bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF LIGHT INTENSITY, PHOTOPERIOD AND NITROGEN ON THE GROWTH OF SEEDLINGS OF AGROPYRON REPENS (L.) BEAUV. AND AGROSTIS GIGANTEA ROTH
Authors: WILLIAMS E. D.
Published: July 2006

Summary. Seeding of Agropyron repens (L.) Beauv. und Agrostis gigantea Roth were grown in two photoperiods and with amounts of nitrogen. On two occasions plants transferred between photoperiods.

The early growth of the seedlings was increased most by increasing the light intensity, but later nitrogen had the greatest effect. In short photoperiods, plants of both species were decumbent and had many more shoots than in long photoperiods. At the end of the experiment, plants of both species responded more to nitrogen in bright than in dim light, and the dry weight of Agropyron was increased more than that of Agrostis by increased photoperiod and nitrogen.

Agropyron initiated rhizomes sooner than Agrostis; it had fewer rhizomes but they were longer and thicker and weighed more. Brighter light, longer photoperiod and nitrogen all increased rhizome weight. Photoperiod did this mainly by producing more rhizomes, light by increasing thickness or density, and nitrogen by both. The effects of photoperiod and nitrogen on the rhizome dry weight of Agropyron, but not of Agrostis, were additive.

Transferring plants from short to long photoperiods or from long to short, respectively increased or decreased total growth, but had an opposite effect on the rhizomes.
Germination of Seeds of Cirsium arvense (L.) Scop.
Authors: KUMAR V. , IRVINE DAVID E. G.
Published: July 2006

Cirsium arvense (L.) Scop. is a persistent and troublesome weed which reproduces vegetatively. Establishment from seeds (achenes) is considered negligible under natural conditions in the United Kingdom (Bates, 1946), although germination under normal farm conditions was found to be good in America (Hansen, 1918). Korsmo (1930) in Norway and Hayden (1934) in Iowa found that the seeds had no dormancy period, but Niethammer (1934) and Zilke (1967) recorded seed dormancy in Germany and South Dakota respectively. An examination was therefore made of some of the factors which may regulate the germination of seeds of C. arvense in this country.
DEGRADATION OF BROMOXYNIL IN REGINA HEAVY CLAY*
Authors: SMITH ALLAN E.
Published: July 2006

A spectrophotometric method was developed to detect bromoxynil in Regina heavy clay, and the breakdown under different temperature and moisture conditions was studied. At rates equivalent to 14 kg/ha, over 50% of the applied bromoxynil was degraded in 2 weeks at 25°C and at moisture levels in excess of the wilting point. Losses at 18°C were slightly slower. Little breakdown occurred in sterile soil, indicating that microbial degradation could be an important factor contributing to bromoxynil breakdown under field conditions.

Paper and thin‐layer chromatographic techniques were used to isolate and identify soil degradation products. In addition to the parent compound small amounts of 3,5‐dibromo‐4‐hydroxybenzamide and 3,5‐dibromo‐4‐hydroxybenzoic acid were detected.
REGENERATIVE CAPACITY OF ROOT FRAGMENTS OF CIRSIUM ARVENSE (L.) SCOP.
Authors: HAMDOUN A. M.
Published: July 2006

Summary. Root fragments less than 5 mm long were unable to form shoots. However, shoots were produced by fragments 10 mm long and 1 mm in diameter, unless originating from immature apical regions. The number of shoots per unit length of root was greater if the root was cut into many small pieces than into a few long ones. The ability to produce shoots was apparently unrelated to the presence or absence of visible buds.

Root fragments showed polarity; most of the shoots originated from the basal (proximal) end and the roots from the apical (distal) end. Soil moisture content had relatively little effect upon growth from a fragment unless the soil was waterlogged or very dry for prolonged periods. Growth from fragments was prevented by temperatures below 5°C; optimum growth occurred at 15°G. Shoots from fragments 25 mm long emerged successfully from depths of 50 cm.

Capacité de régenération de fragments de racines de Cirsium arvense (L.) Scop.
A SPLIT‐ROOT TETRAZOLIUM METHOD FOR EVALUATING EFFECTIVENESS AND PHYTOTOXICITY OF ROOT‐ACTIVE HERBICIDES
Authors: DUFFY SPENCER L.
Published: July 2006

Summary. Copper sulphate (GUSO4.5H2O) and sodium hydroxide (NaOH) were used to test the performance of a split‐root method for evaluating the effectiveness and phytotoxicity of root‐active herbicides. This method involves a vertical separation of the root system of weeping willow (Salix babylonica L.) cuttings. One section is treated with the herbicide dissolved in half‐strength Hewitt's medium while the other remains in medium without herbicide during the test period. Roots are assayed with 2,3,5‐triphenyttetra‐zolium chloride 24 h after treatment to determine their viability. Both herbicides satisfactorily reduced the viability of the treated roots as measured by the quantity of formazan extracted. Copper sulphate was systemic and injured untreated plant parts; sodium hydroxide affected only treated roots. The split‐root tetrazolium method is relatively rapid and does not require sophisticated laboratory equipment.

Méthode au tétrazolium sur portions de racines pour l'évaluation de l'efficacité et de la phytotoxicité des herbicides agissant par les racines
BEKÄMPFUNG VON GALIUM APARINE MIT MECOPROP IN ABHÄNGIGKEIT VON VERSCHIEDENEN BODENARTEN
Authors: SCHMIDT ROBERT R.
Published: July 2006

Zusammenfassung. Die Bekämpfung von Galium aparine L. mit Mecoprop im Nachauflaufverfahren ist abhangig sowohl von der Pflanzengrösse ab auch vor allem vom Boden, in dem die Pflanzen wachsen:

 Kleine Pflanzen werden leichter vernichtet als grosse.

 Pflanzen, die auf einem Boden mit hohem organischen Anteil wachsen, sind gegen Mecoprop widerstandsfähiger als solche, die auf einem Boden mit niedrigem C‐Gehalt wachsen.

Ein Teil der im Nachauflaufverfahren gespritzten Herbizidmenge gelangt auf den Boden und wirkt zusätzlich durch Aufnahme über die Wurzeln.

