bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE GENETIC RESPONSE OF BARLEY TO DDT AND BARBAN AND ITS SIGNIFICANCE IN CROP PROTECTION
Authors: HAYES J. D. , PFEIFFER R. K. , RANA M. S. 
Published: July 2006

Summary. The response of eleven barley varieties to DDT and barban was assessed in field and glasshouse trials. Chlorosis following the application of DDT and minimal doses of barban is an all‐or‐nothing effect, whereas in apical inhibition there are several degrees of resistance. The criteria used to assess the eflect of barban on apical inhibition were fresh weight of seedlings, fertile tiller production at maturity and visual estimates of damage at the seedling stage and at maturity. Inheritance studies showed that resistance to the chlorosis reaction of both DDT and barban is controlled by single recessive genes independently inherited.Resistance to apical inhibition, on the other hand, appears to be quantitatively inherited. When F2 and F3 segregating populations in the field were sprayed with barban, the proportion of resistant plants in successive generations was markedly increased.The authors conclude that collaboration between plant breeder and pest control specialists could lead to a far more efficient control of weed, pest and pathogen by the development of varieties of crop plants with a high degree of tolerance to the chemical employed, especially under conditions where selectivity is narrow and delicate, such as in the control of other monocotyledonous plants in cereals.
GRUNDSäTZLICHE UNTERSUCHUNGEN ZUR ANWENDUNG VON SIMAZIN UND ATRAZIN IN WINTERWEIZEN
Authors: HAFNER K. 
Published: July 2006

Zusammenfassung. In mehrährigen Feldversuchen zur Bekämpfung von Ackerfuchsschwanz (Alopecanus mytosuroides) zeigten Simazin und Atrazin nur eine geringe Selektivitätsschwelle gegenuüber Winterweizen. Im einzelnen ergaben sich folgende Ergebnisse: 1. Mit Aufwandmengen von 0,375–0,5 kg/ha Simazin bzw. 0,25–0,375 kg/ha Atrazin wurde eine zufriedenstellende Unkrauiwirkung bei guter Getreideverträglichkeit erzielt. 2. Bei unterschiedlicher Empfindliclikeit in den einzelnen Entwicklungsstadien erwies sich der Weizen im 3–4‐ Biattstadium am verlräglichsten. 3. Durch Trockenheit zum Behandlutigszetipunkt wurde die Wirkung unterbunden. 4. Frostgeschädigtes Getreide wies eine erhöhte Empfindlichkeit auf.Studies on the use of simazine and atrazine in winter wheat
THE EFFECT OF HERBICIDES ON THE RELATION BETWEEN COVER INDEX AND YIELD INDEX
Authors: RIEPMA P. 
Published: July 2006

Summary. The effect of herbicide application on the relation between first and total number of contacts using the point quadrat method was studied. It was found that none of the herbicides tested — paraquat, dalapon, disodium methylarsonate, cacodylic acid and amitrole — affected the relationship appreciably, although differences in control were obtained. It is concluded that once the relation between first and total contacts is established in a particular field, the percentage weed control can he obtained with first contacts only, and the percentage weed control for total contacts calculated if necessary.L'effet des herbicides sur la relation entre l'indice de couverture et le rendement
DIRECT‐DRILLING OF CEREALS AFTER USE OF PARAQUAT
Authors: JEATER R. S. L. , McILVENNY H. C. 
Published: July 2006

Summary. Cereal crops were grown at Jealott's Hill in 1962 and 1963 without cultivations, following the use, before drilling, of paraquat to kill unwanted vegetation. This investigation was extended with a series of trials at outside centres. Three trials with winter wheat were drilled in the autumn of 1963, two into pasture and one into stubble. Three barley trials were drilled into stubble in spring 1964.All the autumn trials and one spring trial compared direct‐drilling with normal cultivations at two levels of nitrogen. The other two spring trials compared rates and times of application of paraquat without any plough comparison.Individual trials showed significant yield differences between direct‐drilling and ploughing, but there was no consistent advantage in favour of either technique.Spraying in advance of drilling generally resulted in similar yields to spraying and drilling on the same day. Winter wheat drilled into pastures showed some retardation of spring growth when spraying and drilling had been carried out on the same day.When averaged over times of application, yields after spraying paraquat at 2 lb/ac were significantly higher than after 1 lb/ac.In the trials where two levels of nitrogen were included crops responded to an increase from 60 to 120 units nitrogen/ac as top dressing for winter wheat and from 60 to 90 units nitrogen/ac combine‐drilled for spring barley; the response was not always significant.Semis direct de céréales après application de paraquat
EFFECTS OF RATE OF FORMATION OF 2,6‐DICHLOROBENZONITRILE ON ITS TOXICITY TO PLANTS
Authors: MILBORROW B. V. 
Published: July 2006

