bluuebunny/crossref_metadata_2025 huggingface dataset:
TRIAZINE HERBICIDES ON MAIZE AND THEIR RESIDUAL EFFECTS ON FOLLOWING CROPS*
Authors: SAGHIR A. R. , CHOUDHARY A. H.
Published: July 2006

Summary. Pre‐emergence application of 2–5 kg/ha (a.i.) of atrazine or simazine was the most effective treatment for control of broad‐leaved weeds in maize. Other triazines injured maize at all rates tested. Among the crops following maize treated with atrazine or simazine at 2–5 kg/ha, sugar beet was injured whereas wheat, oats, vetch, onions and soybeans were not.

Post‐emergence application of triazine herbicides was not effective and did not increase maize yields significantly over those of the unweeded plots. Wheat, oats, vetch and sugar beet were injured when following maize treated with post‐emergence sprays; onions and soybeans showed no visible injury except from atrazine or simazine at 5 kg/ha or more, and from mixtures of atrazine+prometryne or atrazine+ametryne at 12–5 kg/ha.

Les triazines herbicides sur le mais et leurs arrière‐effets sur les cultures suivantes
FACTORS AFFECTING THE PHYTOTOXICITY OF PARAQUAT*
Authors: BOVEY R. W. , DAVIS F. S.
Published: July 2006

Summary. Temperatures of 5–6° C delayed leaf necrosis of glasshouse‐grown oats (Avena sativa), winter peas (Pisum sativum), huisache (Acacia farnesiana), mesquite (Prosopis julijiora var. glandutosa), live oak (Quercus virginiana) and yaupon (Ilex vomitoria) for at least 48 hr after treatment with paraquat as compared with higher temperatures. After 96 hr, oats, winter peas, huisache and mesquite at 5° C usually showed as much necrosis as plants at 24–28° C. Similar results were obtained with live oak and yaupon, and with yaupon in the field, except that longer periods were sometimes required for plants at low temperatures to develop injury comparable with that at higher temperatures.

Washing yaupon and live oak leaves 1 hr after application reduced the effectiveness of paraquat regardless of temperature, but washing winter peas 10 min after application had little or no effect on phytotoxicity. Field‐grown mesquite showed extensive leaf necrosis when leaves were washed after 20 min, live oak leaves similarly treated and washed were not injured, while the response of winged elm (Ulmus alata) was intermediate.

Percentage leaf necrosis of mesquite, winged elm, yaupon and live oak increased with increasing paraquat concentration; 6–9 μg/leaf on mesquite and 20 μg/leaf on winged elm gave 100% necrosis after 4 days. Complete leaf necrosis of live oak and yaupon was not attained during this period even with 80 μg/Ieaf.

Nursery‐grown mesquite, yaupon and greenbriar (Smilax bona‐nox) and natural stands of yaupon were treated at two growth stages, in March and May. Paraquat was more effective on mesquite when applied in May, but there were no differences with the other species.

Facteurs affectant la toxicité du paraquat
THE INCIDENCE OF DORMANCY IN TWO‐NODE STEM AND RHIZOME FRAGMENTS OF POLYGONUM AMPHIBIUM L.
Authors: CHANCELLOR R. J.
Published: July 2006

Summary. Monthly samples of field‐grown rhizomes and aerial stems of Polygonum amphibium were tested for innate dormancy during parts of 2 years in England and during 5 months of a third year in southern Germany. All stems and rhizomes were cut into two‐node fragments, planted in soil in a warm glasshouse, and the new shoots counted after 3 weeks. Dormancy per month for different categories of stems varied from 0 to 23%, averaging 4–3% for all fragments tested but only 1–3% for mature buds. No evidence of a dormant period was found in either country.

Incidence de la darmance dans une tige à deux noeuds et des fragments de rhizome de Polygonum amphibium L.
UNTERSUCHUNGEN ZUR BIOLOGIE UND ÖKOLOGIE DER HÜHNER‐HIRSE ECHWOCHLOA CRUS‐GALLI L. BEAUV.
Authors: BROD G.
Published: July 2006

Summary. 1. Echinochloa crus‐galli is a typical grass weed of root crops in warmer regions, germinating late and thus covering the soil at a late stage. It originates in central and east Asia and is now a weed of world‐wide importance.

2. High temperatures are necessary for germination which begins in spring, but not before the soil temperature reaches 15° C. Minimum, optimum and maximum germination temperatures of 13° C, 20–30° C and 40° C were found in S.W. Germany.

3. Seeds of E. crus‐galli are dormant during the first 3–4 months after harvest. Those developing relatively early in the growing season require rather longer for after‐ripening than seeds which mature later.

4. For optimum germination, water saturation of the soil of 70–90% is required.

5. Soil acidity has some influence, and there is an apparent germination optimum around neutrality. Light also induces germination.

6. Seeds can emerge from a relatively wide range of depths. Greatest emergence and the strongest plants resulted from seeds at 2–6 cm, but even from 10 cm a high percentage of seedlings is likely to emerge.

7. Further development proceeds rapidly. The first panicles arc already formed 6–7 weeks after emergence in favourable conditions, but full maturity is possible only if there are high temperatures in late summer.

8. E. crus‐galli is a hygrophilous species, with best development on medium heavy soil, sandy loam or loamy sand with sufficient water supply.

9. E. crus‐galli is indifferent to the lime content of the soil.

10. Best development occurs with high fertility, and a rich supply of nitrogen is especially important.

Recherches sur la biologie et écologie du panic Echinochloa crus‐galli (L.) Beauv.
CHEMICAL CONTROL OF FERTILE SPARTINA TOWNSENDII (S.L.) ON THE CHESHIRE SHORE OF THE DEE ESTUARY
Authors: TAYLOR MONICA C. , BURROWS ELSIE M.
Published: July 2006

Summary. Chemical assay of paraquat in Spartina plants treated in the field in 1964 showed that it had been translocated into the underground system both in plants which continued shoot growth after treatment and in plants of which the aerial system had been destroyed. Translocation of a toxic substance from one leaf treated with paraquat to other shoots on the same Spartina plant was demonstrated in the laboratory. Paraquat at 2 lb/ac applied in the glasshouse to Spartina plants at four stages between germination and flowering became less effective with increase in age of the plants. This decline in susceptibility was not correlated with development of the rhizome system nor with onset of flowering. It is suggested that the use of paraquat for destruction of mature Spartina sward is inadvisable until more information is available, but that trials with paraquat on seedlings and very young plants invading open areas of foreshore may well prove profitable.