Diese zusätzlichc herbizide Wirkung ist auf den Bodenproben I und II mit hohem organischen Anteil geringer als auf dem Boden mit niedrigem C‐Gehalt. Als Ursache der geringeren Wirksamkeit ist eine verstärkte Adsorption des Mecoprop in den Bodenproben I und II gegenüber Boden III verantwortlich.

Als Adsorbens kommt nur die organlsche Substanz der Bodenproben in Frage.

Der zu erzielende Gesamtbekämpfungserfolg hängt neben der Aufnahme des Mecoprop über das Blatt auch von der zusätzlichen Wirkung des Herbizids über den Boden ab.

Control of Galium aparine with mecoprop in relation to soil type
MORPHOLOGICAL, ANATOMICAL AND BIOCHEMICAL EFFECTS OF PROPACHLOR ON SEEDLING GROWTH*
Authors: DHILLON NIRMAL S. , ANDERSON J. LaMAR
Published: July 2006

Summary. The root and shoot growth of oat (Avena saliva L.) and squash (Cucurbita maxima Duchesne) was reduced in proportion to propachlor concentration. Corn (Zea mays L.) root growth was inhibited only by concentrations of 16 ppm and higher. Cell division in onion (Allium cepa L.) root tips was reduced by propachlor and totally inhibited by 16 ppm. Auxin‐induced cell elongation of oat coleoptiles was inhibited in proportion to propachlor concentration. Propachlor treatment prevented the normal senescence of squash cotyledons by inhibiting the autolysis of proteinaceous and lipid reserves.

Effets morphologiques, anatomiques et biochimiques du propachlore sur la croissance des plantules Riisumi.
THE EFFECT OF CHLORMEQUAT SEED‐PARENT TREATMENT ON THE RESISTANCE OF WHEAT SEEDLINGS TO TERBUTRYNE AND SIMAZINE
Authors: PINTHUS MOSHE J.
Published: July 2006

Summary. The effects of pre‐sowing treatments with terbutryne (4‐ethylamino‐2‐ niethylthio‐6‐t‐butylamino‐1,3,5‐triazine) and with simazine (2‐chloro‐4,6‐bisethyl‐amino‐1,3,5‐triazine) on seedling mortality of wheat grown from regular seed and from seed containing about 40 ppm chlormequat (2‐chloroethyl trimethylammonium chloride), due to a late chlormequat treatment of the seed‐parent, were tested in two pot experiments. In another pot experiment the effects of pre‐sowing and post‐emergence treatments of terbutryne on dry matter accumulation and moisture content in SPT (= Seed‐Parent Treated) and regular wheat seedlings were examined.

No significant differences in simazine resistance between regular and SPT seed were found. However, there was a marked and significant increase in terbutryne resistance of SPT over regular seeds, which was expressed by a longer period to 50% seedling mortality as well as by a lower daily increase in mortality. Growth retardation, caused by pre‐ sowing as well as by post‐emergence terbutryne treatments, was appreciably less in the SPT seedlings than in the regular ones. The higher terbutryne resistance of the SPT seedlings may be attributable to their higher moisture content induced by the chlormequat.

Effet du traitement des pieds meres avec le chlorméquat sur la résistance des plantules de blé a la terbutryne et à la simazine
SHOOT ZONE UPTAKE OF SOIL‐APPLIED HERBICIDES IN PISUM SATIVUM L.
Authors: O'BRIEN L. P. , PRENDEVILLE G. N.
Published: July 2006

Summary. The effects of localized herbicide placement at different internodes of pea (Pisum sativum L. cv. Alaska) shoots below the soil surface after plant emergence were studied by removing the soil from around the shoots and replacing with herbicide‐treated soil. The first internode proved insensitive to linuron, diuron, atrazine and simazine at 4·5 kg/ha, while treatment of the second and third internodes markedly reduced plant growth 4–6 days after treatment. Separate exposure of the first internode alone, and the second and part of the third together to 14C‐labelled atrazine indicated no difference in herbicide metabolism. However, a two‐ to threefold increase in 14C uptake and movement to the foliar parts occurred when the second and part of the third internode was treated, as compared to first internode treatment. Thus the differential sensitivity of the internodes to atrazine, and possibly to the other herbicides, may be because the more mature first internode allows less uptake and subsequent movement to the foliar parts.

Absorption dans la zone des tiges des herbicides appliqués dans le sol chez Pisum sativum L.
THE EFFECTS OF SOME CHEMICALS ON THE GERMINATION OF A WEED, PSORALEA CORYLIFOLIA L.
Authors: SHUKLA S. P.
Published: July 2006

Summary. The effects of 2,4‐D, 2,4,5‐T, IAA and GA on the germination behaviour of one‐seeded pods of Psoralea corylifolia L. were studied. For each chemical, inhibition of germination of acid‐scarified pods increased with increase in concentration. The inhibition was irreversible and led to death of the seed in the pod. Morality, expressed as percentage of dead pods, was highest for 2,4,5‐T and IAA and lowest for GA. Impermeable or ‘hard’ pods were unaffected by the treatments. Though acid‐scarified pods were significantly damaged by an 8 h chemical treatment, weathered pods were unaffected by treatments of less than 30 h duration. After scarification, dry pods were more susceptible than pre‐imbibed ones. Rates of water uptake were determined for pods of both categories.

Effets de quelgues produits chimiques sur la germination de Psoralea corylifolia L.
GROWTH, TUBER FORMATION AND SPREAD OF CYPERUS ROTUNDUS L. FROM SINGLE TUBERS*
Authors: HOROWITZ MENASHE
Published: July 2006

Summary. Single tubers of Cyperus rotundus L. were planted at intervals over the year. Plant growth was slow and sprouting of tubers was inhibited at temperatures below 20°C, but tubers overwintered at temperatures above freezing point. In the warm season, plant growth and tuber formation rate closely followed air temperature and tubers were forming within 1 month from planting. No inflorescence appeared during the cool season.

In autumn‐planted C. rotundus grown in containers, the ratio of aerial to subterranean weight decreased from 1·1 in December to 0·2–0·4 in summer. The weight of tubers in mid‐summer was about 10 times more than that present in December.

