bluuebunny/crossref_metadata_2025 huggingface dataset:
Quelques aspects de la physiologie des radis (Raphanus sativus L.) traités par la simazine
Authors: GNANARETHINAM JOHN L.
Published: July 2006

l'influence de la simazine sur l'évolution de l'azote chez le radis (Raphanus sativus L.) a étéétudiée en considérant le métabolisme de l'azote total et la synthèse des proténes. Dans les racines et les pétioles, l'azote total a peu évolué alors qu'il augmente notablement dans les limbes vers les 5ème et 6ème jours après le traitement, diminue ensuite tout en restant supérieur au taux initial, puis se stabilise jusqu'à la mort de la plante. Les radis traités par la simazine absorbent plus d'azote que le témoin. l'étude de l'azote protéique, de l'azote organique soluble et de l'azote nitrique a montré que la simazine n'agissait pas sur la protéosynthèse.

Une expérience faite avec de l'azote marquée 15N a montré que la plante absorbe préférentiellement les nitrates.
Ultrastructural changes in leaf and needle segments treated with herbicides containing picloram
Authors: AYLING R.D.
Published: July 2006

The herbicide Tordon 50D (picloram+2,4‐D) affected the integrity of the nucleus and cell membranes in Pinus radiata needle segments and caused the swelling of internal chloro plast membranes and the eventual disintegration of the chloroplasts. Tordon 22K (picloram) only affected chloro plast structure.

Both herbicides had similar adverse effects on cell membranes and chloroplasts of Eucalyptus viminalis.
Observations on the influence of orchard soil management on simazine movement
Authors: ATKINSON D. , ALLEN J. G.
Published: July 2006

The concentration of simazine in surface soil was determined on two occasions at a number of sites in a 2‐year‐old apple orchard under either conventional herbicide strip or overall herbicide soil management. There was no evidence of simazine re‐distribution in conventional herbicide strips. With overall herbicide management there was evidence of the movement of simazine from much of the area of the orchard and its accumulation in either small erosion channels or deposition areas. This was prevented by a thin litter of straw spread over the soil surface.
Untersuchungen über Sonchus arvensis L. III, Metabolismus von MCPA
Authors: FYKSE HALDOR
Published: July 2006

14C‐MCPA wurde beim Auspflanzen der Wurzelstückchen, und wenn die Pflanzen 3 cm, 5–7 cm und 12–15 cm lange Blätter entwickelt hatten, in die Wurzeln von Sonchus arvensis L. injiziert. Nach Extraktion mit 70%‐igem Äthanol und Trennung auf Dünnschichtplatten konnten durch Scanning drei hier als 1, 2 und 3 genannte Komponenten nachgewiesen werden. Komponente 2 chromatographierte wie MCPA und bestand aller Wahrscheinlichkeit nach aus dem nichtmetabolisierten Rest der injizierten Substanz. Komponente 3 wurde schneller als Komponente 1 gebildet, aber beide Komponenten wurden unter Einfluss von 1N HCl oder 1N NaOH+Wärme zur Komponente 2 (MCPA) verwandelt. Komponente 3 unterschied sich wieder von Komponente 1 durch ihre höhere Umwandlungsgeschwindingskeit.

Der Metabolismus von MCPA verlief um so schneller, je älter die Pflanzen waren, und war in Mutterwurzeln rascher als in Tochterwurzeln und Blättern. Dormante Wurzeln zeigten eine Fähigkeit MCPA zu metabolisieren auf, die wenigstens nicht geringer als bei nicht‐dormanten Wurzeln war. Weiter verlief der Metabolismus schneller bei 23° als bei 70.

Abspaltung von 14CO2 war ein langsamer Prozess, und nach 4 Tagen machte die Aktivität des ausgeschiedenen 14CO2 nur 1,3% der Gesamtaktivität aus.

In Biotesten mit Raphanus sativus L. als Testpflanze, zeigte Komponente 3 eine entsprechende Phytotoxizität wie Komponente 2 (MCPA) auf, während die stabilere Komponente 1 sehr wenig phytotoxisch war.
The effect of soil aggregate size and water content on herbicide concentration in soil water
Authors: HANCE R. J.
Published: July 2006

Suspensions of wettable powders of metribuzin and simazine were sprayed onto samples of two soils of two particle size grades, > 2.5 mm and <0.5 mm. The soils were either air‐dry or at a water content of 12%. After either 1 h or 1 week, water was added to give a soil to water ratio of 1:1. Samples of solution were analysed after 1, 24 and 48 h.

With metribuzin the intial concentration for both soils after wetting was greater from the >2.5 mm samples than the <0.5 mm samples, following application to dry soil, but by 48 h the differences were negligible. With simazine WRO soil did not show this effect at all and with Kirton soil only small differences were seen. If the soil was wet at the time of application, particle size had no effect except with simazine in Kirton soil.

Generally metribuzin concentrations were higher after application to wet than to dry soils for at least 24 h after wetting whereas simazine concentrations were higher from initially dry soils and the differences had virtually disappeared 24 h after wetting.

With the WRO soil herbicide concentrations in soil water were higher if the soil was wetted 1 h after spraying than if left for 1 week but the differences rarely persisted for 48 h. No such trend was observed with Kirton soil.