La lutte chimique contre les formes fertiles de Spartina townsendii (s.l.) sur la cite du Cheshire dans l'estuaire de la Dee

II. Réaction de Spartina au traitement avec le paraquat

Ré sumé.

Des essais effectués au champ en 1964, contre des plantes de Spartina ont montré que le paraquat migrait dans I'appareil souterrain, aussi bien dans les plantes qui continuaient à pousser aprè le traitement que dans celles dont la partie aérienne avait été détruite. La migration d'une substance toxique depuis une feuille traitée avec le paraquat vers d'autres tiges de la meme plante de Spartina a é té démontrée au laboratoire. Le paraquat a 2,2 kg/ha, appliqué en serre sur des plantes de Spartinaà quatre stades entre la germination et la floraison, devint moins efficace à mesure que les plantes vieillissaient. Cette diminution de la sensibilité ne fut pas liée au développement du système rhizomateux ni avec le début de la floraison. Les auteurs pensent que l'utilisation du paraquat pour la destruction de pelouses de Spartina arrivées a maturity n'est pas à recommander jusqu'à ce que l'on ait plus d'informations à ce sujet. Toutefois des traitements avec le paraquat sur des plantules et de tres jeunes plantes s'installant dans des aires ouvertes de plages peuvent se montrer avantageux.
WEEDS AS A FACTOR DEPRESSING FOREST GROWTH*
Authors: WILDE S. A. , SHAW B. H. , FEDKENHEUER A. W.
Published: July 2006

Summary. The consumption of water by weeds was determined on the basis of the loss in yield of timber suffered by 28–32–year‐old plantations of red pine (Pinus resinosa Ait.). Soil and biomass analyses included several pairs of closely located stands established simultaneously on either cultivated or weed‐supporting soils. The water supply of 1050 metric tons/ac, available during the growing season, was estimated as the algebraic sum of precipitation, winter storage, condensed vapour, evaporation of intercepted rainfall and gravitational discharge. The biomass of plantations on soils of satisfactory nutrient content and aeration consumed about 500 kg water for production of 1 kg dry matter. The diversion of available water by weed cover on soils of high potential site indices approached 100 kg per kg oven‐dry tissues. Blueberries, sweet fern and other heath plants, with initial weight of about 10 metric tons/ac, caused more than 50% loss in the expected volume of merchantable timber. The established relations facilitate an estimate of the productive potential of weed‐supporting soils and the choice of an appropriate tree spacing of forest plantations.

Les mauvaises herbes, facteur inhibant de la croissance des essences forestières

La consommation d'eau par les mauvaises herbes a étéévaluée en rapport avec la perte de rendement en bois éprouvée par des plantations de pins rouges (Pinus resinosa Ait.) âgés de 28 à 32 ans. Des analyses du sol et de l'ensemble de la végétation ont été effectuées simultanément par paires dans des stations voisines sur des aires maintenues propres par des facons culturales ou infestées de mauvaises herbes. L'apport d'eau, de 2625 tonnes a l'hectare durant la pdriode de croissance, fut considéré comme la somme alg6– brique des precipitations, du stockage hivernal, de la condensation de la vapeur, de l'éva‐poration de la pluie interceptée et de l'e'coulement par gravité. L'ensemble de la masse végétale des plantations, sur des sols d'un niveau de fertilité satisfaisant et convenablement aérés, consomme environ 500 kg d'eau pour la production de 1 kg de matiére séche. Le détournement d'eau disponible par la couverture des mauvaises herbes sur des sols à haut potentiel de fertilité approcha de 100 kg par kg de tissu dessé chéà l'étuve. Les myrtilles, les Myrica ('sweet fern’) et autres plantes de landes, avec un poids initial d'environ 25 tonnes a l'hectare provoquerent une perte de plus de 50% du volume attendu de bois commercialisable. Les relations établies facilitent l'estimation du potentiel de production des sols infestéd de mauvaises herbes et le choix d'un espacement approprié entre les arbres dans les plantations forestières.
INFLUENCE OF SOIL PROPERTIES ON PHYTOTOXICITY OF 4–AMlNO‐3,5,6–TRICHLOROPICOLINIC ACID (PICLORAM)
Authors: GROVER R.
Published: July 2006

Summary. Effective dosages of picloram (4–amino‐3,5,6–trichloropicolinic acid) required to reduce fresh weight of sunflowers (Helianthus annuus L. var. Menonite) were determined for seven Saskatchewan soils under controlled environmental conditions. The relationships between ED50 value and clay content, organic matter content and cation exchange capacity were evaluated by correlation and regression analysis for possible usefulness in predicting dose requirements. ED50 values were also determined for Weyburn loam and in culture solutions adjusted to various pH levels.

There Was no significant correlation between ED50 values of picloram and soil clay content or cation exchange capacity. ED50 values were highly correlated with soil organic matter content, and they increased as the soil pH was lowered or raised from pH 6.5. The increase in ED50 values in the acidic range was attributed to adsorption of the unionized molecules of picloram on the organic matter in the soil. The increase in ED50 values in the alkaline range may be mainly due to reduced uptake of the ionized acid by plant roots.
THE BASIS OF THE DIFFERENTIAL PHYTOTOXICITY OF 4‐HYDROXY‐3,5‐DI‐IODOBENZONITRILE*
Authors: DAVIES P. J. , DRENNAN D. S. H. , FRYER J. D. , HOLLY K.
Published: July 2006

Summary. Ioxynil added to culture solution was of comparable toxicity to mustard, pea and barley at the end of a 2‐week treatment period. When the destruction of chlorophyll and the decrease in reduction of 2,3,5‐triphenyl tetrazolium chloride were studied in leaf discs infiltrated with ioxynil solutions, three to five times the concentration of ioxynil was required for barley compared with mustard to produce a similar response. Pea was intermediate.