Summary. The toxicity of thirty 2,6‐dichlorophenyl compounds to seven species of plant is recorded as log10 dose in μg of compound per cm2 of soil surface that reduces the growth of the young plants to 50% of controls during a 10‐day period (Growth Inhibition dosage 50% or GID50). The compounds are broken down in soil with the release of 2,6‐dichlorobenzonitrile; those that break down rapidly show a greater range of GID50 values than those that break down slowly. This change in selectivity was found to be related to the relative fresh weight growth rates of the different species.Effet de la vitesse déformation du 2,6‐dichlorobenzonitrile sur sa toxicité pour les plantesRésumé. La toxicité de trente dérivés du 2,6‐dichlorobenzonitrile vis‐à‐vis de sept espèces de plantes est exprimée par le log10 de la dose en μg de produit par cm2 (Growth Inhibition Dosage 50% ou GID50) qui réduit de 50%, par rapport aux témoins, la croissance de jeunes plantes pendant une durée de 10 jours. Les produits son t décomposés clans le sol avec libération de 2,6‐dichlorobenzonitrile. Ceux qui sont décomposés rapidement montrent une plus grande variation de la GID50 que ceux qui sont décomposés lentement. Cette variation dans la sélectivité est en relation avec les taux de croissance, exprimés en poids frais, des différentes espèces.Der Einfluss der Bildungsgeschivindigkeit von 2,6‐Dichlorbenzonitril auf seine Toxicität bei PflanzenZusammenfassung. Die Wirksamkeit von dreissig 2,13‐Dichlorphenylverbindungen gegenüber sieben verschiedenen Pflanzenarten wird als log10 Dosis in μg der betreffenden Verbindung pro cm2 Bodenoberfläche ausggedrückt. Dirser Giftgehalt reduziert das Wachstum der jungen Pflanzen zu 50% von dem der Versuchspflanzen in einer 10‐tägigen Zeitspanne (Growth Inhibition Dosage 50% oder GID50). Die Verbindungen werden im Boden abgebaut, indem 2,6‐Dichlorbenzonitril entweicht; die rasch abbaubaren Verbindungen zeigen einen grösseren Umfang von GID50 Werten als diejenigen, die langsamer zersetzt werden. Man fand, dass dieser Wechsel in der Selektivität in Beziehung stand zu den relativen Frischgewichtswachstumsraten der verschiedenen Pflanzenartea.
SURVIVAL OF SEEDS OF WILD OATS (AVENA FATUA L, AND AVENA LUDOVICIANA DUR.) AND CHARLOCK (SINAPIS ARVENSIS L.) IN SOIL UNDER LEYS
Authors: THURSTON JOAN M. 
Published: July 2006

Summary. Survival of wild oat seeds (mainly Avena fatua) under leys on clay soils was investigated in two field experiments. During the first year under ley the number of seeds decreased by 41 % and 86% respectively. Subsequent decreases were less, and after 5 years under ley there were still enough of the original seeds left to produce infestation of a cereal crop. These results suggest that a long ley is not an efficient way of eliminating wild oat seeds from soil, and that a 1‐year ley may be almost as effective as one of 5 years.When a ley was ploughed, the number of wild oats germinating decreased as the number of years under ley and the age of the seeds increased, but was scarcely affected by the weather. In contrast, charlock (Sinapis arvensis) germination did not decrease with increasing age of seeds up to 5 years, but was greatest in years with most rain during April and May.Survivance de semences de Folle Avoine (Avena fatua L. et A. ludovieiana Dur.) et de Moutarde des champs (Sinapis arvensis L.) dans le sol sous prairie temporaire
STUDIES ON WEED SPECIES OF THE GENUS POLYGONUM L.
Authors: HAMMERTON J. L. , STONE M. 
Published: July 2006