It is concluded that the differences observed in these experiments could be responsible for variations in the performance of soil‐applied herbicides.
Factors affecting seed germination ofEchium plantagineumL. andTrifolium subterraneumL.
Authors: PIGGIN C. M.
Published: July 2006

Echium plantagineumL. is a widespread, persistent, and often dominant volunteer species in southern Australia. This paper describes laboratory and field experiments investigating seed germination in E. plantagineum and a commonly associated species, Trifolium subterraneum L. In the laboratory, E. plantagineum germination was favoured by relatively high temperatures, and the seed showed considerable innate and temperature‐enforced dormancy. In the field, this dormancy appeared to prevent some germination in response to rainfalls immediately after seed formation, and permitted sporadic germination during summer and autumn in subsequent years. In 1972 and 1974, both species emerged well in autumn whilst E. plantagineum was favoured in summer and T. subterraneum was favoured in winter. No seedlings emerged in spring. Emergence appeared to be controlled primarily by moisture availability and temperature but also was affected by cultivation and removal of soil‐surface litter. The results of these seed germination studies show that E. plantagineum is well adapted to persist in a Mediterranean‐type climate, and will be favoured in years with early seasonal breaks. T. subterraneum is likely to be favoured with later breaks.
Weed competition in spring‐planted strawberries
Authors: LAWSON H. M. , WISEMAN J. S.
Published: July 2006

Annual weeds germinating after planting strawberry (Fragaria chiloensis (L.) Duch. cv. Cambridge Favourite) in late March had no effect on crop growth if removed by late May. Dense weed cover thereafter severely inhibited stolon growth, virtually eliminating it if allowed to remain beyond mid‐August. Shading by weeds inhibited leaf production and caused etiolation of existing leaves. New leaves appeared shortly after weed removal and few plants died unless weed cover persisted for most of the growing season. Further weed germination was allowed on some plots. Although not removed until late autumn, these weeds only had adverse effects on crop growth where initial weeding had occurred before mid‐June.

In one experiment, delaying weed removal until 6 July, 31 August or 2 November in the first year reduced fruit yield in the second (weed‐free) year by 34%, 54% and 67% respectively. In a later experiment, competition from weeds until July or later in the first growing season gave fruit yields similar to those in the first experiment, but totally weed‐free plots and those kept clean after weeding in mid‐June produced less fruit than plots which remained weedy between mid‐June and mid‐August. It is suggested that competition from uncontrolled stolon growth in this experiment severely inhibited crown and hence truss production on plots which did not suffer weed competition. Unless left untouched until early September, weeds had less adverse effect on truss production than the stolons which they displaced.

The results are interpreted in relation to improving the efficiency of weed control techniques.
Quantitativer Biotest zur Bestimmung von Photosynthesehemmern im Boden
Authors: PESTEMER W.
Published: July 2006

Ein quantitativer Biotest zum Nachweis von Photosynthese‐hemmern in Böden, Hydrokultur und Zellstoffwatte wird beschrieben. Als Testpflanze erwies sich Gartenkresse (Lepidium sativum L.) als sehr gut brauchbar. Anhand von Beispielen mit Monolinuron und Methabenzthiazuron werden einige Anwendungsmöglichkeiten Bestimmung der herbiziden Wirksamkeit, Pflanzenverfügbarkeit und Ermittlung der ED5o‐Werte in verschiedenen Bden gegeben. Für Monolinuron z.B. konnten Konzentrationen von <0.04 ppm quiintitativ nachgewiesen werden.

Photosynthesehemmerzeigen auf Keimung und Wachstum der Kressesämlinge erst nach 5 Tagen einen Effekt; denn eine Beeinträchtigung des Wachstums tritt erst dann ein, wenn die Reservestoffe des Endosperms aufgebraucht sind. Da her wurden die Reservestoffe in den Kressekeimlingen im Dunkelkeimversuch ermittelt und von alien Ergebnissen abgezogen, um ausschlieBlich die gebildete Trockenmasse bei Herbizideinwirkung zu erfassen.
Relationships between substituted urea herbicides and soil urease activity
Authors: CERVELLI STEFANO , NANNIPIERI PAOLO , GIOVANNINI GIACOMO , PERNA AMALIA
Published: July 2006

Fenuron, monuron, diuron, siduron, linuron and neburon were tested for their inhibition of soil urease activity in order to investigate relationships between fertilizers and herbicides.

The inhibition of urea hydrolysis in the selected soils was 10–33% for fenuron, 10–39% for monuron, 10–35% for diuron, 8–38% for siduron, 9–36% for linuron and 12–30% for neburon. In the field greater effects might be expected since the fertilizer/herbicide ratio would be lower than the one considered here.

Some agronomic aspects of the relationship between fertilizers and herbicides are discussed.
Effects from simulated rainfall on shoot‐zone uptake of herbicides
Authors: WALKER A.
Published: July 2006

In glasshouse experiments, atrazine, simazine, lenacil and linuron applied to the soil surface were phytotoxic to turnip seedlings which had emerged from a depth of 1–5 cm when 3 mm artificial rainfall was applied at the time of seedling emergence or shortly afterwards. When rainfall was applied on 2 or 3 consecutive days, the herbicides were in general more phytotoxic. As the delay between emergence and commencement of surface watering increased, however, the response of the seedlings decreased.

Studies with [14C]‐atrazine showed that at emergence the seedlings contained a small amount of herbicide which increased considerably with surface watering. Relatively high concentrations were attained when rainfall was applied while the seedlings were small, but as the interval between seedling emergence and rainfall increased, the same uptake resulted in lower shoot concentrations, Atrazine extraction from the soil showed little movement from the surface 1.0 cm, suggesting uptake via the stem. The observed responses of the other three herbicides are explained by assuming the same pattern of uptake as that recorded for atrazine.
Asulam mixtures for weed control in flax
Authors: CHOW P. N. P.
Published: July 2006

Five field experiments were conducted from 1972 to 1975 to evaluate weed control in flax (Linum usitatissimum L.) using post‐emergence treatments of asulam [methyl (4‐aminobenzenesulphonyl) carbamatel alone and in combination with other herbicides. The 14C‐asulam absorption by leaf segments and roots of glasshouse grown wild oats (Avena fatua L.) was also investigated. Asulam at 1.12 kg/ha gave good wild oat control and acceptable control of green foxtail (Setaria viridis (L.) Beauv.). However, wild oat control was poorer when asulam was combined with other herbicides: on a 3‐year average, as compared with asulam alone at equal rates, the asulam+MCPA mixture resulted in a greater antagonism and a significant 6% reduction in flax seed yield, whereas the asulam+bromoxynil/MCPA mixture gave the least antagonistic effect, improved broadleaf weed control and increased yield by 13%. In mixtures, the potassium salt of MCPA was more compatible with asulam for weed control than the amine form. Both leaf segments and roots of wild oats absorbed and distributed less 14C‐asulam from solutions containing MCPA than from those containing bromoxynil or bromoxynil/MCPA.
Growth of seedlings of Agropyron repens L. Beauv. and Agrostis gigantea Roth. in wheat and barley: effect of time of emergence, nitrogen supply and cereal seed rate
Authors: WIlLLIAMS E. D.
Published: July 2006

As part of a programme of work evaluating the role of seeds in regenerating or initiating infestations of Agropyron repens and Agrostis gigantea, the growth of the weeds was analysed in cereal crops in two experiments. The first experiment investigated the effects of time of planting the weed seedlings (simulating different times of emergence), nitrogen supply and cereal seed rate in winter wheat and the second, the same factors in spring wheat and spring barley.