Recovery of ioxynil from sprayed barley plants (following washing) was highest I day after spraying; 2 days after, it had decreased to 37% and 9 days after, to 25% of the maximum. Recovery from mustard increased for the first 2–3 days and remained constant I'm the next 28 days. Separation of necrotic areas of treated mustard foliage confirmed that almost all the ioxynil remained in sprayed leaves which had subsequently been killed. Disappearance of ioxynil from barley was probably due to degradation, though only small amounts of ioxynil derivatives could be detected chromatographically.

It is concluded that the differential phytotoxicity between barley and mustard is largely based on retention, supported by small differences associated with plant morphology, rates of uptake of ioxynil, its effects on plant metabolism and the ability of barley to degrade or inactivate it. Almost all the differences between mustard and pea were dependent on large differences in retention and small differences in rate of uptake and interference by ioxynil with plant metabolism. The first two were removed by adding a surfactant, and the last was sufficient only to delay the onset of phytotoxicity.
AGROPYRON REPENS (L.) BEAUV.—SOME EFFECTS OF RHIZOME FRAGMENTATION, RHIZOME BURIAL AND DEFOLIATION
Authors: TURNER D. J.
Published: July 2006

Summary. A factorial experiment with couch grass (Agropyron repens (L.) Beauv.) grown in boxes examined the effects of rhizome fragmentation, planting depth and shoot removal on the survival of rhizome pieces, new rhizome growth and rhizome carbohydrate reserves.

Burial to 4 in. depth in sandy loam soil led to the death of 54% of 1 in. long rhizome pieces and 28% of 3 in. pieces. With all the segment lengths tested deeper planting decreased the proportion of buds which produced shoots.

Shoot removal every 14 days decreased the dry weight and carbohydrate content of the planted rhizomes and prevented new rhizome growth. Segments 1 or 3 in. long lost their carbohydrate reserves more quickly than 9 in. pieces. Rhizomes planted at 4 in. depth contained less carbohydrate after establishment than shallow‐planted material, and produced less new rhizome growth.

IS Agropyron repens (L.) Beauv.–Quelques effets de la fragmentation et de l'enfouissement du rhizome et de la defoliation
ADSORPTION AND DESORPTION OF SIMAZINE BY SOME ROTHAMSTED SOILS
Authors: WILLIAMS J. D. H.
Published: July 2006

Summary. The adsorption of simazine from, and subsequent desorption into, 0–01 M calcium chloride solution was investigated using twenty‐three Rothamsted soil samples from sites differing greatly in cropping history and manurial treatment. Organic carbon content was the only factor related to the ability of the soils to sorb simazine; this accounted for 90% or more of the variation between soils Equilibrium was attained during adsorption in from fewer than 2 to more than 24 hr. Equilibrium during desorption was only occasionally attained within 24 hr. Differences between theoretically predicted and measured concentrations of simazine in solution following desorption were least for soils that attained equilibrium fastest during adsorption. Differences in adsorption and desorption kinetics between soils could not be related to soil pH, organic carbon content or cropping and manuring history. Comparisons of unlimed and limed soils suggested that no simnazine was lost by acid hydrolysis during the experiments.

Adsorption et désorption de la simazine par quelques sols de Rothamsted
THE EFFECTS OF BENSULIDE ON THE GROWTH, MORPHOLOGY AND ANATOMY OF OAT ROOTS
Authors: CUTTER ELIZABETH G. , ASHTON F. M. , HUFFSTUTTER DONNA
Published: July 2006

Summary. Oat seedlings were grown by two different methods in various concentrations of bensulide. Root growth was inhibited, the roots were sometimes curved and root hairs were often present close to the root tip. Structural features of the treated roots included epidermal cells which were greatly elongated radially; short, pitied trachcary elements differentiated close to the root tip; and occasional lesions. One of the primary effects of bensulide appears to be inhibition of root growth, though it does not completely inhibit mitosis.
THE INFLUENCE OF HERBICIDES UPON THE ANTAGONISM BETWEEN BACILLUS SP, AND PSEUDOMONAS PHASEOLI
Authors: BALICKA N. , KREEL Z.
Published: July 2006

Summary. Prometryne, linuron and chlorpropham at concentrations between 10 and 100 ppm had only temporary effects on the growth of three strains of bacillus sp. type mesentericus in liquid culture; growth of Pseudamonas phaseoli was not affected. The sensitivity of Ps. phaseoli lo pure antibiotics was only slightly affected by the herbicides, hence the effects of the herbicides on the antagonism between the two organisms which were observed appeared to be attributable to disturbance of the metabolism oi Bacillus sp., and varied with the strain employed.
EFFECTS OF PARAQUAT ON THE ULTRASTRUCTURE OF MESQUITE MESOPHYLL CELLS*
Authors: BAUR J. R. , BOVEY R. W. , BAUR P. S. , EL‐SEIFYDR ZENAB
Published: July 2006

Summary. The effect of paraquat (l,1′‐dimethyl‐4,4′‐bipyridylium‐24) on the ultra‐structure of mesophyll cells of honey mesquite (Prosopis juliftora (Swartz) DC. var. glandulosa (Torr.) Cockerell) was studied by means of electron microscopic techniques. The first visible change induced by the herbicide was a rapid disintegration of the plasmalemma, followed by rupturing of the chloroplast membranes and loss of chloroplast turgor. Changes that occurred in plants treated and sampled in the dark were similar to those in plants treated and sampled in the light.

The only change of a biochemical nature detected was a marked reduction in the quantity of starch deposits in chloroplasts. No changes were noted in the mitochondria, Golgi bodies, endoplasmic reticulum or nucleus, or in the composition of the cytoplasm or cell walls of treated tissues.

Effets du paraquat sur I'ultrastructure des cellules du mésophylle de Prosopis

Resume

L'action du paraquat (1,1′‐diméthyle‐4,4′‐bipyridylium‐2A) sur l'ultrastructure des cellules de mésophylle de Prosopis (P. juliflora (Swartz) DC. var. glandulosa (Torr.) Cockerell) a été eatudiée au moyen des techniques de microscopie électronique. Le premier effet visible provoqué par l'herbicide fut une deasintegration rapide de la membrane cytoplasmique suivie de la rupture des membranes des chloroplastes et de la perte de la turgescence des chloroplastes. Les transformations qui apparurent dans les plantes traitées et conservées a l'obscurité, furent analogues á ceux des plantes traitées et exposées a la lumière.