Tubers formed at ail times of year and at various locations on plants sprouted readily in laboratory tests (76–100% sprouting).

C. rotundus planted in March at wide spacings was grown in field conditions free of other plant competition for 20 months. Within 2 months the plants had spread to 90 cm. At the end of the first and the second summer of growth, the mean area of one plant was 7·6 m2 and 56·7 m2, respectively, and patches had expanded then by 2·8 m and 5·4 m, respectively, from the initial shoot. After 20 months of growth all tubers were present within the 0–40 cm soil depth, 60–70% of them in the 0–20 cm layer. About 30% of the tubers were within 1 m and 60% within 2 m of the plant centre.

Under the patch centre there were about 1000 tubers per m2 with 0·3 kg dry weight; in the upper 20 cm more than 3500 tubers weighing 0·9 kg were present per m3 of soil.

Croissance, formation de tubercules et propagation de Cyperus rotundus L. issu de tubercules uniques
SOME PHYSICO‐CHEMICAL INTERACTIONS OF PARAQUAT WITH SOIL ORGANIC MATERIALS AND MODEL COMPOUNDS
Authors: BURNS I. G. , HAYES M. H. B. , STACEY M.
Published: July 2006

Summary. The adsorption equilibria of paraquat were investigated on a range of organic materials including an organic soil, various humic fractions of that soil, model polymers prepared by the oxidative coupling of benzoquinone, ion‐exchange resins (Zeo‐Karb 216 and 226) and a polystyrene resin (Amberlite XAD‐2). Isotherms were prepared for adsorption on the H+ and on some of the Ca2+ saturated materials. Measurement of the counter‐ion in solution at equilibrium, and correlation of the adsorption with exchange capacity for H+ adsorbents showed that ion exchange was the primary adsorption mechanism. Significant amounts of non‐exchange adsorption were also detected, especially at low concentrations, but generally the results followed the Rothmund‐Kornfeld isotherm equation fairly accurately. The Rothmund‐Kornfeld plots for the Ga2+ forms were complicated by the hydrolysis by water of some of the exchange sites. Other types of isotherm equations were tested and found to be unsatisfactory.

Desorption of paraquat with HCl from organic soil preparations was less than expected, and the isotherms did not conform to the Rothmund‐Kornfeld or to the mass action equations. The probable reasons for this behaviour arc discussed.

Quelques interactions physico‐chimiques du paraquat avec des matériaux de sol organique et des composés modèles

II. Adsorption, désorption et équilibre dans les suspensions aqueuses
Note on the Estimation of Viable Weed Seeds in Soil Samples
Authors: FEAST PATRICIA M. , ROBERTS H. A.
Published: July 2006

Techniques for estimating populations of viable weed seeds in soil can be grouped into those which involve sieving, flotation and subsequent viability determination, and those which rely on direct assessment of the seedlings arising from the soil samples (Kropáč, 1966). This germination technique, although undoubtedly useful, may be less efficient than extraction methods (Jensen, 1969) and has the disadvantage that the samples must be kept for a long period to ensure that germination of a high proportion of the seeds takes place. Experiments were made to examine some of the factors which might affect seed germination in soil samples placed in shallow dishes, and the results are summarized in this note.
TEMPERATURE VARIATIONS IN THE SURFACE LAYERS OF AN AGRICULTURAL SOIL*
Authors: STOLLER E. W. , WAX L. M.
Published: July 2006

Summary. Continuous measurements of soil temperatures were made at 1·3, 2·5, 5·1, 10·2, 15·2 and 20·3 cm below the barren surface of a Drummer silty clay loam during 1969. Annual average temperature at all these soil levels was higher than the air temperature 122 cm above the soil surface. The daily fluctuations in soil temperatures were greater in summer than in winter and were greater down to depths of 5·1 cm than the fluctuations in air temperature. The maximum and minimum temperatures for the year, of the air, 1·3‐cm and 20·3‐cm depths were 34 and ‐ 19,46 and ‐ 18, and 33 and ‐ 8°C, respectively. On near cloudless days, the soil temperatures showed a pattern of amplitude reduction and phase retardation with depth, as the soil layers warmed and cooled.

Variations de la température dans les couches super ficielles d'un sol agricole
A TECHNIQUE FOR STUDYING THE RATE OF ROOT GROWTH OF INTACT SEEDLINGS IN A HERBICIDE MEDIUM
Authors: O'SULLIVAN P. A. , PRENDEVILLE G. N.
Published: July 2006

Summary. Time‐lapse cine photography was used to record intact seedling root growth of pea and barley during separate exposure of root, shoot + seed, or entire needling to herbicides. The shoot + seed and the root zones were isolated in two square Petri dishes fixed edge to edge, and separately treated with moistened herbicide‐treated sand. The seated dishes were placed at an angle of 30° in a photographic chamber. Photographs of roots were automatically recorded at 10‐min intervals on 16 mm high speed reversal film over 72 h. Root length images on film were measured using an ocular micrometer. Root growth of pea and barley seedlings was normal when the shoot + seed zone was treated with 2,4‐D at 1 and 10 ppm, respectively. In similar treatment of roots growth inhibition occurred after approximately 20 h in both plants, and root growth ceased alter 32 h in peas, and 57 h in barley. These results indicate the inherent tolerance of barley roots to 2,4‐D.

Technique pour l'étude du taux de croissance des racines intactes de plantules dans un milieu herbicide
THE INTERRELATIONSHIP BETWEEN TILLERS AND RHIZOMES OF POA PRATENSIS L.—AN AUTORADIOGRAPHIC STUDY
Authors: NYAHOZA FELIX , MARSHALL C. , SAGAR G. R.
Published: July 2006

Summary. The main shoot or selected tillers of seedling plants of Poa pratensis L. were supplied with 14CO2 and the distribution of 14C‐assimilates was followed by autoradiography. The primary tillers were initially supplied with 14C‐assimilates from the main shoot but, once established, became independent of the parental shoot for carbohydrates. Similarly, developing rhizome‐tillers were supported by the main shoot and established primary tillers but soon became self‐supporting, Defoliation of all the tillers of the plant but one led to the defoliated primary and rhizome tillers being supplied with radiocarbon from the remaining intact shoot. Thus, although the primary tillers and rhizome‐tillers in the intact plant appear to be physiologically independent, the entire tiller‐rhizome system may be re‐integrated after defoliation, allowing assimilate redistribution. P. pratensis may be regarded as a convenient link between the non‐weedy herbage grasses which generally lack rhizomes and the weedy rhizomatous grasses typified by Agropyron repens (L.) Beauv.