In winter wheat, delaying planting of the weeds from autumn until spring greatly decreased shoot growth and almost completely prevented rhizome formation. Nitrogen fertilizer increased the weight of shoots of both species planted at both times but whereas it increased the amount of rhizome produced by Agropyron it decreased that of Agrostis. Without nitrogen Agrostis had twice as much rhizome as Agropyron but with nitrogen Agropyron had twice as much as Agrostis. Decreasing the cereal seed rate had little effect on rhizome weight when nitrogen was not given but it allowed twice as much rhizome to be produced when it was supplied. However, more longer rhizomes were formed at the smaller than at the larger seed rate with both amounts of nitrogen.

In spring cereals, late planting decreased the shoot growth of Agrostis more than that of Agropyron, and of Agropyron in barley more than in wheat, especially at the smaller seed rate. Nitrogen increased shoot weight of Agropyron in wheat but had little effect in barley; it decreased that of Agrostis in barley. On average, rhizome growth was decreased by nitrogen, by increasing the seed rate and by delaying planting. Agropyron rhizomes were heavier in wheat than in barley but those of Agrostis were heavier in barley than in wheat. Agropyron produced most rhizome in thinlysown wheat given nitrogen, but Agrostis most in thinlysown barley without nitrogen. The two treatments had an equal number of rhizomes longer than 100 cm.

The agricultural significance of the interaction of the various treatments is briefly discussed.
Competition from weeds and their control in direct‐seeded rice
Authors: SHARMA H.C. , SINGH H.B. , FRIESEN G.H.
Published: July 2006

In direct‐seeded upland rice (Oryza sativa L.) yield reductions due to weed competition ranged from 42 to 65% in field experiments conducted in eastern Utter Pradash, India. The most critical period, when crop losses due to weed competition were most severe, ranged from 10 to 20 days after emergence. Yields generally continued to increase, however, as the length of the weed‐free period increased. The weed flora consisted of various grasses, sedges and broadleaved species. The most effective herbicide treatment evaluated was a pre‐emergence application of alachlor followed by a post‐emergence application of propanil or one mechanical weeding.
The adsorption and degradation of glyphosate in five Hawaiian sugarcane soils*
Authors: NOMURA N.S. , HILTON H.W.
Published: July 2006

The rate of aerobic evolution of 14CO2 from 14C‐glyphosate labelled in the methylphosphonyl carbon, varied 100‐fold within a group of five Hawaiian sugarcane soils. The rate depended inversely on the degree of soil binding, probably associated with the phosphonic acid moiety, and to a less certain extent on soil pH and soil organic matter. After an initial rapid degradation, the rate of 14CO2 evolution in three soils reached a constant at 16–21 days which continued to the 60‐day termination. The other two soils showed a continually decreasing rate throughout. Two soils released over 50% of the labelled carbon in 60 days, a third released 35%, while the remaining soils released 1.2 and 0.8% respectively.

Labelled carbon in the soils after 60 days consisted of glyphosate and one metabolite, aminomethyl‐phosphonic acid, with glyphosate predominating in high fixing soils. The 14C could be extracted almost completely with NaOH solution, and remained mainly in solution after acidification.
Effect of trickle irrigation on soil‐applied herbicides*
Authors: KOREN E. , SHLEVIN E.
Published: July 2006

The effect of trickle irrigation on the activity, leaching and distribution in the soil of herbicides, was studied in a model specially constructed for simulating trickle irrigation in the field, and also under field conditions.

The pattern of movement of a soil‐applied herbicide in the soil under trickle irrigation paralleled, to some extent, that of the trickle water itself, but total herbicide movement was less than that of the water. Both water and herbicide distribution in the soil formed the shape of a hemisphere or cone under the trickle nozzle, the exact shape of which was determined by the soil characteristics (a narrow cone in a light soil and a wide cone in a heavy soil); cone size was determined by the amount of trickle water.

Bioassays with susceptible test plants showed that effective weed control could be expected with either simazine or GS‐14259 (2‐t‐butylamino‐4‐ethylamino‐6‐methoxy‐s‐triazine =‘Caragard') only in the areas wetted by the trickle nozzle.

The results showed that the pattern of distribution in the soil of simazine and GS‐14259 was similar, but there were quantitative differences in their final spread.
Persistence of terbacil and trifluralin under different soil and climatic conditions
Authors: RAHMAN A.
Published: July 2006

Soil samples were collected from forty‐three field trials conducted on ten soil types to investigate the residual activity of terbacil and trifluralin at the end of the cropping season, approximately 6 months after application. The soil was bioassayed in a glasshouse using soya beans and German millet for terbacil and trifluralin respectively. At 1 kg/ha terbacil phytotoxic residues occurred in a majority of the trials, while at 2 kg/ha such a carry‐over could be found in every case. Trifluralin doses of up to 1 kg/ha did not persist in toxic amounts in most soils, while application of 2 kg/ha showed residual activity in 74% of the trials and application of 4 kg/ha killed German millet in all instances. Results are also presented from the time‐rate dissipation studies conducted on both herbicides by assaying soil samples collected at monthly intervals.