Le seul changement de nature biochimique deacelé fut une reduction marquée de la quantité des dépôts d'amidon dans les chloroplastes. Aucun changement ne fut observe dans les mitochondries, l'appareil de Golgi, le réticulum endoplasmique ou le noyau, pas plus que dans la composition du cytoplasme ou des parois cellulaires des tissus traités.

Der Einfluss von Paraquat auf die Feinstruktur von Mesophyllzellen des Honig‐Mesquitebaums
CHEMICAL FALLOW CONTROL OF NUTSEDGE
Authors: RAY BIBHAS , WILCOX MERRILL
Published: July 2006

Summary. Field experiments were conducted to find a herbicide for complete control of nutsedge (Cyperus rotundus L.). We applied seventeen herbicides and some of their combinations as chemical fallow. EPTC and CP‐31675 (6‐tert‐butyl‐2‐chloro‐o‐acetotoluidide) gave good but only temporary control of nutsedge. Dichlobenil at 2·5 or 5 lb/ac gave fair control for 1 year. Rates of 10 or 20 lb/ac of dichlobenil controlled nutsedge completely for 1 year but severely reduced the yield of oats planted 5 months after application. The highest rate completely killed tubers and prevented reinfestation for 1 year. Analyses indicated no residue of dichlobenil or of its metabolite, 2,6‐dichlorobenzoic acid, in vegetative parts and seeds of oats planted 5 months after application of 2.5, 5 or 10 lb/ac of dichlobenil. At equivalent rates the herbicide TH‐073‐H (N‐hydroxymethyl‐2,6‐dichlorothiolbenzamide) gave control of nutsedge similar to that with dichlobenil. The combinations of 8 lb/ac amitrole‐T and 10 lb/ac dichlobenil or TH‐073‐H were just as effective in controlling nutsedge shoots and tubers as dichlobenil or TH‐073‐H applied alone. The mixture of dichlobenil plus CP‐31675, each at 5 lb/ac, gave excellent control of nutsedge and tubers for 1 year. The herbicides terbacil (3‐ter‐Nbutyl‐5‐chloro‐6‐methyluracil) or Du Pont 733 (3‐tert‐butyl‐5‐bromo‐6‐methyluracil) at 10 lb/ac provided almost complete control of nutsedge. Application of terbacil to plants aged 4–6 weeks gave better results than application to mature nutsedge in the fall.

La lutte chimique contre le cypirus
THE ADSORPTION OF LINURON, ATRAZINE AND EPTC BY MODEL ALIPHATIC ADSORBENTS AND SOIL ORGANIC PREPARATIONS
Authors: HANCE R. J.
Published: July 2006

Summary. Model adsorbents were prepared by treating cellulose phosphate powder with a series of alkyltrimethylammonium compounds in which the size of the alkyl group was varied from C8to C18. The adsorption of linuron, atrazine and EPTC by these materials was found to increase logarithmically with increasing chain length. The extent of the adsorption was large compared with the adsorption of these herbicides by a humic acid and by a preparation made by removing the bulk of the inorganic constituents of a peat soil with a mixture of HCl and HF. Since soil organic matter is thought to contain alkyl groups, it is concluded that the possible influence of such groups should be considered in any discussion of the mechanisms involved in the adsorption of organic molecules by soils.

Adsorption du linuron, de I'atrazine de l'EPTC par des adsorbants de la série aliphatique et des préparations organiques de sol
DIFFERENTIAL PHYTOTOXICITY OF ATRAZINE AND AMETRYNE TO BANANAS*
Authors: BARBA R. C. , ROMANOWSKI R. R.
Published: July 2006

Summary. In field screening trials for bananas (Musa acuminata var. Dwarf Cavendish) in Hawaii, ametryne (2‐methylthio‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) was less phytotoxic to bananas than atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine). Sand culture experiments showed that both herbicides were equally injurious to banana plants. Differential degradation of the herbicides by the plants did not account for the phytotoxicity observed. Both herbicides were partly metabolized by the plant to their common hydroxyl derivative (hydroxyatrazine) and two other unidentified metabolites after 3 and 7 days of exposure to nutrient solution containing 14C‐labelled ametryne and atrazine.

Phytotoxicity was directly related to leachability of the herbicides and negatively related to adsorption capacity of each soil for the herbicides. Organic matter content seemed to be correlated to the response observed. It was postulated that phytotoxicity in the field may have been attributed to differential location of the herbicide in relation to the roots.
A RAPID BIOASSAY FOR SIMULTANEOUS IDENTIFICATION AND QUANTITATJON OF PICLORAM IN AQUEOUS SOLUTION
Authors: REID C. P. P. , HURTT W.
Published: July 2006

Summary. When seeds of lettuce (Lactuca sativa L.) were placed on small squares of filter paper moistened with solutions of picloram (4‐amino‐3,5,6‐trichloropicolinic acid), the degree of inhibition on of root and hypocotyl elongation 72 hr later was related to picloram concentration. Inhibition was a useful parameter in determining quantities of picloram ranging from 0·03 to 7·2 μg. (Growth stimulation occurred from 0·00072 to 0·0072 μg. After paper chromatography of plant exudates containing 14C‐labelled picloram, location and quantities of picloram on the chromatograms were determined by the lettuce bioassay and compared with determinations by the methods of ultraviolet light sensitivity, 14C 4π strip scanning and 14C dilution calculations. Rf values determined lay all methods were identical, and the quantitative determination by the bioassay agreed closely with the calculations based on the amount of 14C detected by liquid scintillation counting.

Un essai biologique rapide d'idntification et de dosage de piclorame en solution aqueuse
UPTAKE, TRANSLOCATION AND METABOLISM OF SIMAZINE IN NORWAY SPRUCE (PICEA ABIES)
Authors: LUND‐HÖIE K.
Published: July 2006

Summary. Uptake, distribution and fate simazine (2‐chioro‐4,6‐biserthylamino‐s‐triazine) in 4‐year‐old seedlings of Norway spruce (Picea abies) are discussed. Simazine was found to be readily absorbed and distributed in the spruce seedlings. A positive relationship between the amount of simazine absorbed and the growth intensities of the plants indicates an active mechanism of uptake. A fixation of simazine in roots and sterm was observed.