Summary. Seeds of Polygonum lapathifolium were collected from eight localities during 1962. Plants of these populations were grown in the field and sampled at fortnightly intervals during June and July 1964. There were significant differences between populations in dry weight, leaf area index and nitrogen content at all samplings, and populations also differed in date of flowering and in certain morphological feature. Smooth curves were fitted to some of the growth data, and an account of the fitting procedure is given. For comparison, certain growth functions were calculated from the smooth curves as well as from the observed data. The populations differed in relative growth rate, net assimilation rate, relative nitrogen absorption rate and in certain other calculated functions, A number of growth attributes were significantly correlated with the latitude, longitude or length of the growing season of the locality of origin, and it is tentatively suggested that the populations represent climatic ecotypes.Études sur des espèces de mauvaises herbes du genre Polygonum L. II. Variations physiologiques dans P. lapathifolium L.
STUDIES ON WEED SPECIES OF THE GENUS POLYGONUM L.
Authors: HAMMERTON J. L. 
Published: July 2006

Summary. Two experiments are described in which plants of Polygonum lapathifolium were grown with barley in small field plots and sprayed with 2‐(2‐4‐dichlorophenoxy)propionic acid (dichlorprop) at a range of dose rates. Counts of the number of living plants before spraying and at intervals after spraying enabled the progress of mortality to be followed and the final mortality to be calculated. Probit analysis showed that there were considerable differences in LD50 among five populations from different localities of origin. In a second experiment, in which P. lapathifolium plants were sprayed at three stages of growth, there were large differences in LD50 between two populations at all three stages of growth, but no consistent or regular trend in LD50 with stage of growth. Etudes d'espèces de mauvaises herbes appartenant au genre Polygonum L. III. Variations de la sensibilité de P. lapathifolium L. à l'acid 2‐(2,4‐dichlorophénoxy) propionique
THE FATE OF PARAQUAT APPLIED TO PLANTS
Authors: SLADE P. 
Published: July 2006

Summary. Paraquat dichloride was applied to maize, tomato and broad bean plants as droplets of an aqueous solution and analysed al intervals. It was shown to be degraded under some conditions, but the amount of degradation was least under conditions which would have been most favourable for metabolism of the chemical. The analytical results and results from cation‐exchange paper chromatography and thin layer chromatography showed that the degradation was caused by photochemical decomposition on the surface of the leaves of the plants, not by metabolism. The degradation was not observed in the dark, and only occurred to a significant extent in daylight in the summer.Two photochemical degradation products from methyl‐labelled paraquat‐14C dichloride, viz., 4‐carboxy‐l‐(methyl‐14C)‐pyridinium chloride and methylamine‐14C hydrochloride, were isolated from plants sprayed with the herbicide.Le devenir du paraquat dans les plantes traitées
THE ABSORPTION AND TRANSLOCATION CHARACTERISTICS OF SEVERAL PHENOXYALKYL ACID HERBICIDES IN BIGLEAF MAPLE*
Authors: NORRIS L. A. , FREED V. H. 
Published: July 2006

Summary. Studies of the influence of formulation, degree of chlorination of the benzene ring and structure of the side chain of some phenoxyalkyl acid herbicides on absorption and translocation were made in a woody plant, Acer macrophyllum Pursh. In an experiment in which the leaves were treated with 2,4‐D or 2,4,5‐T as the acid, triethanolamine salt or 2‐ethylhexyl ester formulations, it was found that absorption increased with decreasing polarity of the molecule. The lower relative mobility of the ester formulations was offset by their greater absorption which resulted in greater accumulation in the roots when compared with the other herbicides. In treatments where dichlorprop or fenoprop formulated as the 2‐ethylhexyl esters were applied, a definite effect of chemical structure was observed on both absorption and translocation. The results of these tests and their implications in the response of big leaf maple are discussed.Caractères de l'absorption et de la migration de quelques herbicides du groupe des acides phénoxyalkyles dans l'érable a grandes feuilles Acer macrophyllum Pursh.
STUDIES OF THE RESPONSE OF PLANTS TO ROOT‐APPLIED HERBICIDES
Authors: LYNDSAY RUTH V. , HARTLEY G. S. 
Published: July 2006