Both organic matter and clay content of the trial sites affected the persistence of terbacil, while trifluralin residues were influenced only by the soil organic matter content. Trial sites receiving high rainfall showed considerably less residues of terbacil, but the persistence of trifluralin was not affected by rainfall to any appreciable extent.
An agro‐economic survey of the weeds and weeding practices in cassava (Manihot esculenta Crantz) in Colombia
Authors: DOLL JERRY , PINSTRUPANDERSEN PER , DÍAZ RAFAEL
Published: July 2006

A survey of weeds and weeding practices was carried out by a team of agricultural economists and agronomists on 283 farms in five Cassava growing regions of Colombia at three times during a cropping season.

Seventy‐one to 78% of all weed species present were broadleaved species. As cassava grew older, grass species were present to a greater and sedge species to a lesser relative frequency. Surprisingly Pteridiumaquilinum (L.) Kuhn was the most frequently listed species and Bidens pilosa L. and Cyperus rotundus L. were other frequent problems. Regional variations in the most frequently encountered species were found but several of the weeds were common to many zones. The most frequently encountered species did not usually have the highest plant populations. Most of the annual grasses, sedges and broadleaf weeds found can be controlled by currently recommended herbicides for cassava but further research is needed on Imperata cylindrica (L) Beauv., Melinis minutlftora Beauv., P. aquilinum and Sida spp.

The average number of manual weedings was 3.3 per crop, occupying 48 man‐days/ha which is 50% of the total labor requirements for cassava production, and more than one‐third of the total costs. Reasons for not using herbicides were (1) relative costs of herbicides and labor. (2) lack of information, (3) lack of capital, (4) right herbicides were not available, and (5) herbicides were not available in small packages.

This survey has usefully identified new field problems and has suggested further research programs to solve them.
Alachlor placement in the soil as related to phytotoxicity to maize (Zea mays L.) seedlings*
Authors: NARSAIAH D. BALA , HARVEY R. G.
Published: July 2006

Growth chamber studies were conducted to investigate the effects of alachor (2‐choloro‐2′,6′‐diethyl‐N‐ (methoxymethyl) acetanilide) on emerging seedlings of maize (Zea mays L.) planted 2.5 and 8.0 cm deep in a Plano silt loam soil. Alachlor was localized in the shoot zone, in the root zone, and in the shoot and root zones. Four days after emergence, seedlings were harvested and total shoot and root lengths used as measures of herbicidal effectiveness. The herbicide applied at a rate of 2.5 kg/ha caused a severe reduction in seedling height when placed in the shoot zone of seeds planted at the shallow depth. This injury was prevented when seeds were planted at the deeper level. When alachlor was placed in the root zone, there was no inhibition of shoot growth. When both shoot and root zones were exposed to the herbicide, severe growth inhibition again occurred. Roots were less sensitive to alachlor. A simple technique involving use of sand and activated charcoal barriers to effectively separate the shoot and root zones is described.
Zum Metabolismus von Phenylharnstoff‐Herbiziden VII. Metabolismusaufklärung und Bilanzierung des Verbleibs von Buturon‐14C nach Anwendung bei Winterweizen.
Authors: SCHUPHAN I. , EBING W.
Published: July 2006

Die radioaktive Bitanz zum Erntezcitpunkt ergab, daβ 89.1% der eingesetzten Radioaktivität wiedergefunden wurden. Davon waren 50.1% im Boden, 12.6% im Stroh, 3.7% in den Wurzeln, 1.3% in den Körnern nachweisbar. 16.2% wurden zu radioaktivem Kohlendioxid umgewandelt und fanden sich gasförmig oder im Kondenswasser niedergeschlagen. Die Radioaktivität im Pflanzenmaterial lag nur zu etwa 50% in extra hierbarer Form vor. In diesem Aktivitätsanteil bildeten stark polare Metaboliten die Hauptmenge, während die vier weniger polaren, identifizierten Buturonmetaboliten nur bis zu je 12% erreichten.
The influence of plant age on the movement of 2,4‐D and assimilates in wheat
Authors: OLUNUGA B. A. , LOVELL P. H. , SAGAR G. R.
Published: July 2006

A quantitative study of the movement of 2,4‐D and assimilates was made using radiocarbon‐labelled materials. At the two‐three leaf stage of wheat (cv Koga II) 2,4‐D moved more slowly than assimilates, but the patterns of movement were very similar. At the five‐six leaf stage of the cereal there were differences between 2,4‐D and assimilates in the patterns of distribution from leaf 1 and from a leaf on a tiller. In both cases relatively less 2,4‐D moved into roots than would have been predicted from knowledge of assimilate movement. Total amounts of 2,4‐D reaching the roots did not differ significantly between growth stages but due to root growth, the concentration of radio‐activity in the roots fell.
Evolution of resistance to simazine in Senecio vulgaris L.
Authors: HOLLIDAY R. J. , PUTWAIN P. D.
Published: July 2006

Fruits were collected from populations of S. vulgaris growing on commercial fruit farms and progenies were tested for susceptibility to simazine. The five least susceptible populations, which originated from sites where simazine had been applied annually for periods ranging from six to ten years, were subjected to two generations of artificial selection for simazine resistance. Two control populations which originated from unsprayed sites were treated similarly.

One population originating from Malpas, Cheshire showed a significant response to selection. The simazine resistance of the other six populations was not improved by artificial selection. Selected progenies of the Malpas population were completely unaffected by simazine at 2.8 kg ha−1.

The potential for evolution of resistance to simazine in S. vulgaris is discussed and the effects of ecological and genetic factors on the rate of evolution are assessed.
Uptake patterns of soil‐applied 45Ca and 32P in some legume species as influenced by differential trifluralin placement
Authors: O'DONOVAN J. T. , PRENDEVILLE G. N.
Published: July 2006

The effect of localized placement of trifluralin on uptake patterns of soil‐applied 45Ca in vetch (Vicia sativa L.), pea (Pisum sativum L.) and soybean (Glycine max) and 32P in vetch and pea was investigated in two soil zones in the roots and in the shoot zone before and after plant emergence.