Etat des relations entre les talles et les rhizomes de Poa pratensis L. Etude autoradiographique
AMINOTRIAZOLE METABOLISM IN CIRSIUM ARVENSE (L.) SCOP. AND PISUM SATIVUM L.
Authors: SMITH LEON W. , CHANG FA‐YAN
Published: July 2006

Summary. Excised leaves as well as intact plants of Canada thistle (Cirsium arvense (L.) Scop.) metabolized 3‐amino‐l,2,4‐triazole (aminotriazole) to three major products, Unknowns II, 1a and 1b. Unknown II was identical to β‐(3‐amino‐l,2,4‐triazolyl‐l‐)α‐alanine. Unknowns 1a and 1b, previously described as one product, were separated by electrophoresis and thin layer chromatography. Unknown 1a appeared to be a metabolic product of Unknown II while Unknown 1B was derived from Unknown 1a. An enzyme preparation from pea (Pisum sativum L. cv. Thompson Laxton) seedlings capable of synthesizing tryptophan from indole and serine was also able to metabolize aminotriazole. Tryptophan synthesis with the enzyme preparation was inhibited by aminotriazole and evidence suggests that aminotriazole metabolism may follow a similar pathway to tryptophan synthesis.

Métabolisme de l'aminotriazole chez Cirsium arvense (L.) Scop, et Pisum sativum L.
DEGRADATION OF DICAMBA IN PRAIRIE SOILS
Authors: SMITH ALLAN E.
Published: July 2006

Summary. Electron‐capture gas chromatography was used to detect dicamba residues in three prairie soils, and the breakdown under different moisture conditions was studied. At rates equivalent to 1·1 kg/ha degradation was rapid in all soils at 25°C and at moisture levels in excess of the wilting point, with over 50% of the applied dicamba being dissipated in 2 weeks. Negligible breakdown occurred in the sterile soils, over a 4–week period, indicating that microbial decomposition could be an important factor contributing to dicamba degradation.

The persistence of dicamba was investigated under field conditions at three locations using small plots. Applications equivalent to 1·1 kg/ha were made in October 1971 for analysis in May 1972, and in May 1972 for analysis in August 1972. At both sampling dates no dicamha residues were detected in any of the treatments at the 0–5, 5–10 or 10–15 cm soil levels.

Degradation du dicamba dans les sots de prairies
SELECTIVITY OF BENZENE SULPHONYL CARBAMATE HERBICIDES BETWEEN DIFFERENT GRASS SPECIES AND CLOVER
Authors: BLAIR A. M. , HOLROYD J.
Published: July 2006

Summary. In field experiments extending over the period 1964–68 wettable powder and water soluble formulations of asulam and M & B 8882 were applied to a range of grass species in summer and autumn. Phleum pratense L., Dactylis glomerata L., Holcus lanatus L., Agrostis tenuis Sibth. and Poa trivialis L. were more susceptible than Lolium perenne L., Festuca pratensis Huds. and Festuca rubra L., although effects were more persistent on H. lanatus than on the other species. Trifolium repens L. (white clover) was more resistant to M & B 8882 than to asulam, particularly in July. The pattern of selectivity was similar with summer and autumn treatment, but effects were slower to develop in the autumn.

Sélectivité des herbicides a base de carbamate de benzène sulfonyle entre différentes espèces de graminées et le trèfle
VERTICAL DISTRIBUTION OF HERBICIDES IN SOIL AND THEIR AVAILABILITY TO PLANTS: SHOOT COMPARED WITH ROOT UPTAKE
Authors: WALKER A.
Published: July 2006

Summary. Turnip, lettuce and ryegrass seedlings showed toxicity symptoms following shoot exposure to atrazine, linuron and aziprotryne at soil concentrations less than would be obtained from normal field applications. Responses following shoot exposure to simazine and lenacil were much less. Root exposure to all five herbicides caused seedling death at concentrations lower than those required for ‘shoot‐zone’ toxicity. Pronamide and chlorpropham were tested against ryegrass only and at the concentrations examined were toxic only when localized in the shoot zone. Root exposure suppressed root growth, but the shoots were able to grow normally if the soil was kept sufficiently moist. Shoots contained more 14C‐atrazine at emergence after shoot exposure compared with root exposure, but there was little subsequent uptake from the shoot zone. There was extensive uptake from the root zone after emergence. In the shoot‐zone treatments, concentrations in the plant were high at emergence but were rapidly diluted by plant growth, whereas with root exposure, they increased throughout the experiments. The possible significance of these results to herbicide bebaviour under field conditions is discussed.

La distribution verticale des herbicides dans le sol et leur disponibilité pour les plantes: absorption comparée par la partie aèrienne et par les radnes
Environmental control of dormancy and germination in the seeds of Cenchrus longispinus (Hack.) Fern.
Authors: TWENTYMAN J. D.
Published: July 2006

Summary: Résumé: Zusammenfassung

Seed dormancy and germination in sand burr (Cenchrus longispinus (Hack,) Fern,) were investigated in laboratory and field studies. The burrs contain two types of seeds which differed in their innate dormancy. Primary seeds formed in the upper spikelet usually germinated within a year. Secondary seeds from lower spikelets germinated slowly and remained dormant for longer periods. Dormancy was enforced at low and high temperatures, and secondary seeds apparently developed an induced dormancy when continuously exposed to high temperatures. More than 94 % of the seedlings established during spring. Light suppressed germination, and secondary seeds also developed an induced dormancy when stored in the light. Burrs sown on the soil surface had an extended period of germination lasting for more than 3 years. However, over 96 % of the seeds sown below the surface of bare soil germinated within 2 years. Deep burial did not enforce dormancy, but germination was suppressed by the presence of live vegetation. It is concluded that treatments which disturb the soil and bury the burrs will stimulate the germination of dormant seeds.
Description d'une methode de dosage biologique de la simazine dans le sol
Authors: BOUCHET F. , DAGNEAUD J. P.
Published: July 2006