Simazine was degraded by roots and stem to hydroxysimazine and two other unknown metabolites. No simazine and only metabolites could be traced in the needles, indicating a very rapid rate of metabolism in the root system. The glucose derivative of benzoxazinone was extracted from all parts of the spruce seedlings and is probably responsible for the hydrolysis of simazine.

The results indicate a very slow degradation of the metabolites to CO2 as one of the final products.
TRANSLOCATION OF AMINOTRIAZOLE AND DALAPON IN AG ROPY RON REPENS (L.) BEAUV.
Authors: LUND‐HÖIE K. , BYLTERUD A.
Published: July 2006

Summary. Tracer studies using single drops of solutions containing 3–amino‐1,2,4–triazole‐5–14C (aminotriazole‐14C) or 2,2–dichloropropionic acid‐2–14C (datapon‐14C) revealed that in couch plants (Agropyron repens (L.) Beauv.) growing under field conditions in the autumn and at the stage where the aerial shoots were 40–50 cm long, both compounds moved in both symplast and apoplast. Dalapon was less mobile in the symplast than aminotriazole and only negligible amounts of dalapon were translocated to the rhizomes. The nodes of the treated shoots appeared to act as barriers to translocation, a phenomenon more pronounced for dalapon than for aminotriazole.

Application to a basal green leaf led to a more uniform distribution of the compounds within plants and rhizomes than when the application was made to the youngest fully‐expanded leaf.

In couch plants with aerial shoots 10–15 cm long treated in the stubble, the distribution of both aminotriazole and dalapon was mainly restricted to the treated shoots. Even 15 days after application only trace amounts of radioactivity could be found in the rhizomes and untreated shoots.
THE PRESENCE OF 3, 4‐DICHLOROANILINE IN RICE GRAIN HYDROLYSATES
Authors: STILL GERALD G. , MANSAGER E. R.
Published: July 2006

Summary. Identification of 3, 4‐dichloroaniline in a hydrolysate of rice grain obtained from experimental plots treated with N‐(3, 4‐dichlorophenyl) propionamide (propanil) and in rice grain purchased on the consumer's market is reported. Rice grain harvested before the introduction of pesticides that contain 3, 4‐dichloroaniline but treated with isopropyl N‐(3‐chlorophenyl)carbamate (chlorpropham) yielded rice cereal from which, after caustic hydrolysis of the rice grain, 3‐chloroaniline was isolated. The presence of chloroaniline or chloroaniline‐containing compounds raises the question as to the source of the contaminants.
EFFECTS OF TIME OF SOWING OF SPRING WHEAT AN D DEFOLIATION OF AGROPYRON REFENS (L.) BEAUV. ON COMPETITION BETWEEN THEM
Authors: WILLIAMS E. D.
Published: July 2006

Summary. Spring wheat, sown at three different times, and Agropyron repens, defoliated at the same three times, were grown separately or together in pots kept in an open‐sided cage. The pots were widely spaced and adequately watered. Early sowing of wheat gave a greater grain yield than late sowing, and lessened the loss from competition with Agropyron. Early defoliation of Agropyron slowed its subsequent early growth more than did late defoliation, and plants defoliated early suffered more from competition with wheat. Competition, probably mainly for nitrogen, decreased tillering and the number of ears produced by wheat, more when sowing was late than early, but grain dry weight per ear was decreased equally at the three times of sowing. The rate at which wheat produced leaves was affected by competition only at the last date of sowing. In competition with wheat, Agropyron produced fewer shoots and ears, had lighter shoots and rhizomes, and ear emergence was slightly delayed.
THE PERSISTENCE OF SIMAZINE APPLIED ANNUALLY IN THE PROLONGED ABSENCE OF SOIL CULTIVATION
Authors: ALLOTT D. J.
Published: July 2006

Summary. Successive bioassays during 1966 and 1967 showed that simazine degradation reached 80% in 11 and 22i weeks, respectively, in soil from the 0–2 in. horizon of a gooseberry experiment to which simazine had been applied annually in the absence of soil cultivation from 1960. Where an annual farmyard‐manure mulch was also applied, the same loss of residual activity was reached in 10 and 20 weeks. This mulch initially reduced the simazine level rapidly compared to that of unmulched soil, but the subsequent rates of degradation were similar. The rate of simazine degradation depended more on environmental conditions each year than on soil type. The results indicate that an annual simazine degradation in excess of 80% can be expected in Loughgall soils in conditions of non‐tillage. Even if simazine applications continued indefinitely at an annual dose of 20 Ib/ac–the current dose in the gooseberry experiment–a large residue accumulation could not occur with or without a mulch.

Persistance de la simazine appliquée annuellement en l'absence prolongée de façons culturales
CROISSANCE, RHIZOGENESE, TENEUR EN ANTHO‐CYANES ET CATABOLISME AUXINIQUE (IN VITRO ET IN VIVO) CHEZ ZEA MAYS TRAITÉ PAR L'HYDRAZIDE MALÉIQUE
Authors: GASPAR THOMAS , GLEDJO OLIVIER
Published: July 2006

Résumé. Des plantules de mais sont cultivées à partir de la graine, à 1'obscurite ct i la lumiere, sur des solutions tamponnées (pH5,8) d'hydrazidemalfrque (HM) de concentrations allant de 10′ a 10−3 M. AUX faibles concentrations (10° et 10−6 M), I'HM stimule la croissance et la formation des racines; aux autres concentrations, it est inhibiteur. L'inhibition de croissance provoquee par I'HM est accompagnee d'une augmentation de poids sec et de la teneur en anthocyanes.