When trifluralin was in the upper root zone severe inhibition of lateral roots occurred as well as a marked decrease in uptake of 45Ca and 32P from this zone. Root growth in the lower zone was unaffected, but uptake of 45Ca and 32P was slightly reduced. Compensatory adventitious root growth as well as a marked increase in uptake of 45Ca and 32P occurred in the shoot zone. Neither root growth nor uptake of 45Ca or 32P in the upper root zone were affected by the presence of trifluralin in the lower root region. When trifluralin was placed in the shoot zone after plant emergence, adven‐titious roots on the shoots were inhibited and uptake of 45Ca and 32P was reduced.
Effect of aggregate size on leaching of herbicide in soil columns
Authors: DEKKERS W. A. , BARBERÁ E.
Published: July 2006

In a column experiment with dry aggregated soils, the effect of aggregate size on leaching of metribuzin from the upper soil layer (2.5 cm) was studied.

The penetration of the herbicide was less than predicted by the equilibrium retardation factor. The penetration was less for large than for smalt aggregates due to kinetic effects induced by the aggregates. These kinetic effects overruled the effect of adsorption.

Although the mean herbicide penetration was limited, part of the herbicide moved freely with the water as the herbicide was found throughout the column and in the leachate.
Mixtures of picloram and 2,4,5‐T for the control of blackberry (Rubus fruticosus L. agg.)
Authors: AMOR R. L. , HARRIS R. V.
Published: July 2006

The effectiveness of‘Tordon 50‐d’(5% a.i. picloram plus 20% a.i. 2,4‐D both as the triisopropanolamine salts) and various mixtures of 2,4,5‐T and picloram were tested for the control of blackberry (Rubus fruticosus L. agg.) in Victoria, Australia.

A high correlation was obtained between the % reduction in live canes and the % kill of crowns 13 months after Rubus procerus P.J. Muell. thickets were sprayed with 2,4,5‐T or‘Tordon 50‐d'. Counting the number of live canes is, therefore, a convenient method of comparing the efficacy of these herbicides for the control of blackberry.

‘Tordon 50‐d’was generally more effective than 2,4,5‐T but stimulation of suckering from roots was recorded at one site when low rates of‘Tordon 50‐d’were used. It was necessary to add high dose rates of‘Tordon 50‐d’to 2,4,5‐T before there were worthwhile improvements in weed control.‘Tordon 5–20’(5% a.i. picloram as triisopropanolamine salt plus 20% 2,4,5‐T as the ethyl hexyl ester) was only slightly more effective in controlling blackberry than‘Tordon 50‐d'. The cost and soil residue problems associated with picloram should limit its use as an additive to 2,4,5‐T for the control of blackberry in Australia.
Influence de la matière organique et de la teneur en eau du sol sur les phenomenes de sorption de l'aniline
Authors: MOREALE A. , GALLEZ A. , VAN BLADEL R.
Published: July 2006

L'adsorption d'aniline est directement reliée à la teneur en matière organique et cette adsorption semble principalement dépendrede la fraction acides humiques des sols.

L'effet compétitif de l'eau du sol pour l'adsorption d'aniline a été mis en évidence. l'influence de la concentration des suspensions colloidales sur le phénoméne d'adsorption montre qu'en milieu naturel les quantités résiduelles d'aniline dans la solution du sol seraient à l'état de traces.

Dans tous les cas, la désorption šaccompagne d'un phénomène d'hystérésis assez prononcé mais les solutions salines (CaCl2) manifestent cependant un plus grand pouvoir de déplacement de l'aniline adsorbée.
Preliminary experiments on utilization of water hyacinth by grass carp
Authors: RIECHERT CHRISTOPH , TREDE RAINER
Published: July 2006

Preliminary aquarium experiments have been carried out on the feeding of water hyacinth (Eichhornia crassipes (Mart.) Solms) to grass carp (Ctenopharyngodon idella Via.). Eleven months old fish weighing 38 to 104 g were fed for 50 days exclusively on E. crassipes. Roots and leaves were accepted readily but the swollen petioles reluctantly. The fish developed well, producing 6.5g live weight from 10g dry matter of E. crassipes. The results suggest the possible use of grass carp for the solution of E. crassipes problems. Further extensive experiments are required in the field, however, to determine the influence of grass carp on the ecology of waters infested with this weed.
Effect of concentration on absorption and translocation of 2,4,5‐T in blackberry (Rubus procerus P. J. Muell.)
Authors: RICHARDSON R.G. , GRANT A.R.
Published: July 2006

Radioactive 2,4,5‐T was applied to the leaves of small Rubus precerus (P. J. Muell.) plants grown in pots in the glasshouse in amounts ranging from 24 μg to 55.8 μg per leaf. The amount of 2,4,5‐T absorbed and translocated was measured 6h and 24h later. The herbicide was translocated throughout the plant within 6h and the concentration in the various plant parts increased between 6h and 24h.

More 2,4,5‐T was absorbed at high concentrations than at low concentrations although the percentage absorbed in 24h decreased from 13% to 6% as the concentration was increased Translocation of 2,4,5‐T‐1‐14C was variable, although the amount translocated inereased as the amount applied was increased, and was closely correlated to the amount of herbicide absorbed by the leaves.
The effect of atrazine, cyanazine and cyprazine on photosynthesis and growth of nine grasses*
Authors: JENSEN K. I. N. , STEPHENSON G. R. , HUNT L. A. , BANDEEN J. D.
Published: July 2006

A semi‐open circuit system for measuring changes in net CO2 exchange (NCE) in single leaves of intact grasses following herbicide treatment is described and evaluated. There were significant differences in levels of inhibition and subsequent recovery of NCE in maize and eight weedy panicoid grasses following limited root uptake of atrazine (2‐chloro‐4‐ethyl‐amino‐6‐isopropylamino‐1,3,5‐triazine). cyanazine [2‐chloro‐4‐(1‐cyano‐1‐methylethylamino)‐6‐ethylamino‐1,3,5‐triazine] and cyprazine (2‐chloro‐4‐cyclopropylamino‐6‐isopropyl‐amino‐1,3.5‐triazine). Rate of NCE recovery was positively correlated (P = 0.05) with growth of seedlings in nutrient solution containing the herbicides. Rates of NCE recovery >0.9 mg CO2 per dm2 per h/h reflected rapid rates of herbicide detoxification in the leaves and a significant tolerance to preplant incorporated and postemergence applications of atra‐zine, cyanazine and cyprazine. In contrast, some species, e.g. large crabgrass [Digitaria sanguinalis (L.) Scop.] and proso millet (Panicum miliaceum L.) treated with cyanazine demonstrated considerable tolerance to these treatments in spite of low NCE recovery rates indicating that factors other than foliar detoxification may play an important role in the tolerance of some grasses to 2‐chloro‐ 1,3,5‐triazine herbicides.
Differential atrazine interference with the Hill reaction of isolated chloroplasts from Chenopodium album L. biotypes
Authors: MACHADO V. SOUZA , BANDEEN J. D. , STEPHENSON G. R. , JENSEN K. I. N.
Published: July 2006