Résumé: Summary: Zusammenfassung

Une méthode de dosage biologique de la simazine dans le sol a été mise au point en utilisant la moutarde blanche (Sinapis alba L.) et l'avoine (Arena sativa L.) comme plantes de référence. Les échantillons de sol étudiés ont été prélevés dans des parcelles ayant reçu chaque année pendant 10 ans des doses de 1 kg, 3 kg on 6 kg/ha de simazine. Le dosage biologique, dont les résultats sont interprétés statistique‐ment, n'a mis en évidence que des quantités très faibles d'herbicide (0,25 à 0,48 kg/ha de matière active dans le sol des parcelles traitées à 6 kg/ha), alors que des doses deux ou trois fois plus élevées avaient été décelées par un dosage chimique.

Beschreibung eines Biotests für Simazin im Boden

Es wurde ein Biotest zum Nachweis von Simazin im Boden vervollkommnet bei dem Weisser Senf (Sinapis alba L.) und Hafer (Avena fatua L.) verwendet werden. Die untersuchten Bodenproben stammten aus Parzellen die zehn Jahre lang jährlich mit 1, 3 und 6 kg/ha Simazin behandelt worden waren. Die Ergebnisse des Biotests, die statistisch verrechnet wurden, zeigten für die Parzellen die mit 6 kg/ha behandelt worden waren nur sehr geringe Herbizidmengen (0–25 bis 048 kg/ha A.S.). Durch die chemische Analyse wurden hingegen zwei‐bis dreimal höhere Mengen nach‐gewiesen.

Description of a bio‐assay technique for simazine in soil

A bio‐assay method for the determination of simazine in the soil was perfected using white mustard (Sinapis alba L.) and oat (Avena sativa L.) as the reference plants. The samples of soil studied were taken from plots treated annually with simazine at 1, 3 or 6 kg/ha for 10 years. The bio‐assay, the results of which can be statistically interpreted, revealed only very small quantities of herbicide (0.25 to 0.48 kg/ha of active ingredient in plots treated at 6 kg/ha), whereas amounts two or three times greater were detected by chemical analysis.
Viable seeds and spores of weed species in peat soil under pineapple cultivation*
Authors: WEE Y. C.
Published: July 2006

Summary: Résumé: Zusammenfassung

Soil samples were taken from twenty‐two fields in a peat area in W. Malaysia where pineapples had been grown for different periods. The numbers of viable seeds and spores in the top 15 cm of fields under cultivation for 6 months, 2, 6 and 10 years varied from 66–122 millions/ha. Of this total, 90% were spores of Nephrolepis biserrata and eight other ferns. The total numbers of seeds of the two sedges, one grass and nine dicotyledons recorded, ranged from 0–7 to 6.3 millions/ha.

Les semences et spores viables de mauvaises herbes en sol tourbeux dans des plantations d'ananas

Des échantillons de sols ont été prélevés dans vingt‐deux champs dans une zone tourbeuse en Malaisie occidentale oü les ananas ont été cultivés pendant des périodes différentes. Les nombres de semences et spores viables dans les 15 premiers centimétres du sol dans les champs mis en culture depuis 6 mois, 2, 6 et 10 ans ont varié de 66 ä 122 millions/ha. Sur ce total, 90 %étaient des spores de Nephrolepis biserrata et de huit autres fougéres. Le nombre total de semences des deux roseaux, de la graminee et des neuf dicotylédones dont la présence dut notée, fut compris entre, 0,7 et 6,3 millions/ha.

Lebensfähigen Unkrautsamen und sporen im Moorboden unter Ananas

In einem Moor in W. Malaysia wurden aus 22 Feldern die unterschiedlich lang unter Ananas standen, Bodenproben entnommen. Die Zahl an lebensfähigen Samen und Sporen in den obersten 15 cm der Felder, die 6 Monate, 2, 6 und 10 Jahre lang unter Ananas standen, schwankte von 66 bis 122 Millionen je ha. Von dieser gesamten Menge waren 90% Sporen von Nephrolepis biserrata und acht anderen Farnen. Die Gesamtzahl an Samen von zwei Seggen, einem Gras und neun dikotylen Arten, belief sich auf 0,7 bis 6,3 Millionen jeha.
Some effects of paraquat on crop establishment in killed swards
Authors: WARBOYS I. B.
Published: July 2006

Summary: Résumé: Zusammenfassung

The establishment of crops direct‐drilled after various times into swards treated with paraquat (1,1′‐dimethyl‐4,4′‐bipyridylium‐ 2/A) was examined. Best results with Brassica napus and B. oleracea were obtained with 1–1 kg/ha applied 7 days before drilling and 2–3 kg/ha applied 14 days before. Although delaying drilling from 7 to 14 days after application reduced the phytotoxicity, the higher dose was needed when drilling was delayed, to reduce competition from the sward regrowth. In the glasshouse, mulches of paraquat‐treated herbage affected seedling growth and development of Brassica napus, Hordeum vulgare and Lolium perenne; B. napus was the most susceptible.

Quelques effets du paraquat sur des cultures implantées aprés destruction d'herbages

L'implantation de cultures en semis direct, apres divers intervalles de temps, dans des herbages trait6s au paraquat (l,r‐diméthyl‐4‐4′‐bipyridylium‐2/4) a été examinée. Avec Brassica napus et B. oleracea, les meilleurs résultats ont été obtenus par des applications de 1,1 kg/ha et de 2,3 kg/ha, respectivement 7 jours avant et 14 jours avant le semis. Bien que le fait de porter de 7 à 14 jours le délai entre le traitement été le semis ait réduit la phytotoxicité, la dose la plus forte a été nécessaire lorsque le semis a été retardé, pour réduire la competition due à la repousse de la prairie. En serre, des paillis d'herbages traités au paraquat ont affecté la croissance et le développement de Brassica napus, Hordeum vulgare et Lolium perenne; B. napus s'est montré le plus sensible.

