bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECTS OF SUB‐LETHAL DOSES OF MCPA ON THE MORPHOLOGY AND YIELD OF VEGETABLE CROPS
Authors: LETTUCE I. , WAY J. M. 
Published: July 2006

Summary. The effect of sub‐lethal doses of MCPA‐sodium on the growth, yield and marketability of summer cabbage lettuce was studied in seventeen replicated field experiments.Initial epinasty was produced by doses as low as 0.002 lb/ac a.e., and formative effects of the leaves developed at doses below 0.01 lb/ac. In plants treated at early or intermediate growth stages, two distinct types of formative effects occurred, With doses in the range 0.0025‐0.03 lb/ac, a zone of characteristic abnormal leaves developed. This reduced the marketability of the crop and the maturity was delayed, but the weight per plant at harvest was not affected. At higher doses these a abnormal leaves were not evident but the whole plant became distorted, growth was suppressed and few marketable plants were produced. In plants treated at the hearting stage, plant weight and maturity were not affected, but the marketability was reduced at doses of 0.01 lb/ac and above. The effects produced by MCPA in cos and curly crisp lettuce were compared with those produced in cabbage lettuce.
A COMPARISON OF METHODS OF RECORDING HERBACEOUS WEEDS IN WEED CONTROL EXPERIMENTS
Authors: RIEPMA P. , WENG WONG PHUI 
Published: July 2006

Summary. In herbicide studies close correlation between results given by the square quadrat method and by a point quadrat method for assessing the number and frequency of weed species was found. Marked correlations between the density obtained by the square quadrat and the cover and yield indices obtained by the point quadrat method were observed.Treatment discrimination using the point quadrat was as good as that obtained with the square quadrat and it is concluded that the point quadrat method is suitable for assessing weed control in low‐growing vegetation.Comparaison de méthodes de notation des mauvaises herbes herbacées dans les essais de désherbage
ESSAIS EN PLEIN CHAMP DE DESHERBAGE SELECTIF DES BETTERAVES PAR LE CHLORO‐AMINO‐PHENYL‐PYRIDAZONE (PCA)
Authors: LHOSTE J. , D'ILLE H. , CASANOVA A. , DURGEAT ET L. A. 
Published: July 2006

Résumé. Les auteurs poursuivant leurs études concernant les possibilités d'application de désherbants chimiques sélectifs en culture de betterave industrielle relatent les résultats qu'ils ont obtenus en utilisant dans ce but le chloro‐amino‐phénylpyridazone (PCA) associé ou non à la cyclo‐octyl‐diméthylurée (OMU).La méthode expérimentale est décrite en détail. L'appareil épandeur d'herbicide est le pulvérisateur logarithmique conçu par Dr H. G. van der Weij.Les résultats obtenus avec le PCA sont en accord avec ceux mentionnés par Fischer (1963). Le PCA n'est pas phytotoxique pour les betteraves, excepté pendant le stade dit‘cotylédons étalés'. Le mélange PCA + OMU est phytotoxique appliqué en post‐émergence.L'effet de ces deux herbicides est satisfaisant. La dose minimum de 2,5 kg/ha pour le PCA et celle de 1,6 kg/ha de PCA + 0,4 kg/ha d'OMU s'est révélée efficace dans les conditions de nos expérimentations.Feldversuche zur selektiven Unkrautbekämpfung im Zuckerrübenbau durch Chlor‐Aminophenylpyridazon
SELECTIVE CONTROL OF CHENOPODIUM ALBUM IN KALE WITH METHYLMERCAPTO TRIAZINES
Authors: BAKER G. , HOLMES H. M. , PFEIFFER R. K. 
Published: July 2006

Summary. Following the discovery by J. G. Elliott and T. I. Cox in 1961 of the specific selective properties of certain methylmercapto triazines for the control of Chenopodium album in kale (Brassica oleracea var. acephala), extensive investigations of this subject were carried out by the authors in 1962. The work resulted in a practical recommendation to British farmers in 1963.2‐Methylmercapto‐4‐methylamino‐6‐isopropylamino‐1,3,5‐triazine (G 34360) showed significantly higher selectivity than simetryne. The dose giving an optimum degree of selective control varied according to humidity and moisture. A dose of 4 oz/ac was sufficient for kale grown under moist conditions, while 6 oz/ac was required under condition of low rainfall and atmospheric humidity.The development stage of the kale was critical and the herbicide was sufficiently safe only when applied after the kale had three leaves. No differences in response were observed between marrow‐stem and thousand‐head kale. Volume rates from 10 to 80 gal/ac were compared, but no clear differences were found. Destruction sélective de Chenopodium album L. dans le chou fourrager avec les méthylmercaptotriazines
DORMANCY IN HOMERIA BREYNIANA (L.) LEWIS
Authors: PEARCE G. A. 
Published: July 2006

