/ha war ebenso wie eine Änderung der Spritzbrühmenge von ca 450–1350 I/ha von geringem Einfluss auf die Nachhaltigkeit der Bekämpfungs‐massnahmen. Eine einmalige Anwendung von 0,56 kg/ha Paraquat gefolgt von zwei weiteren Applikationen von 0,28 kg/ha, wenn die Regeneration ungelahr 50% erreicht hatte, ergab nachhaltige Wirkung. Behandlungen mit 6,7‐9 kg/ha Dalapon gefolgt von 0,28 kg/ha Paraquat hatten ebenfalis eine gute Wirkung, die mit der einer konven‐tionellen Behandlung mit 16,8‐22 kg/ha Dalapon vergleiehbar war.
THE HERBICIDAL ACTIVITY OF 2‐AMINO‐3‐CHLORO‐1,4‐NAPHTHOQUINONE
Authors: HAGIMOTO H.
Published: July 2006

Summary. Incubation of 2‐ammo‐3‐chloro‐l,4‐naphthoquinone (ACNQ), a potential herbicide for transplanted paddy rice (Qryza sativa L.), with rice seedlings led to rapid inactivation; in the absence of plants, the concentration was unaltered.

The rate of disappearance increased with seedling age, and with number of seedlings per unit volume of solution. Only small proportions of the amounts disappearing could be extracted from the plants. Fresh homogenates of rice and Echinochloa crus‐galli (L.) Beauv. also caused inactivation, while heated homogenates had less effect. It is suggested that AGNQ is inactivated in the course of its herbicidal action and that if plants remain alive after complete inactivation, they can resume normal growth.

Activity herbicide de la 2‐amitto‐3‐ckloro‐1,4‐napktoquinone. III. Mode d'action et inactivation

Résumé. L'incubation, en présence de plantules de riz, de la 2‐amino‐3‐chIoro‐1,4‐naphtoquinone, herbicide utilisable sur le riz repiqué, aboutit à une rapide inactivation du produit, alors qu'en I'absence de plantes, la concentration resta inchangée.

Le taux de destruction s'accrut avec l'âge des plantules et avec le nombre de plantules par unité de volume de la solution. Il ne put être extrait des plants que de faibles fractions des quantités du produit disparu. Des homogénats frais de riz et d'Echinochloa crus‐galli (L.) Beauv. provoquèrent également une inactivation; cependant des homogénats chauffés se montrèrent moins actifs, II est suggéré que l'AGNQ est inactive au cours de son action herbicide et que, si des plantes restent encore en vie après inactivation complète, elle peuvent recouvrer leur croissance normale.

Die herbizide Aktivität von 2‐Amino‐3‐chlor‐1,4‐Naphthoquinon. III. Wirkungsweise und Inaktivierung

Zusammenfassung. Inkubation von 2‐Amino‐3‐chlor‐1,4‐naphthoquinon (ACNQ), einem potenticllen Herbizid für gepflanzten Sumpfreis (Oryza sativa L.), mit Reiskeim‐pflanzen, führte zu einer raschen Inaktivierung der Substanz, während die Herbizidkonzentration in Abwesenheit von Pflanzen unverändert blieb.

Die Verlustmenge nahm mit dem Alter der Keimpflanzen und deren Anzahl pro Volumeneinheit der Nährlösung zu. Nur geringe Teile der verschwundenen Herbizidmenge konnten aus den Pflanzen extrahiert werden. Frische Homogenisate von Reis und Echinochloa crus‐galli (L.) Beauv. inaktivierten das Herbizid ebenfalls, während erhitzte Homogenisate weniger wirksam waren. Es wird vermutet, dass ACNQ im Verlaufe seiner herbiziden Wirkung inaktiviert wird und dass die Pflanzen, wenn sie nach der vollständigen Inaktivierung am Leben bleiben, ihr normalea Wachstum wieder aufnehmen können.
SEASONAL GERMINATION PATTERNS OF POA TRIVIALIS L. AND SUBSEQUENT PLANT BEHAVIOUR
Authors: BUDD E. G.
Published: July 2006

Summary. Seeds of Poa trivialis L. were sown monthly on bare ground in South‐East England during 1967–68 and the germination and development patterns recorded. The seeds germinated under a wide range of atmospheric temperature and soil moisture conditions. In winter, however, germination was slower to begin and more prolonged than during the summer. Seedlings germinating before the winter produced more and earlier seed heads the following spring than those germinating during the winter and spring.