Atrazine [2‐chloro‐4‐(ethylaminol‐6‐(isopropyl‐amino)‐s‐triazine] resistant biotypes of lamb's quarters (Chenopodium athum L) were reported in the maize growing areas of Ontario, where the herbicide had been used fur a number of years. Field samples from four locations proved tolerant to higber than recommended rates of atrazine in controlled environment screening trials. A resistant biotype was not killed with up to 40 kg/ha atrazine. Diuron at 5 x10‐5 M inhibited the Hill reaction with isolated chloroplasts of resisiant and susceptible biotypes of lamb's‐quarters. However, with 10‐4 M atrazine, the photochemical activity was inhibited in chloroplasts isolated from the susceptible biotype but not in chloroplasts from the resisiant biotype. With maize chloroplasts, inhibition with 10‐4 M atrazine was the same as with the susceptible biotype of lamb's‐quarters. These studies suggested that a new mechanism of intraspecific resistance in lamb's quarters to atrazine was involved, other than differences in uptake, translocation and metabolism reported with interspecific comparisons involving the s‐triazines and other herbicides, It was also concluded that atrazine and diuron did not have precisely the same mechanism of action as photosynthetic inhibitors with lamb's‐quarters, and that external and or internal structure or function of chloroplasts in relation to atrazine inhibition can vary significantly even in biotypes of the same species.
Degradation of Nitralin by Rhizoctonia solani
Authors: CAMPER N.D. , ELLERS KATHRYN L.
Published: July 2006

Summary: Résumé: Zusammenfassung

Degradation studies of nitralin [4‐(methylsulfonyl)‐2.6‐dinitro‐N.N‐dipropylaniline] were performed with pure cultures of Rhizactoma solani Kühn. Czapek Dos Broth was selected as the growth medium and contained no components which interfered with extraction and subsequent TLC analysis. Ten to I I degradation products were detected after 14 to 21 days incubation at 33°C, The nonpolar fraction (ethyl acetate exlraclahkl contained at least nine compounds visible on TLC plales. Only one product other than the parent nitralin was identified the monoalkylated derivate. 4‐(meihylsulfonyl)‐2.6‐dinitro‐N‐pro‐pylanilinc. After 21 days approximately 10% of the original nitralin could be detected. The aqueous phase (after ethyl ace‐late extraction) was concentrated, placed on a Sephadex G10 column and separated into at leasi two products. No 14CO2 evolution was detected from 14C‐ring labeled nitralin.

Dégradation de la nilralinepar Rhizoclonia solani

Dcs ètudes de dégradation de la nitraline [4‐(méthylsulfonyl)‐2,6‐dinitro‐N,N‐dipropilanihne) ont été effectuées avec des cultures pures de Rhizurtvnia solani Kühn. Le milieu de culture de Czapek. Dox, Broth, a été choisi; il ne contenait pas de composés qui auraient pu interférer a vet I'extraction el avec l'analyse chromalographique en couchc mince ulténeure. Dtx à 11 produits de dégradation ont été décelés après 14 à 21 jours d'incubation à 33 C, La fraction non polaire (extructible par l'acétate d'éthyle) contenait iu minimum 9 composés visibles sur les chromatogrammes Un produit seulement. autre que la nitralinc apparentée. a été identific. le dèrivé monoalkylé. 4‐(methylsulfonyl)‐2.6‐dinilro‐N‐propylflniline, Aprés 2l jours. 10% environ de la nitralinc origmale avait pu ètre décelée. La phase aqueuse (aprés extraction à l'acétate d'ethyle) a été con‐centrée. placée sur une colonne de Scphadex G10 el séparée en deux produits au moins. II n'a pas été décelé d'èevolution du 14CO2 provenant du cycle marqué au 14C de la nitraline.

Abhau van Nitrulirt durch Rhizoctonia solani

Es wurden Abbaustudien mit Nitralin unter Verwendung von Rcinkulturen von Rhizoctonia solani Kühn durchgeführt. Also Wuchsmedmm wurde Czapek Dox Broth verwendet. das keine Substanzen enthielt. die die Extraktion und die daraffogende dünnschichtchromatographische Analyse störten. Nach einer Inkuhationszeit von 14 bis 21 Tagen nei einer Temperatur von 13°C. fturden 10 bis 11 Abbauprodukte nachgewiesen. Die nicht‐polare Fraktion (extrahierbar mil Äthylacetal) enthielt mindestens 9 auf Dünnschichtplatten sichtbare Verbindungen Eine Substanz wurde identifiziert—das monoalkylierte Derivat 4‐(Methylsulfonyl)‐2.6‐dinitro‐N‐propylanilin Nach 21 Tagen konnten noch ungefähr 10% des ursprünglichen Nitralins nach. gewiesen werden. Die wässrige Phase (nach Extraktion mit Äthylacetat) wurde eingeengt und auf einer Sephadex G 10 Säule in mindestens 2 Verbindungen aufgetrennt. Aus l4C‐ring‐markiertem Nitralin konnte keine 14CO2 ‐Freisetzung nachge‐wiesen werden.
Miniaturized methods for testing the toxicity of pesticides to microorganisms
Authors: COOPER S. L. , WINGFIELD G. I. , La WLEY R. , GREAVES M. P
Published: July 2006

Summary: Résumé: Zusammenfassung

A minialurized method of determining the toxicity of pesticides to large numbers or soil mitroorganisms is described. Bacteria. actinomycetes, yeasts, fungi and algae can be used as test organisms. A modification of the method allows determination of minimum inhibitory concentrations of pesticides to specific microorganisms. Some results obtained with herbicides are presented.