Einige Effekte von Paraquat auf die Entwicklung von Kulturpflanzen in abgetöteten Pflanzendecken

Es wurde die Entwicklung von Kulturen untersucht, die in unterschiedlichen Zeitabständen direkt in mit Paraquat (l,l'‐Dimethyl‐4,4′‐bipyridylium‐2/4) behandelte Pflanzendecken gesät wurden. Die besten Ergebnisse mit Brassica napus und B. oleracea wurden erzielt, wenn 1.1 kg/ha 7 Tage und 2 3 kg/ha 14 Tage vor der Saat gespritzt wurden.
Effects of picloram on shoot anatomy of red maple and white ash
Authors: PETERSON R. L. , STEPHENSON G. R. , MITCHELL B.J.F.
Published: July 2006

Summary: Résumé: Zusammenfassung

The anatomy of the shoot system of red maple and white ash was examined at various times after treatment with picloram. Xylem blockage, enlargement of cortical and pith cells and eventual necrosis of the shoot apex, parenchymatous and phloem tissues of red maple plants were features shown by picloram treatment. Red maple shoots were desiccated and dead by 22 days after treatment commenced. White ash shoots showed some increased mitotic activity but at the end of 22 days of picloram treatment, the leaves were still turgid and the internal anatomy of the shoot system scarcely altered. It is suggested that the susceptibility of red maple plants can be explained in part by the effects picloram has on xylem blockage and necrosis of parenchymatous tissues in the shoot system of this species.

Effects du piclorame sur l'analomie de la partie aérienne de l'erable rouge et du frêne blanc

L'anatomie de la partie aérienne de l'érable rouge et du frêne blanc a été examinee i diverses dpoques aprés un traitement au piclorame. Le blocage du xyléme, le grossissement des cellules corticales et médullaires, ainsi qu'une Éventuelle nécrose des apex des tiges, des tissus parenchymateux et du phloéme des Arables rouges furent les effects consécutifs au traitement par le piclorame. La partie aérienne des Arables rouges se déssécha et mourut 22 jours aprés le dé

A but du traitement. La partie aérienne du Fréne blanc manifesta un accrolssement d'activité mitotique. mais, 22 jours aprés le traitement au piclorame, les feuilles étaient encore turgesccntes et l'anatomie interne des organes aériens k peine altérte. II est suggéré que la sensibility de rérable rouge peut être expliquée en partie par les effets du piclorame sur le blocage du xyléme et les necroses des tissus parenchymateux dans les organes adriens de cette espèce.

Die Wirkung von Picloram auf die Anatomic des Sprosses von Acer rubrum L. und Fraxinus americana L.

Es wurde die Anatomie des Sprosssystems von Acer rubrum L. und von Fraxinus americana L. zu verschiedencn Zeiten nach einer PJilorambehandlung untersucht. Bei Acer rubrum traten als Sympiome auf: Verstopfen des Xylems, VergröBerung der Rinden‐und Markzellen und schliesslich Absterben der Sprossspitze, des parenchymatischen und des Phloemgewebcs. 22 Tage nach der Behandlung waren dis Sprosse ausgelrocknet und tot. Bei Fraxinus americana zeigten die Sprosse erhohte mitotische AktivitSt, aber 22 Tage nach der Piclorambehandlung waren die Blotter noch turgeszent und der innere Auf bau des Sprols systems war kaum verSndert. Die Befunde deuten darauf hin, daβ die Empfindlichkeit von Acer rubrum gegenuber Pictoram zum Teil mit seiner Wirkung auf das Xylem und das parenchymatische Gewebe im Sproβsystem erklärt werden kann.
Ecology and control of blackberry (Rubus fruticosus L. agg.) II. Reproduction*
Authors: AMOR R. L.
Published: July 2006

Summary: Résumé: Zusammenfassung

The reproduction of blackberry (Rubus fruticosu L. agg.) is described with particular reference to R. procerus P.J. Muell. Reproduction is by seed, rooting at cane apices, suckering of lateral roots, and from pieces of roots and canes.

In Victoria, Australia, R. procerus occurs mainly in non‐agricultural land and neglected pastures and is rare in well‐managed pastures and crops. This is attributed to the poor establishment of seedlings and the ease with which rooting at cane apices may be prevented by grazing, cultivation or spraying with 2,4,5‐T.

To eradicate established thickets it is necessary to kill the roots by frequent cultivation or to apply herbicides lo prevent the formation of root suckers.

Ecologie des ronces (Rubus fruticosus L. agg.) et méthodes dc lutte II Reproduction

La reproduction des ronces (Rubus fruticosus L. agg.) est décrite avec une reference particulière au R. procerus P. J. Muell. La reproduction s'opère par les semences, l'enracine‐ment d'apex de tiges, la formation de drageons À partir de racines laterales et de fragments de racines et de tiges.

Dans l'Etat de Victoria, en Australie, R. procerus apparaît surtout dans les terres non cultivées et les pâtures mal entretenues; cette espèce est rare dans les pâtures bien entretenues et dans les cultures. Ce fait est attribuéà la difficile implantation des plantules et h la facility avec laquelle la formation de drageons à partir des apex des tiges peut être prévenue par le pâturage, les façons culturales, ou le traitement au 2,4,5‐T.

Pour éliminer les fourrés élablis, il est nécessaire de tuer les racines par des façons culturales fréquentes et d'appliquer des herbicides pour prévenir la formation de drageons à partir des racines.

Ökologie und Bekämpfung der Brombeere (Rubus fruticosus L. agg.) II. Vermehrung

Es wird die Vermehrung der Brombeere (Rubusfrur ic osus L. agg.) unter besonderer Berucksichtigung von Rubus procerus P.J. Muell. beschrieben. Die Vermehrung erfolgt durch Samen, Bewurzelungvon Sprossspitzen (Ruten), Bildung von Wurzelsprossen aus Seitenwurzein und durch Wurzel‐und Sprossteile.