Summary. Applications of several herbicides ‐were made to roots and to the bases of shoots of peas, cucumber, mustard and barley grown in soil, sand or water culture.Localized applications (variation horizontal) of atratone and MCPA to roots of peas and barley in soil produced effects similar to those observed in water euluire, described in Pan I. Airatone killed the plants whether available to the whole or to only a portion of the root system whereas MCPA affected only the roots with which it was in direct contact, and growth continued when a portion of the root system was in herbicide‐free environment.In water culture, MCPA was more effective when applied to the lower (younger) roots with the upper (older) roots kept dry than when twice the concentration was applied evenly to the whole root system in water. When all the roots were kept wet the effect of application to the upper roots was greater than the effect of application to the lower roots. The response of plants to atratone was not appreciably altered whether applications were made to the upper or lower parts of the root system in water culture. Variations in water level had little effect.Even when the herbicide solution was confined to the stem or hypocotyl, atratone and DNOC were little, if any, less effective than when applied to roots. MCPA, both as ester and sodium salt, was significantly less effective.Partial replacement of solution in the root zone by sand and air did not reduce the activity of atratone at a given concentration. Similar replacement in the zone of the stem or hypocotyl greatly reduced the effectiveness of all herbicides. When sand of low water content was used, atratone and MCPA‐sodium became quite ineffective via the stem, but DNOC and MCPA‐ethyl ester remained active.Études sur les réactions de certaines plantes á des herbicides appliqués aux racines II. Observations nouvelles sur l'effet de l'application localisée.
STRUCTURE‐ACTIVITY RELATIONSHIPS OF ALKYL‐ PHENOL ETHYLENE OXIDE ETHER NON‐IONIC SURFACTANTS AND THREE WATER‐SOLUBLE HERBICIDES
Authors: SMITH L. W. , FOY C. L. , BAYER D. E. 
Published: July 2006

Summary. Several alkylphenol ethylene oxide ether non‐ionic surfactants were tested in aqueous foliar sprays with dalapon, amitrole and paraquat for (heir enhancement of phytocidal activity against Zea mays L. With three homologous series of surfactants studied (octyl‐, nonyl‐ and laurylphenol types), the herbicide, the surfactant concentration and the hydrophilic constitution (ethylene oxide content) of the surfactant molecule all markedly influenced maximum toxicity. Smaller apparent differences in effectiveness were also attributable to the hydrophobic (alkylphenol) portion of the surfactant. The results arc discussed in relation to possible cuticle‐spray solution interactions and their influence on herbicide penetration.Relations entre la structure et l'activite de produits tensio‐actifs non ionigues, a base d'éther d'oxyde éthylénique et d'alkylphénol, en présence de trois herbicides hydrosolubles
A NEW TECHNIQUE FOR THE ACCURATE AERIAL APPLICATION OF HERBICIDES TO DRAINAGE CHANNELS WITH NEGLIGIBLE SPRAY DRIFT
Authors: ROBSON T. O. , LITTLE E. C. S. , JOHNSTONE D. R. , HILL R. F. 
Published: July 2006

Summary. Difficulties of access met with in Britain when applying dalapon to emergent water weeds in drainage channels led to work starting in 1964 on the development of a method of accurate aerial application of aqueous solutions of herbicide. The narrow, sinuous nature of the targets and the proximity of susceptible crops made it necessary to minimize spray drift and maintain a constant height and a slow speed. Nozzles designed to give large droplets were tested for droplet size and distribution. Selected nozzles were then tested from a helicopter in the field and the effect of their spray characteristics on the biological performance of dalapon was assessed. No daman occurred as a result of spray drift and satisfactory control of Phragmites communis, Typha angustifolia and T. latifolia was achieved with a lower dose of dalapon in a lower volume of spray than previously considered necessary for ground applications.Une nouvelle technique pour l'application précise d'herbicides par voie aérienne sur les canaux de drainage, avec des risques négligeables d'entrainement
COMPARISION OF RATES OF PARAQUAT PRIOR TO DIRECT‐DRILLING CEREALS
Authors: JEATER R. S. L. , LAURIE D. R. 
Published: July 2006