Microméthodex pour éprauver la toxicité des pesticides vis‐á‐vis des micro‐organismes

Une micromethode pour determiner la toxicité des pesticides vis‐á‐vis de nombreux micro‐organismes du sol est décrite. Des bactéries. des actinomycetes, des levures. des champignons et des algues peuvent ëtre utilisés comme organismes‐tesis. Une modifitation de la méthode permel les determinations des concentrations minimales inhibitrices des pesticides vis‐á‐vis des micro‐organismes specifiques. Quelques resultats obtenus avec des herbicides sont présentés.

Miniaturisierte Methoden zur Prüf'ung der Toxizitüt von Pflan‐ zenhehandlumgsmit teln auf Mikraorganismen

Es wird einc miniaturisierte Methode zur BestimmungderToxi‐ zität von Pfianzenbehandlungsmitteln für groβe Zablen von Bodenmikroorganismen beschrieben, Als Testorganismen können Bakterien. Actinomyceten. Hefen, Pilze und Algen benutzi werden. Eine Modifizierung der Methode gestattet die Bestimmung der Minimum‐Hemmkonzentration von Pflanzen‐ behandlungsmitteln auf spezielle Mikroorganismen. Einige Ergebnisse, die mit Herbiziden erarbeitel wurden. sind darge‐stellt.
Relative persistence of di‐and tri‐chlorophenoxyalkanoic acid herbicides in Saskatchewan soils
Authors: SMITH ALLAN E.
Published: July 2006

Summary: Résumé: Zusammenfassung

The persistence of 2,4‐D, 2,4‐DB, dichlorprop, 2,4,5‐T, and fenoprop at the 2 ppm level was studied in the laboratory on three prairie soils at 85% of field capacity and 20°C. Following extraction of the soils with aqueous acetonitrile containing acetic acid, the herbicidal acids remaining were analysed gas chromatographically.

Breakdown was rapid on all soils and the average half‐lives for 2,4‐D, 2,4‐DB, dichloroprop, 2,4,5‐T, and fenoprop were < 7, < 7, 10, 12, and 12 days respectively. Degradation on air‐dried soils (15% of field capacity) was negligible with over 85% of the applied herbicides being recoverable after incubation periods during which the herbicides remaining in the moist soils accounted for less than 30% of the original treatments.

Persistance relative des acides di et tri‐chlorophénoxy‐alkanoï‐ques herbicides dans des sols du Saskatchewan.

La persistance du 2,4‐D, du 2,4‐DB, du dichlorprop, du 2,4,5‐T et du fénoprop, à la concentration de 2 ppm, a étéétudiée au laboratorire, sur trois sols de prairie, a 85% de la capacité au champ et a 20°C. Après leur extraction des sols par l'acétonitrile aqueux contenant de l'acide acétique, les acides herbicides restants ont été analysés par chromatographie en phase gaseuse. La dégradation a été rapide pour tous les sols et les demi‐vies moyennes du 2,4‐D, du 2,4‐DB, du dichlorprop, du 2,4,5‐T, et du fénoprop ont été respectivement de <7, <7, 10, 12 et 12 jours. La dégradation sur des sols séchés a l'air (15% de la capacité au champ), a été négligeable, plus de 85% des quantités d'herbicides appliquées étant récupérables après des périodes d'incubation durant lesquelles les herbicides restant dans les sols humides ne représentaient plus que moins de 30% des quantités apportées à l'origine.

Relative Persistenz von Di‐und Trichlorphenoxyalkansäure‐Her‐biziden in Böden Saskatchewan

In Laborversuchen wurde die Persistenz von 2,4‐D, 2,4‐DB, Dichlorprop, 2,4,5‐T und Fenoprop in drei Prärieböden festgestellt. Die Versuche wurden bei 20°C, 85 % der Feldkapazität und einem anfänglichen Herbizidgehalt der Böden von 2 ppm

durchgeführt. Die Extraktion der Böden erfolgte mit wässerigem Acetonitril mit einem geringen Anteil an Essigsäure. Die Herbizide wurden gaschromatographisch nachgewiesen.

In allen Böden wurde ein schneller Abbau festgestellt. Die Halbwertszeiten betrugen für 2,4‐D, 2,4‐DB, Dichlorprop, 2,4,5‐T und Fenoprop < 7, < 7,10, 12 bzw. 12Tage. Der Abbau im lufttrockenen Boden (15% der Feldkapazität) war zu vernachlässigen. Hier waren noch mehr als 85% der ausgebrachten Herbizidmenge vorhanden, wenn in den feuchten Böden die Konzentration bereits weniger als 30% betrug.
A rapid sensitive bioassay for determination of paraquat and diquat in water
Authors: O'BRIEN MARY C. , PRENDEVILLE G.N.
Published: July 2006

Summary: Résumé: Zusammenfassung

The change in cell‐membrane permeability as indicated by leakage of electrolytes from treated fronds of Lemna minor was the criterion used to detect the presence of diquat and paraquat in solution. The minimum herbicide concentrations that could be detected ranged from 1.8 and 1.7 μg/ml diquat and paraquat cation respectively after 3 h treatment to 0.00018 and 0.000017 μg/ml after 72 h. Paraquat was more active than diquat in all treatments. Increase in cell‐membrane permeability occurred without the appearance of injury such as, chlorosis or bleaching of fronds. Light was necessary for these herbicides to alter cell‐membrane permeability, though a little herbicidal activity could be detected after 48 h in the dark at concentrations above 0.17μg/ml.