In Victoria, Australien. kommt R. procerus hauptsächtich auf nicht landwirtschaftlich genutzten Flächen und auf vernachliissigten Weiden vor, selten dagegen auf gut gep‐flegten Weiden und auf Ackerland. Dies ist auf das geringe Ausbreitungsvermogen der Samlinge und auf die einfache Verhinderung der Bewurzelung der Sprosspitzen durch Beweiden, Bewirtschaftung oder Spritzung mit 2,4,5‐T zurückzuführen.

Um ein altes Dickicht auszurotten ist cs notwendig, die Wurzeln durch mehrmalige Bodenbearbeitung abzutöten oder durch Herbizidspritzung die Ausbildung von Wurzelsprossen zu verhindem.
Penetration of bracken fronds by asulam as influenced by the addition of surfactant to the spray solution and by pH
Authors: BABIKER A. G. T. , DUNCAN H. J.
Published: July 2006

Summary: Résumé: Zusammenfassung

Asulam (methyl(4‐aminobenzenesulphonyl)carbamate) does not penetrate rapidly on foliar application to bracken (Pteridium aquilinum). Its performance is therefore erratic if rain follows immediately after spraying. The addition of the surfactant polyoxyethylene sorbitan monolaurate (Tween 20) increased spray retention and doubled penetration of asulam by the bracken frond. Concentrations of Tween 20 greater than 01 % (w/v) gave no further increase in penetration and pH had no effect.

Pénéetration de l'asulame dans les frondes de fougiré: influence de l'addition d'un mouillant a la bouillie herbicide et du pH

L'asulame (méthyl(4‐aminobenzinsulfonyl)carbamate) ne pénètre pas rapidement lorsqu'il est appliqué par voie foliaire sur la fougére (Pteridium aquitinum). En conséquence, son efficacité est irrégulière s'il plcut immédiatement apres le traitement. L'addition d'un mouillant, le Tween 20 ou monolaurate de polyoxyéthylène sorbitol a augmenté la rétention de la pulvérisation et a doublé la pénétration de l'asulame dans les frondes de fougères. Les concentrations de Tween 20 supérieures à 0,1 % (pds/vol) n'ont pas augmenté la pénétration et le pH s'est montré sans effet.

Der Einfluss von Netzmittetzusatz und pH auf die Penetration von Asulam in Wedel des Adterfarns

Asulam (N‐(4‐Amino‐benzolsulfonyl)‐carbaminsäure‐methyl‐ester) dringt in Adlerfarn (Pteridium aquilinum) bei Blattapplikation nicht schnell ein. Deshalb ist seine Wirkung unzuver‐lässig, wenn es unmittelbar nach der Spritzung regnet. Der Zusatz des Netzmittels Polyoxyäthylensorbitanmonolaurat (Tween 20) erhöhte die Retention der Spritzbrühe und verdoppelte die Penetration von Asulam in die Adlerfarnwedel. Höhere Konzentrationen von Tween 20 als 0,1 % (Gew./Vol.) steigerten die Penetration nicht und das pH spielte keine Rolle.
Photosynthetic inhibition in Phaseolus vulgaris
Authors: VAN OORSCHOT J. L. P.
Published: July 2006

Similar injuries to the leaves of bean plants (Phaseolus vulgaris L. cv. Berna) were produced by exposure to CO2‐free air in the light and by ireatnient with simeton. The rate of production of leaf injuries and the degree of photosynthetic inhibition induced in plants exposed to CO2‐free air increased with exposure time and with light intensity. Exposure to CO2‐free nitrogen delayed the onset of the inhibition and the development of the injuries. These results showed some analogies with the action of herbicides which affect photosynthesis.
Photosynthetic inhibition in Phaseolus vulgaris II. The influence of light on herbicidal action
Authors: VAN OORSCHOT J. L. P. , VAN Leeuwen P. H.
Published: July 2006

The influence of pre‐treatment and post‐treatment illumination upon the herbicidal effect produced in Phaseolus vulgaris L. cv. Berna by simeton, diuron, diquat and ioxynil was examined. The increased effect noted at lower pre‐treatment and higher post‐treatment levels of illumination was correlated with increased inhibition of net photosynthesis. This increased effect was ascribed to enhanced photo‐oxidation.
Effects of repeated applications of ten soil‐active herbicides on weed population, residue accumulation and nitrification*
Authors: HOROWITZ M. , BLUMENFELD T. , HERZLINGER G. , HULIN NIRA
Published: July 2006

Ten herbicides, bromacil, chlorthal‐dimethyl, diphenamid, diuron, fluometuron, neburon, prometryne, pyrazon, simazine and trifluralin at two doses were repeatedly sprayed, in autumn and in spring, for 4 consecutive years on non‐cultivated, sprinkler‐irrigated field plots. Herbicidal effect was assessed at 1–2 month intervals on the natural weed population and after each observation a paraquat + diquat spray destroyed emerged weeds. The response of various weed species to herbicides varied markedly but a herbicide‐induced shift in the composition of weed population did not occur, presumably because of the paraquat treatment.

The overall phytotoxicity to weeds present was, in decreasing order: diuron, bromacil, simazine, trifluralin, prometryne, neburon, fluometuron, pyrazon, diphenamid, chlorthal‐dimethyl. Persistence of herbicides was in decreasing order: diuron = bromacil, simazine, neburon (at higher rate), fluometuron, trifluralin, prometryne. Control produced by pyrazon improved with the number of applications, but that of diphenamid and chlorthal‐dimethyl remained weak and short. After repeated applications, the activity of these herbicides increased or remained at similar level, but in no case decreased.

Soil samples were taken 5 months after each application and bioassayed. Phytotoxic residues were detected beneath the disturbed top‐soil from bromacil, diuron, fluometuron and simazine after the first application, and from neburon after the second application; residues from trifluralin were found in the top soil only after the fifth application. After the seventh spraying, residues of bromacil were found in the 45–60‐cm soil layer.