Summary. The variation in the percentage of dormant corms of Homeria breyniana between sites and years was shown for a 3‐year period. The highest dormancy count of 61 % was obtained at Wagin in 1959 while the lowest count of 1% was also obtained in 1959 at Muchea. It was demonstrated that soil surface cover plays an important part in corm dormancy. In 1961 the removal of the surface cover by burning almost eliminated dormancy. Removing the cover at three dates during the summer did not affect the germination of corms during the late autumn. Moreover, corms left in the soil throughout the summer exhibited no physiological dormancy in April. In laboratory tests the percentage germination steadily decreased as the test temperatures were reduced from 25 to 5° C. Soil temperatures follow a similar decline in Western Australia during April and May. Light rains of 12 and 14 points (100 points = 1 in.) gave a significant increase in soil moisture where the surface was bare. Sufficient moisture penetrated to cause a general germination of corms and this resulted in H. breyniana emerging on bare soil some 3 weeks earlier than where surface cover was present. The diurnal temperature range at this time was 54–68° F. The break of the season (the beginning of the growing season) did not occur until 17 days later, and the diurnal soil temperature range had dropped to 49–54° F. Corms subjected to germination tests at these two temperature ranges gave a 90% and 70% sprouting respectively. La dormance des bulbes de Homeria breyniana (L.) Lewis
A PRECISION SPRAYER FOR SMALL EXPERIMENTAL FIELD PLOTS*
Authors: GROVER R. , CLARKE H. 
Published: July 2006

Summary. Large‐scale field testing of herbicides nccessitales the use of small experimental plots. Most of the available small‐plot experimental sprayers do not have any mechanical control of the speed of the spray boom and thus depend on the speed of the operator or an pushed by or mounted on various types of vehicles. Inability to attain a desired speed of the spray boom over a short distance by mechanical means has hindered the development of a precise small‐plot sprayer. This problem was resolved by the attainment of the desired speeds prior to the release of the spray boom. The principal parts of the unit are: (1) speed control and drive mechanism with an endless cable running at speeds of 1, 2 and 3 miles/hour; (2) boom‐carrier which may be locked to the continuously running cable; (3) rotary gear pump; (4) pressure regulator; and (5) spray boom with two ‘even spray Teejet’ nozzles. The entire machine is 6 ft wide and 13 ft in length and sprays a plot 5 ft wide and 10 ft long. The unit is mounted on four wheels for transport from plot to plot. During its initial trials in the field, the unit has shown precision, accuracy and repeatability in small‐plot spraying, seldom attained by small‐plot sprayers. In addition the unit is simple in design and can be easily assembled by an experienced mechanic.Un pulverisateur de précision pour petites parcelles experimentales
UNTERSUCHUNGEN ÜBER DIE URSACHEN DES VERMEHRTEN AUFLAUFENS VON UNKRÄUTERN NACH MECHANISCHEN UNKRAUTBEKÄMPFUNGS‐MASSNAHMEN (NACHAUFLAUF)
Authors: MÜLLVERSTEDT R. 
Published: July 2006

Zusammenfassung. Investigations on the causes of increased emergence of weeds following mechanical weed control measuresUm den Grund für vermehrtes Auflaufen von Unkrautsamen nach mechanischen Unkrautbekämpfungsmassnahmen (Nachauflauf) zu finden, wurden die drei denkbaren Faktoren bei Avena fatua, Sinapis arvensis, Alopecurus myosuroides und Galium aparine untersucht. Das Licht war dabei ebenso ohne Einfluss wie die mögliche Verlagerung von Unkrautsamen durch das Eggen in keimgünstige Bodentiefen. Gegenüber dem Licht erwiesen sich die untersuchten Arten bei der Keimung indifferent. Beim Eggen wurden grössere Samen im Lehmboden vorzugsweise aufwärts, kleinere Samen dagegen abwärts bewegt, mithin entgegengesetzt zu den keimgünstigen Tiefen. Die mit dem Eggen verbundene Bodendurchlüftung führte dagegen im Vergleich zu den un‐belüfteten Kontrollen zu gesichertem Mehrauflauf, so dass die bessere Luftdiffusion in den durch Eggen gelockerten Boden als Grund für den Nachauflauf anzusehen ist.
ABSORPTION AND TRANSLOCATION OF RADIOACTIVE HERBICIDES IN SUBMERSED AND EMERSED AQUATIC WEEDS*
Authors: FUNDERBURK H. H. , LAWRENCE J. M. 
Published: July 2006