It is suggested that spring‐sown cereal crops, and delayed stubble cultivations of old infested grass seed crops, should be investigated as measures to control Poa trivialis.

Aspects de la germination saisonnière de Poa trivialis L. et comportement vltérieur de la plante

Résumé. Des graines de Poa trivialis L. ont été semées chaque mois sur le sol nu, dans le sud‐est de l'Angleterre en 1967–68; la germination et le développement ont été notés. Les semences germèrent dans des conditions très variés de température de I'air et d'humidité du sol. Toutefois, en hiver, la germination fut plus lente à démarrer et se prolongea plus longtemps que durant l'été. Les plantes provenant de germination avant l'hiver produisirent au printemps suivant des tiges fertiles plus précocement et en plus grande quantityqué celles issues de germinations durant l'hiver et le printemps.

Ceci suggére que la culture des céréales de printemps et les déchaumages tardifs des terres infestées depuis longtemps par des gramintées devraient être étudiées comme moyens de lutte contre Poa trivialis.

Verlauf der Keimung von Poa trivialis L. in Abhängigkeit von der Jahreszeit und das nachfolgende Verhalten der Pflanzen

Zusammenfassung. Während der Jahre 1967–68 wurden in Südostengland monatlich Samen von Poa trivialis L. auf unbewachsenen Boden gesät und der Verlauf von Keimungund Entwicklung aufgezeichnet. Die Samen keimten innerhalb eines weiten Bereichs der Lufttemperatur und Boden Feuchtigkeit. Jedoch begann die Keimung im Winter langsamer und erstreckte sich uber einen langeren Zeitraum als im Sommer. Noch vor dem Winter gekeimte Sämlinge bildeten im folgenden Frühjahr die Samenstände früher und in grösserer Anzahl aus als jene, die erst während des Winters und Frühjahrs keimten. Es wird vorgeschlagen, Frühjahrsaussaat des Getreides und verzögerten Stoppelumbruch befallener Getreideanbauflächen als Massnahmen zur Bekämpfung von Poa trivialis zu überprüfen.
THE TOXICITY OF PARAQUAT TO A RANGE OF SPECIES FOLLOWING UPTAKE BY THE ROOTS*
Authors: DAMANAKIS M. , DRENNAN D. S. H. , FRYER J. D. , HOLLY K.
Published: July 2006

Summary. The sensitivity of eight species to paraquat taken up through the roots was tested in nutrient solution experiments. Ryegrass, lettuce and carrot, which were found to be the most sensitive, were assessed for response to paraquat in a peat soil. Lettuce and ryegrass were the most suitable of the eight species for soil bioassays.

Toxicité du paraquat pour diverses espéces aprés absorption par les racines

Résumé. La sensibilité de huit espéces au paraquat absorbé par les racines a étéétudiée dans des experiences en solutions nutritives. Le ray‐grass, la laitue et la carotte qui se sont montrés les plus sensibles furent employés pour évaluer la réaction au paraquat dans un sol tourbeux. La laitue et le ray‐grass furent, parmi les huit espéces, les plus appropriate aux essais biologiques.

Phytotoxizitdt von Paraquat gegeniiber einer Anzahl von Arten nach Wurzelaufnahme

Zusammenfassung. Die Empfindlichkeit von acht Arten gegenuber Paraquat nach Wurzel Aufnahme wurde in Wasserkulturversuchen untersucht. Weidelgras, Salat und Möhren hat ten sich als am empfindlichsten erwiesen und wurden auf ihre Reaktion gegenuber Paraquat in einem Lehmboden untersucht. Salat und Weidelgras erwiesen sich von den acht untersuchten Arten als die beiden geeigneuten für Bodenbiotests.
BIOLOGICAL ACTIVITY OF SUBTERRANEAN RESIDUES OF CYNODON DACTYLON L., SORGHUM HALEPENSE L. AND CYPERUS ROTUNDUS L.*
Authors: HOROWITZ M. , FRIEDMAN THERESA
Published: July 2006

Summary. .