Ammonia content in soil samples taken from treated plots after the fourth, sixth and seventh application was generally similar to the untreated control. In these samples, nitrate content appeared to be correlated negatively with remaining weed number; the control thus contained less nitrate than efficient herbicidal treatments. Soil samples taken after the seventh application of bromacil, diuron, fluometuron, neburon and simazine, which contained appreciable residual concentrations, did not show significant differences from control, in an in vitro nitrification test.
Development of a new small‐plot sprayer and some predictions of the field performance
Authors: BLATR A. M. , TAYLOR W.A. , TOTTMAN D.R.
Published: July 2006

Summary: Résumé: Zusammenfassung

A sprayer to apply herbicides to 1‐m2 plots in the field in a manner closely related to conventional spraying systems, is described. Distribution of spray solution was less variable with the new sprayer than with the micro‐plot sprayer previously used, Variations in spray distribution due to uneven propulsion of the sprayer by hand were less than that due to the nozzles and contributed little to the overall coefficient of variation. A nozzle‐testing table did not predict the spray distribution achieved by the sprayer.

Elaboration d'un nouveau type de pulvérisateur pour petites parcelles et prévisions de ses possibilityés au champ.

Les auteurs decrivént un pulvérisateur destinéà I'application d'herbicides sur des parcelles de 1 m2, au champ, d'une manière très proche des systèmes de pulvérisation conventionnels. La distribution de la bouillie herbicide a été moins variableavec lenouveau pulvérisateurqu'aveccelui précédemment utilisé pour les micro‐parcelles. Les variations dans la distribution du liquide pulvérisé provoquées par les irrégularitiés dc la propulsion manuelle du pulvérisateur, onl été inférieures à celles provenant des buses et n'ont contribué que pour une faible pan au coefficient global de variation. Une table d'essai des buses n'a pas permis de prtvoir la distribution de la pulvérisation effeciuée par le pulvérisateur.

Entwickhtng eines neuen Kleinpariellen‐Spritzgeräts und einige Anmerkungen ztim Feldeinsatz

Eswirdein Herbizid‐Spritzgerät fur 1 m2 grosse Feldparzellen beschrieben, mit dem die Applikation ahnlich wie mit herkömmlichen Spritzen durchgefiührl wird. Die Verteilung der Spritzflüssigkeit war mit dem neuen Gerät einheitlicher als mit dem früher verwendeten Kleinparzellcn‐Spritzgerät. Die Schwankungen in der Brüheverteilung, bedingt durch ungleichmässigen Handbetrleb, waren geringer als die durch die Däsen verursachten und trugen wenig zum gesam‐ten Slreuungskoefflzienten bei. Die Verteilung der Spritz‐brühe stimmte nicht mit den Daten aus einer Düsenprüftabelle überein.
Suppression of Cyperus rotundus L. in carrots with night applications of nitrofen or herbicidal oil*
Authors: WILLIAM R. D. , WARREN G. F.
Published: July 2006

Summary: Résumé: Zusammenfassung

Selective control or suppression of Cyperus rotundus L. in carrot (Daucus carota L.) was investigated in Brazil using post‐emergence applications of nitrofen (2,4‐dichlorophenyl 4‐nitrophcnyl ether) or a herbicidal oil (11–7% aromatics). Night applications of nitrofen in water, nitrofen in the herbicidal oil and the herbicidal oil alone were more effective in suppressing the growth of C. rotundus foliage than day applications. Nitrofen and the herbicidal oil were, respectively, 50 and 30% more active in suppressing C. rotundus during the warm, wet season (October to March) than the cool, dry season (April to September) in Viçosa. Night applications of nitrofen (1, 2 and 4 kg/ha) in water and the herbicidal oil alone (100, 200 and 400 1/ha) suppressed C. rotundus by 60% or more, and resulted in similar carrot yields to the hand‐weeded control. Combinations of nitrofen in the herbicidal oil were more effective in suppressing C. rotundus than either herbicide applied alone, but the combinations tested were toxic to the carrots.

Elimination du Cyperus rotundus L. dans les cultures de carrottes au moyen d'applications nocturnes de nitrofène ou d'une huile herbicide..
Regeneration of blackberry (Rubus procerus P. J. Muell.) from root segments
Authors: Richardson R. G.
Published: July 2006

Temperatures from 13°C to 30°C had no significant effect on the formation of shoots on root segments of Rubus procerus P. J. Muell. Shoots were not produced at 8°C. Some new roots were produced on root segments at all temperatures between 8°C and 30°C, although significantly more (P= 0·05) roots were produced at 26°C. The polarity of the root system was maintained in root segments. More shoots were formed towards the basal end, i.e. nearest the crown, and more roots towards the apical end of the root segments.
Residues of atrazine, simazine, linuron and diuron after repeated annual applications in a peach orchard
Authors: MARRIAGE P. B. , SAIDAK W. J. , VON STRYK F. G.
Published: July 2006

Annual applications of the herbicides atrazine, simazine, linuron and diuron at 45 kg/ha were made to the same plots for 9 consecutive years from 1963 to 1971 in a peach (Prunus persica (L.) Batsch.) orchard located on sandy loam soil near Harrow, Ontario. Soil samples from these plots were collected in late October for the last 3 years (1969–1971) and trees were cut down in December, 1969. Herbicide residues were determined by bioassays based on the fresh and dry weight of oats (Avena sativa L.) and in one year results were confirmed by chemical analysis. Significant accumulation of herbicides was not observed. The maximum residue levels measured in October over the 3 years of sampling were 7′3 kg/ha for diuron, 3–8 kg/ha for linuron, 1–6 kg/ha for simazine and 04 kg/ha for atrazine in the top 15 cm of the soil profile. Simazine and atrazine showed a rapid decrease in amount after treatment but diuron and linuron were degraded more slowly. Measurable residues of all herbicides were confined to the upper 15 cm of the soil profile and the majority of herbicide remained in the 0–5‐cm soil layer. Oats were planted in the orchard plots from 1972 to 1974 to follow the disappearance of the herbicides. All herbicides caused highly significant yield decreases in 1972, atrazine causing the least (38%) and diuron the greatest (86%) reductions. Diuron reduced the yield of oats in 1973 and caused a highly significant decrease in the weight of young oat plants in 1974.