Summary. Trials were conducted in East Anglia to compare direct‐drilling following paraquat at 1 and 2 lb/ac with normal cultivations for both winter wheat and spring barley. The three treatments were compared at two levels of nitrogen.With direct‐drilled winter wheat, yields were higher after using paraquat at 2 lb/ac and at this rate there was little difference between direct‐drilling and normal cultivations when 100 units of nitrogen were applied in spring. When only 50 units were given the results were more variable, with direct‐drilling significantly outyielding normal cultivations in one trial, being outyielded in another and showing no difference in the third.Yields of spring barley were slightly higher after paraquat at 2 lb/ac as compared with 1 lb/ac, but not significantly so. The time of application of paraquat influenced yield; when applied in December yields from direct‐drilling and normal cultivations were similar, but when applied in February higher yields were recorded with normal cultivations.Comparaison des doses de paraquat a utiliser avant un semis direct de dreales
FLUCTUATIONS IN THE CHEMICAL COMPOSITION OF TWO LAKEWEEDS FROM NEW ZEALAND
Authors: FISH G. R. , WILL G. M. 
Published: July 2006

Summary. The mineral content of Elodea canadensis and Lagarosiphon major growing in two lakes near Rotorua showed seasonal variation and was influenced by the nutrient status of the water. Large quantities of L. major occur in Lake Rotorua and the average mineral content found was 3·9% N, 0·5% P, 2·6% K and 0·7% Mg (dry‐weight basis), a level which indicates potential commercial value.Variations de la composition chimique de deux mauvaises herbes aquatiques des lacs de Nouvelle‐Zélande
STUDIES ON WEED SPECIES OF THE GENUS POLYGONUM L.
Authors: HAMMERTON J. L. 
Published: July 2006

Summary. Seeds ni Polygonum lapathifolium from several sources or after certain treatments were subjected to various periods of moist chilling and then incubated for 3 weeks, during which time the numbers that germinated were recorded.Populations from different localities differed in both seed weight and in the response of the seeds to chilling, but no relationships between the response and the environment of the locality of origin were found. Seeds from individual plants and from single inflorescences within populations also varied in both seed weight and germination with and without chilling. Application of dichlorprop to the parent plants was found to affect seed weight and % germination, the effect varying with both population and dose.Etudes sur des espèces de mauvaises herbes du genre Polygonum L.IV. Variations du poids et des modalités de germination des semences chez P. lapathifolium L.
UNTERSUCHUNGEN ZUR KONKURRENZWIRKUNG VON KULTURPFLANZEN UND UNKRAUTERN AUFEINANDER
Authors: KOCH W. 
Published: July 2006

Summary. Pot experiments on the competitive effects of charlock (Sinapis arvensis L.) on oats and wild oat (Avena fatua L.) on barley had the following results:(1) During the period up to tillering there was an appreciable effect of the weeds on crop growth with depression in plant weight of 10–15% from that in the absence of weeds.(2) The greatest competitive effect occurred up to the middle of shooting of the cereals, when there were depressions in plant weight of 25–32%.(3) After this stage, the competitive effects of the weeds were much less in pots with a high nutrient level, and at low nutrient level there was almost no competitive effect.(4) The reduction in growth at the time of weeding was somewhat less at the low nutrient level than at the high nutrient level, and it is concluded that at the high level the competitive ability of the weeds was favoured more than that of the cereal crops.(5) The cereals were not able to overcome the initial damage caused by the weeds even when the weeds were removed at the beginning of tillering. A partial recovery did how ever occur at the high but not at the low nutrient level.(6) Both combinations, oats with charlock and barley with wild oat, behaved similarly, but some differences could be observed. Compétition entre plantes cultivées et mauvaises herbes II. Action des mauvaises herbes annuelles sur les céréales
EFFECTS OF WEED CONTROL AND NITROGEN APPLICATION RATE ON THE YIELD AND NTTROGEN CONTENT OF KALE
Authors: HAMMERTON J. L. 
Published: July 2006

Summary. The experiments reported show that weed competition throughout growth reduced kale yields by up to 89%. Competition until the 4‐leaf stage reduced yields by about 12%. Application of nitrogen had little effect on the actual loss of yield. The same yield could be obtained by controlling weeds from emergence and giving little nitrogen, or by delaying weed control until the 4‐leaf stage and giving a higher level of nitrogen, but kale crops that had suffered weed competition until the 4‐Ieaf stage appeared to be incapable of achieving the same yield as crops clean‐weeded from emergence. Data on nitrogen percentage and content suggest that competition between weeds and kale was not solely for iEffets du desherbage et du taux de fertilisation azoiée sur le rendement et la teneuren azote du chou fourrager