Dried subterranean organs of Cynodon dactylon, Cyperus rotundus and Sorghum halepense were incubated in light and heavy soils for 1, 2 or 3 months. After removal of the decayed plant material, the residual bioactivity of the soil was assayed by barley sown directly into the soil and by a barley radicle‐length test on an ethanolic extract of the soil. The two assays gave similar results. In general, the inhibition of growth was proportional to the concentration of plant material in the soil, and was greater in light than in heavy soil. Greater inhibition was caused by C. rotundus and S. halepense than by C. dactylon. A few instances of growth stimulation were recorded.
STUDIES ON WEED SPECIES OF THE GENUS POLYGONUM VII. EFFECT OF NUTRITION AND OTHER FACTORS ON SEED CHARACTERISTICS AND GERMINATION BEHAVIOUR OF P. LAPATHIFOLIUM
Authors: HAMMERTON JOHN L. , NUTTALL M.
Published: July 2006

Summary. .

Plants of Polygonum lapathifolium were grown either in a glasshouse or outside, at a high or a low level of mineral nutrition, and either with or without competition from barley. The viability and percentage emergence of seedlings from germinated seeds (planted in sterile compost) were higher with seed from glasshouse‐grown plants. High nutrition increased plant weight, seed production and seed weight, and also increased seedling emergence. Competition reduced plant weight, but had only a small, non‐significant, effect on seed production. Seed from plants grown with competition had a greater percentage seedling emergence from germinated seeds.
RESIDUAL ACTIVITY OF PARAQUAT IN SOILS II. ADSORPTION AND DESORPTION
Authors: WATKIN E. M. , SAGAR G. R.
Published: July 2006

Glasshouse studies showed that low doses of paraquat inhibited the germination of Lolium perenne L. broadcast directly onto the paraquat‐sprayed surfaces of a sphagnum and a peat soil, but that higher doses were necessary to produce phytotoxic symptoms on mineral soils, a compost and a loam. On all soils residual activity increased rapidly with increasing dose once the minimum phytotoxic dose was reached. On a sandy soil, residual activity increased almost linearly from the lowest to the highest dose applied.

At 9·0, 4·5 and 2·24 kg/ha phytotoxicity on a compost was not affected by changes in the volume of application, but at 1·68 kg/ha and lower, reducing the volume from 562 1/ha to 281 and 112 1/ha resulted in increased phytotoxicity.

Phytotoxic residues were eluted from paraquat‐treated compost surfaces by percolating de‐ionized water up soil columns but residual activity was not removed from the eluted surfaces. Surface irrigation of paraquat‐treated surfaces with water previously percolated through columns of untreated soil reduced residual activity by 45%.
THE EFFECT OF REPEATED FIELD APPLICATIONS OF FOUR HERBICIDES ON THE EVOLUTION OF CARBON DIOXIDE AND MINERALIZATION OF NITROGEN IN SOIL
Authors: GROSSBARD E.
Published: July 2006

The effect of repeated annual applications over 7‐8 years of MCPA, triallate, simazine and linuron to field plots on the evolution of CO2 and mineralization of nitrogen in soil samples incubated in the laboratory is described. The plots were either cropped and treated with standard doses, or uncropped and sprayed with doses 3‐4 times above the level used in agricultural practice. While the applications of MCPA and tri‐allate did not exert any inhibitory effects in soils from the uncropped plots those of simazine and linuron led to a lowering in CO2 output in several instances and in mineral N on infrequent occasions. These effects are assumed to be the result of a difference in the content of easily‐degradable organic matter between the treated plots and the controls. A direct anti‐microbial action of the two herbicides is not very probable because in laboratory experiments with simazine up to 512 ppm the output of CO2 and the mineralization of N was not affected while linuron at 500 ppm gave only a minor depression in CO2 evolution. Effects on soil fertility are unknown but seem unlikely in view of the small extent and infrequency of the reductions observed. On the cropped plots the MCPA and tri‐allate treatment showed no effects. With linuron and simazine a significant lowering in respiration and mineralization of N occurred on single occasions only, during a 5‐year period.