L'HM n'influence pas in vitro la destruction de I'auxine par des extraits de mais, mais les extraits de plantes traitees par cette substance degradent l'hormone moins rapidement; parallelement, l'activite catalasique est diminuee mais l'activite péroxydasique est augmented. Le mode d'action de I'HM sur la croissanee et la rhizogenpse, compart à celui de la lumierc, est discute en rapport avec ses effets sur le raetabolisme auxinique.
FACTORS INFLUENCING THE HERBICIDAL EFFICIENCY OF MCPA AND MCPB IN THREE SPECIES OF MICRO‐ALGAE
Authors: KIRKWOOD R. C. , FLETCHER W. W.
Published: July 2006

Summary. The herbicidal activity of MCPA and MCPB was compared using three species of unicellular algae grown in liquid mineral salt medium. MCPB inhibited growth, respiration and phosphate uptake to a greater degree than MCPA and appears to be inherently toxic at concentrations of at least 2·5 × 10−4 M. The enhanced activity of MCPB coincided with more efficient absorption. Uptake of both compounds appears to be optimal at pH conditions favouring movement as the undissociated molecule.

Facteurs infiuencant l'efficacite herbicide du MCPA et du MCPB sur trois espèces d'algues micro‐scopiques

Résumé. L'activité herbicide du MCPA et du MCPB a été comparée en utilisant trois espéces d'algues unicellulaircs cultivées en milieu liquide renfermant des sets minéraux. Le MCPB inhibe la croissance, la respiration et l'absorption du phosphate à un degré plus éevé que le MCPA et il semble être essentiellement toxique à des concentrations d'au moins 2,5 × 10−4 M. L'activité plus grande du MCPB coïncide avec une absorption plus complète. L'absorption des deux composés semble étre optimale aux conditions dec pH favorisant leur migration sans dissociation de la molécule.

Faktoren, welche die hrbizide Wirkung von MCPA und MCPB gegen drei Mikro‐Algen‐Arlen beeinfiussen

Zusammenfassung. Die herbizide Wirksamkeit von MCPA und MCPB wurde bei drci Arten einzelliger Algen, die in flüssigem Mineralsalzmedium angezogen wurden, vcrglichen. MCPB hemmt Wachstum, Respiration und Phosphataufnahme starker als MCPA und ist offcnsichdich in Konzentrationen von mindestens 2,5 × 10−4 M absolute toxisch. Die bessere Wirkung von MCPB geht mit einer besseren Absorption parallel. Die Aufnahme beider Substanzen ist offensichtlich unter solchen pH‐Bedingungen optimal, die den Transport in Form von undissozierten Molekülen begünstigen.
UNTERSUCHUNGEN UBER DEN EINFLUSS LANGJAHRIG WIEDERHOLTER ANWENDUNG VON DNOC UND 2,4‐D AUF IHREN ABBAU IM BODEN
Authors: UND K. HURLE , RADEMACHER B.
Published: July 2006

Zusammenfassung. Es wird über die Abbaugeschwindigkeit von DNOC und 2,4‐p in eistmals und in langjahrig wiederholt behandeltem Boden berichtet. Der langjahng wiederhoh behandelte Boden stammte aus einem Feldversuch, in dem diese Herbizide in 12 Jahren 12 mal zur Unkrautbekämpfung in Getreide angewandt wurden. Wenn Boden der DNOC‐Parzellen 7 Monate nach seiner letzten Behandlung erneut mit DNOC versetzt wurde, war gegenüber erstmals behandeltem kein Unterschied in der Abbaugeschwindigkeit festzustellen. Wurde Boden der 2,4‐D‐Parzcllen 8 Monate nach der letzten Applikation wieder mit 2,4‐D versetzt, verlicf der Abbau des Herbizids schneller als im Boden der zum erstenmal mit dem Herbizid behandelt worden war.

Effet d'un traitement à long terme avec le DNOC et le 2,4‐D sur leur dègradation dans le sol

Résumé. La degradation du DNOC et du 2,4‐D a étéétudiée dans un sol traité pour la premiére fois et dans un sol provenant de parcelles en plein champ qui ont recu des traitements annuels durant une période de dotize ans pour le désherbage des céréales. Quand le sol provenant des parcelles traitées au DNOC fut examiné sept mois aprés la derniére application, il ne fut pas constaté de difference dans le taux de degradation par rapport ausol traits pour la premiére fois. La dégradation du 2,4‐D dans lesol provenant des parcelles traitées et examine huit mois aprés la derniere application fut plus rapide que dans le sol des parcelles traitées pour la premiére fois.

The effect of long‐Urm treatment with DNOC and 2,4‐D on their breakdown in soil

Summary. The breakdown of DNOC and 2,4‐D was studied in soil treated for the first time and in soil from field plots which had received annual treatments over a period of 12 years for weed control in cereals. When soil from DNOC‐treated plots was tested 7 months after the last application, there was no difference in the rate of breakdown from that in soil treated for the first time. The breakdown of 2,4‐D was more rapid in soil from the treated plots, tested 8 months after the last application, than in soil from plots treated for the first time.
SELECTIVITY OF PYRAZON AND BENZTHIAZURON IN SUGAR BEET
Authors: ESHEL Y. , SOMPOLINSKY D.
Published: July 2006

Summary. Pyrazon (5‐amino‐4‐chloro‐2‐phenylpyridazin‐3(2H)‐one) and benzthiazuron (N‐(2‐benzothiazolyl)‐N′‐methylurea) were compared in respect to their effects on photosynthesis and growth of sugar beet, and to their movement in soil. Benzthiazuron had a five‐fold greater inhibitory effect than pyrazon on photosynthesis, and a ten‐fold greater inhibitory effect on the growth of sugar beet grown in treated culture solution. On the other hand, sugar beet was more tolerant to benzthiazuron than to pyrazon when grown in soil treated pre‐emergence with the herbicides.

Leaching of pyrazon in clay soil appeared to be greater than that of benzthiazuron. Both herbicides entered the emerging seedlings through their roots, and hence movement of the compounds to the root zone by excess irrigation might be injurious to sugar beet. This was found to be more likely to occur with pyrazon than with benzthiazuron.

Sélectivité du PCA et du benzthiazuron pour la betterave sucrière

Résumé. Le PCA (5‐amino‐4‐chloro‐2‐phénylpyridazine‐3(2H)‐one) et le benz‐thiazuron (N‐(2‐benzothiazolyl)‐N′‐méthylurée) ont été compareés en ce qui concerne leurs effets sur la Photosynthèse et la croissance de la betterave sucrière et leur migration dans le sol. Le benzthiazuron manifesta un effet inhibiteur cinq fois plus grand sur la croissance de la betterave sucrière cultivée en solution traitée. En revanche, la betterave sucrière fut plus résistante au benzthiazuron qu'au PCA quand elle fut cultivée dans un sol traité en pré‐levée avec ces herbicides.