Un test biologique rapide et sensible pour la recherche du paraquat et du diquat dans l'eau

Des modifications de la perméabilité de la membrane cellulaire, révélées par la déperdition d'électrolytes à partir de frondes de Lemna minor, ont été utilisées comme critères pour révéler la prèsence de diquat et de paraquat dans des solutions. Les concentrations minimales d'herbicides qui ont pu être décelées se sont situées entre 1,8 μg/ml et 1,7 μg/ml des cations diquat et paraquat respectivement, apres 3 heures de traitement, jusquà 0,00018 et 0,000017 μg/ml après 72 heures. Le paraquat s'est montré plus actif que le diquat dans tous les traitements. Un accroissement de la perméabilité cellulaire s'est produit sans qu'il soit apparu de dégâts tels que la chlorose ou le blanchissement des frondes. La lumière a été nécessaire pour que ces herbicides altèrent la perméabilité de la membrane cellulaire, bien qu'une faible activité herbicide ait pu être décelée après 48 heures à l'obscurité, à des concentrations supérieures à 0,17 μg/ml.

Ein schneller und empindlicher Biotest für den Nachweis von Paraquat und Deiquat in Wasser

Veränderungen in der Permeabilität der Zellmembran in Form des Austretens von Elektrolyten aus behandelten Wedeln von Lemna minor wurden als Kriterium für den Nachweis von Deiquat und Paraquat in wässeriger Lösung benutzt. Die geringsten Herbizidkonzentrationen, die festgestellt werden konnten, lagen nach 3 h nach der Applikation bei 1,8 und 1,7 μg/ml Deiquatbzw. Paraquat‐Kation und nach 72 h bei 0,00018 und 0,000017 (μg/ml). In allen Behandlungen war Paraquat wirksamer als Deiquat. Der Anstieg in der Zellmembran‐Per‐meabilität war nichi mit äusseren Symptomen wie Chlorose oder Ausbleichen der Wedel verbunden. Für die Herbizidbedingte Veränderung der Zellmembran‐Permeabilität war Licht notwendig, doch konnte auch eine geringfügige Herbizidwirkung nach einer 48‐h‐Dunkelperiode bei Konzenlrationen > 0,17 μg/ml festgestellt werden.
Some studies on the sites of uptake of chlortoluron, isoproturon and metoxuron by wheat, Avena fatua and Alopecurus myosuroïdes
Authors: BLAIR A. M.
Published: July 2006

Summary: Résumé: Zusammenfassung

Chlortoluron, isoproturon and metoxuron applied to wheat (Triticum aesitvum (L.)), A vena fatua (L.) and Alopecurus myosuroïdes (Huds) at sowing caused less damage if the herbicides were restricted to the region above the seed by an activated charcoal layer. AH three herbicides, when applied to seedlings of the same species also had their main activity through the soil, an activated charcoal layer at seed level decreasing damage from post‐emergence sprays of isoproluron. Germination and/or establishment of A. myosuroïdes was better from seeds sown at or near the surface, hut the reverse was true for A. fatua, which showed weak germination and/or establishment from seed on the soil surface.

Rechterches sur les sites d'absorption du chhrtoluron, de l'isoproturon et du métoxuron par le blé. A vena fatua et Alopecurus myosuroïdes

Le chlortoluron, l'isoproturon et le métoxuron appliqués au semis sur du blé (Triticum avstivum (L.), Avena fatua (L.) et Alopecurus myosuroïdes (Huds.) ont causé moinsde dommages si les herbicides restaient localises dans la region située audessus des semences grâce à une couche de charbon activé. Les trois herbicides, lorsqu'ils furent appliqués aux plantules des mêmes cspèces, ont aussi exercé leur principale activitéà travers le sol; une couche de charbon active au nivcau des semences a dim inué les dommages provoques pour des traitements effectues avee de l'isoproturon en posttevée.

La germination atnsi que l'etablissement d'A. myosuroïdes ont été meilleurs à partir de sentences semées en surface, ou prés de la surface mais ce fut l'inverse pour A. fatua qui montra une germination et un etablissement plus faibles lorsque le semis a été fait en surface.

Untersuchungen zum Ort der Aufnahme von Chlortoluron. Isoproturon und
Metoxuron bei Weizen, A vena falua und A lopecurus myosuroides

Wenn Chlortoluron, Isoproturon und Metoxuron zu Weizen (Triticum aestivum (L.)), Arena fatua (L.) und Alopecurus myosuroïdes (Huds.) zum Zeitpunkt der Saat appliziert wurden, traten weniger Schäden auf. wenn die Herbizide durch eine Aktivkohlcschicht oberhalb der Samen verblieben. Auch wenn die Herbizide auf junge Pflänzchen appliziert wurden, wirkten sie hauptsachlich über den Boden Durch eine Aktivkohleschicht in der Samenzone wurde die Wirkung von Nachauflaufbehandlungen mil Isoproluron abgeschwächl. Bei A myosuroïdes war die Keimung und/oder das Wachstum besser, wenn sich die Samen auf oder nur knapp unterhalb der Bodenoberfläche befanden. Bei A. fatua was es urngekchrt, hier war die Keimung und/oder die Entwicklung nur schwach. wenn sich die Samen auf dem Boden befanden.
The use of glyphosate in fruit trees: effects on the suckers and on the trees
Authors: ATKINSON D.J , STOTT K. G. , O’KENNEDY N. D. , ABERNETHYS W. , ALLEN J. G.
Published: July 2006

Trails with glyphosate spred onto the soil around profusely suckering apple cherry pear and plum trees so as to wet the suckers, were carried out at ballygagn. Are East malling Kent; Long ash tom, Bristol and Loughall N Ireland Trees were sprayed to simulate normal weed killing in winter when the suckers were dormant, in April when the sucker buds had recently burst and in june when the sucker were in full leaf no damage was cused to the parent trees in the year of treatment or the following year in any of the trails. No glyphosate residues (< 1ppm) were found in the leavws of the parent apple tree at all soles sucker deths or damage was greater and apple trees. At all sites sucker death or damage was greatest and re grow the least with the full leaf spray. Damage was greater with the April than the January cpray Sucketrs of the different kinds of from varied in susceptibility ot glyphosate There was no damage ot the parent trees at long Ashton when suckers were sparyed to run off in July