Le lessivage du PCA dans un sol argileux apparut plus important que celui du benzthiazuron. II a été constaté que les deux herbicides pénétraient dans les plantules, après la Ievée, par les racines et que la migration des produits dans la zone des racines sous I'effet d'une irrigation excessive pouvait provoquer des dégâts sur la betterave à sucre. II fut constaté que ce phénomène était plus probable avec le PCA qu'avec le benthiazuron.

Selektivität von Pyrazon und Benzthiazuron in Zuckerrüben

Zusammenfassung. Pyrazon (5‐Amino‐4‐chlor‐2‐Phenylpyridazin‐3(2H)‐one) und Benzthiazuron (N‐(2‐Benzothiazolyl)‐N′‐methyl‐harnstoff) wurden in ihrer Wirkung auf die Photosynthese und das Wachstum von Zuckerrüben sowie auf ihre Beweglichkeit im Boden verglichen. Das Herbizid Benzthiazuron hatte einen fünffach grösseren Hemmeffekt auf das Wachstum von Zuckerrüben, die in einer behandelten Nährlösung wuchsen. Andererseits waren Zuckerrüben toleranter gegenüber Benzthiazuron als gegenüber Pyrazon, wenn sie in Boden wuchsen, der im Vorauflauf mit diesen Herbiziden behandelt worden war.

Die Einwaschung von Pyrazon in Tonboden war offensichtlich grösser als diejenige von Benzthiazuron. Es konnte festgestellt werden, dass beide Herbizide in die auflaufenden Keimpflanzen durch deren Wurzel eindrangen. Daher könnte die Verlagerung der Herbizide in die Wurzelzone durch Überschussbewässerung die Zuckerrüben schädigen. Dies ist bei Pyrazon offensichtlich eher zu erwarten als bei Benzthiazuron.
ÜBER ABBAUGESCHWINDIGKEIT UND VERTEILUNG VON PHENMEDIPHAM IM BODEN
Authors: KOSSMANN K.
Published: July 2006

Zusammenfassung. Phenmedipham, wirksamer Bestandteil des im Rübenbau ver‐wendeten Nachauflaufherbizides Betanal®, wird in Rübenböden mit geringem Humusanteil und schwach saurer Reaktion sowohl im Freiland als auch im Gewächshausversuch kontinuierlich abgebaut.

Je nach Versuchsbedingungen und Bodenqualität wurden Halbwertzeiten zwischen 28 und 55 Tagen registriert. Der formulierte Wirkstoffdringt bei Freilandapplikation in nur geringem Ausmass in Bodenschichten ein, die tiefer als 5 cm unter der Oberfläche liegen.

Rate of decomposition and distribution of phenmedipliam in soil

Summary. Phenmedipham, the active ingredient of the post‐emergence sugar beet herbicide Betanal®, is continuously decomposed in the slightly acid soils of low humus content used for beet production. The decomposition was studied both in the field and in the glasshouse.

Half‐lives of 28–55 days were recorded, depending on the experimental conditions and soil type. In field experiments the formulated herbicide was found to penetrate only very little beyond a depth of 5 cm.

Taux de décomposition et distribution du phenmédiphame dans le sol

Résumé. Le phenmédiphame, matière active de l'herbicide de post‐levée pour betteraves sucrifères, dénommé Bétanal®, est décomposé de façon ininterrompue dans les sols légère‐ment acides, à faible teneur en humus, où la betterave est cultivée. La décomposition du phenmédiphame a étéétudiée, à la fois en serre et au champ.

Des demi‐vies de 28 et 55 jours furent enregistrées en fonction des conditions expéri‐mentales et du type de sol. Dans les expériences au champ, il fut constaté que l'herbicide ne pénètre que très peu au‐delà d'une profondeur de 5 cm.
SEED POLYMORPHISM AND GERMINATION II. THE ROLE OF HYBRIDIZATION IN THE GERMINATION POLYMORPHISM OF RUMEX CRISPUS AND R. OBTUSIFOLIUS
Authors: WILLIAMS J. T.
Published: July 2006

Summary. The morphology of Rumex crispus L., R. obtusifolius L. and putative hybrids was examined. There appeared to be evidence of introgressive hybridization, particularly with backcrossing to R. crispus. Seed germination in plants from a mixed population varied widely, but when plotted against the hybrid index for the parent plants the could be partially separated in respect of germination behaviour. Some of the polymorphism previously described may have resulted from inclusion in the tests, together with pure parental types, of plants of hybrid origin which had introgressed to such an extent that they were almost indistinguishable from the parent species. The implications of the discussed.
THE EFFECTS OF PICLORAM AND 2,4‐D ON PLANT CELL MEMBRANES
Authors: Bachelard E. P. , Ayling R. D.
Published: July 2006

Summary. The herbicide Tordon 50D (picloram + 2,4–D) caused severe shrinkage of the protoplasts of all cells of Pinus radiata needle segments within 24 h of treatment. Measurements of the resistance of these tissues to low‐frequency and to high‐frequency electrical currents showed a loss in the integrity of the plasmalemma within 4–8 h of treatment. Tordon 22K (picloram) had no such effects. The results with Tordon 50D could be attributed solely to the 2,4‐D content.

Both Tordon 50D and Tordon 22K disrupted chloroplast structure in leaf discs, and the integrity of cell membranes in stem tips, of Eucalyptus viminalis.
THE RESPONSE OF TOBACCO TO SEEDBED APPLICATION OF DIPHENAMID
Authors: Duffy S. L. , Audia W. V.
Published: July 2006

Summary. Seeds of three tobacco Nicotiana tabacum L.) varieties were soaked in water for 0, 1, 3 or 5 days and treated, after sowing in glasshouse flats, with NN‐dimethyl‐αα‐diphenylacetamide (diphenamid) at 4·5 kg/ha 1, 3 or 5 days after sowing or at the cotyledonary stage. Unsprayed series were included as controls. Diphenamid caused thinning of seedlings in all varieties, but one (Maryland Catterton) showed some tolerance. All varieties showed stunting and malformations from diphenamid, particularly when seeds soaked for 5 days were treated either 1 or 5 days after sowing.
CONTROL OF MIKANIA CORDATA (BURM. f.) B. L. ROBINSON IN PLANTATION CROPS USING PARAQUAT
Authors: SETH A. K.
Published: July 2006

Summary. A single application of paraquat at 0·56 kg/ha applied in 224 l/ha gave short‐lived control of Mikania cordata. An increase in duration of control was obtained either by increasing the dose from 0·28 kg/ha to 1·12 kg/ha with a constant volume rate (224 l/ha) or by using a constant dose (0·56 kg/ha) and reducing the volume from 896 l/ha to 112 l/ha. Complete eradication of M. cordata was achieved by applying paraquat at 0·56 kg/ha or 0·28 kg/ha followed 2‐3 weeks later by a second application at 0·28 kg/ha in 112 l/ha.

La lutte contre Mikania cordata (Burm. F.) B. L. Robinson dans les cultures au moyen du paraquat
EFFECTS OF N‐(1,1‐DIMETHYLPROPYNYL)‐3,5‐ DICHLOROBENZAMIDE ON THE ANATOMY OF AGROPYRON REPENS (L.) BEAUV.
Authors: PETERSON R. L. , SMITH L. W.
Published: July 2006

Summary. .

Plants of Agropyron repens (L.) Beauv. which bad been sprayed with N‐(1,1‐dimethylpropynyl)‐3,5‐dichlorobenzamide (pronamide) were examined for changes in external and internal morphology at various times after spraying. Cell enlargement, some necrosis, and an increase in nuclear volume characterized treated rhizome apices. Abnormal metaxylem vessel elements and necrotic phloem were characteristic of the rhizome vascular tissues. Roots showed precocious differentiation and maturation of tissues and eventual vacuolation of the apical maeristem, resulting in complete inhibition of root growth. Nuclei of root meristem cells were much enlarged and contained several nucleoli.

Effets du N‐(1,1‐diméthylpropynyl)‐3,5‐dichlorobenzamide sur l'anatomie de l' Agroyron repens (L.) Beauv.
COMPLEX FORMATION AS AN ADSORPTION MECHANISM FOR LINURON AND ATRAZINE
Authors: HANCE R. J.
Published: July 2006

Summary. Measurements were made of the effect of exchangeable cations on the adsorption of linuron and atrazine by an ion‐exchange resin, cellulose phosphate powder, bentonite and a peat soil. The cations studied were Ca2+, Ni2+, Cu2+, Fe3+ and Ce4+. The results with linuron were consistent with the hypothesis that complex formation with exchangeable cations is a possible mechanism of adsorption. This was not so with atrazine due to complications arising from pH effects, and it seems unlikely that adsorption of atrazine by this process is significant.
AUTOMATED COLORIMETRIC PROCEDURE FOR THE DETERMINATION OF TOTAL AND UNCHANGED UREA HERBICIDE RESIDUES IN SOIL
Authors: And J. A. GUTH , VOSS G.
Published: July 2006

Summary. An automated colorimetric method has been described for the determination of both total and unchanged herbicide residues of the urea herbicides fluometuron, metobromuron, chlorbromuron and chlortoluron. The method is based on the well‐known Bratton‐Marshall diazotization‐coupling reaction for aromatic amines and is also applicable for other phenylureas as well as for N‐phenylcarbamate and anilide herbicides. The procedure is especially useful when large series of soil samples have to be analysed, for instance in connection with leaching experiments. Manual work and working time have been reduced with this method by up to 50%.
DEGRADATION OF FLUORODIFEN‐1′‐14C BY PEANUT SEEDLING ROOTS
Authors: EASTIN E. F.
Published: July 2006

Summary. Degradation of p‐nitrophenyl‐α,α,α:‐trifluoro‐2‐nitro‐p‐tolyl ether (fluorodifen) labelled with 14C in the 1 position of the p‐nitrophenyl ring (1′‐14C) proceeded rapidly in peanut (Arachis hypogaea L. cv. Starr) seedling roots. All degradation products were present after only 2 h.

The major degradation products for fluorodifen‐1′‐14C were the water‐soluble compounds p‐nitrophenol and Unknown I, a polar compound or complex which remained on the origin during thin‐layer chromatography. Minor products included p‐nitrophenyl‐α,α,α‐trifluoro‐2‐amino‐p‐tolyl ether, p‐aminophenyl‐α,α,α‐trifluoro‐2‐nitro‐p‐tolyl ether and traces of p‐aminophenol. No p‐aminophenyl‐α,α,α‐trinuoro‐2‐amino‐p‐tolyl ether was detected. The p‐aminophenol previously reported [PL Physiol., Lancaster, 44,1397‐1401 (1969)] was not p‐aminophenol, but primarily Unknown I with a possible trace of p‐aminophenol.

Fluorodifen continued to be absorbed throughout the 72‐h treatment period.
THE EFFECT OF INTRA‐SPECIFIC COMPETITION ON THE DEVELOPMENT OF CHENOPODIUM ALBUM L.
Authors: ERVIÖ LEILA‐RIITTA
Published: July 2006

Summary. Plants of Chenopodium album L. were grown at a range of different densities in each of three years. The stem diameter, the number of main branches and the size and number of leaves decreased with increasing density as did weight and leaf area per plant. The dry‐matter yield per unit area increased with density up to 576 plants/m2 in two of the three trial years. The proportion of the seed yield relative to the total yield was higher in the leas dense than in the dense stands, or was almost constant. Density did not affect the seed yield per unit area, but seed yield per plant fell as density increased. Maximum seed production was 41 900 per plant and the mean seed yield over the three years was 8300 seeds per plant. The percentages of nitrogen, phosphorus, potassium and calcium were highest when the plants were at an early stage of development. The proportions of these elements in the dry‐matter yield decreased with increasing age of the plants. The density of the stand did not affect the percentages of elements but the total amounts per plot were greatest at the flowering stage and in the denser stands.