Summary. Absorption and translocation of labelled herbicides by a submersed weed, waterstargrass (Heteranthera dubia (Jacq.) MacM.) were studied. Autoradiographs showed that simazine (or the labelled carbon atom) and 2,4‐D‐butoxyethyl ester moved both from roots to shoots and from shoots to roots. Ametryne, prometryne, fenac and 2,4‐D (acid) moved to a slight extent from shoot to root, but no movement from root to shoot could be detected in the autoradiographs. However, counting data indicated that small amounts of these four compounds, not recorded on autoradiographs, may move from root to shoot. Radioassay did not detect diquat or paraquat movement to the roots or to the upper portions of the shoots, but the autoradiograph of one plant receiving a root application of paraquat showed slight movement into the lower portion of the stem.Absorption and translocation of labelled herbicides by an emersed weed, alligatorweed (Alternanthera philoxeroides (Mart.) Griseb.), were also studied. Darkening of film indicated that relative mobility of root‐applied herbicides was as follows: ametryne = fenac = prometryne = simazine>diquat = paraquat> 2,4‐D (acid) = 2,4‐D‐butoxyethyl ester. There was little movement of foliage‐applied simazine, ametryne and prometryne. There was slight downward movement of foliage‐applied fenac, diquat and paraquat, and considerable downward movement of 2,4‐D (acid) and 2,4‐D‐butoxyethyl ester, which accumulated in the nodal regions of the stem.Radiolabelled phosphorus moved in both directions in both plants and there was more movement in an upward direction in both species.Absorption et migration d'herbicides radio‐actifs dans des mauvaises herbes aquatiques immergées et émergentes
THE EFFECTS OF SUB‐LETHAL DOSES OF MCPA ON THE MORPHOLOGY AND YIELD OF VEGETABLECROPS
Authors: WAY J. M. 
Published: July 2006

Summary. The effects of sub‐lethal doses of MCPA‐sodium on the morphology and yield of red beet, turnip and onion and on the morphology of spinach were studied in field and glasshouse experiments. Epinastic responses of beet were seen at 0.003 lb/ac a.c., but no serious formative effects or yield reductions occurred below 0–07 lb/ac and plants were only killed by doses above 0–1 lb/ac. Spinach was affected at 0–06 lb/ac, the lowest dose used, but the plants were not killed at 0–33 lb/ac. Epinasty in turnip occurred at 0–002 lb/ac, and at 0–01 lb/ac many of the roots were abnormal, while spraying with 0–1 lb/ac and above resulted in severe distortion or death of the plants. Onion was the least affected of all the crops studied. When a welting agent was included in the spray epinasty occurred at 0–3 lb/ac, but there were no serious formative effects or yield reductions below 1–0 lb/ac. The symptoms of injury in onion were often transitory because the affected parts were replaced as the bulb developed.Effets de doses sub‐léthatles de MCPA sur la morphologie et If rendement des cultures légumiéres. V. Betteraves, Epinards, Navets et Oignons
OBSERVATIONS ON THE EFFECT OF HERBICIDES ON YOUNG COCONUTS
Authors: ROMNEY D. H. 
Published: July 2006

Summary. Phytotoxic effects of eight herbicides on young coconuts were assessed by recording visual symptoms of injury and growth following treatment. The growth‐regulators 2,4‐D, 2,4,5‐T and MCPB were lethal at the normal doses used for annual weed control. Dalapon at 5–9 lb/ac applied in 100 gal/ac of water caused yellowing and necrosis of the foliage, reduced growth, and sometimes killed the whole plant, while doses down to 2.2 lb/ac caused some fusion of the pinnae. Monuron at 3.2 and 6.4 lb/ac resulted in serious frond damage and reduced growth, and some frond injury occurred at 1–6 lb/ac. Diquat at 0.25–1.0 lb/ac and paraquat at 1.0–l.5 lb/ac caused extensive necrosis of existing fronds but there was no appreciable reduction in new growth. Amitrole produced considerable chlorosis both at 3.1 and G.3 lb/ac, but only the higher dose caused a reduction in growth.Essai d'herbicides sur jeunes cocotiers
HERBICIDAL EFFECTS ON CERTAIN SOIL MICROBIAL ACTIVITIES IN SOME BROWN SOILS OF SASKATCHEWAN
Authors: CHANDRA PURNA 
Published: July 2006

Summary. Amitrole, 2,3,6‐TBA, 2,4‐DB and di‐allate were applied at normal field rates to a loam soil in a preliminary study, The toxic effects, as measured by nitrification studies, persisted for 8 weeks after application. After a further 8 weeks this depressive effect was decreased.Residual effects were assayed by measuring the nitrification rate of soils following the application of the same four herbicides at two rates to four different soils. The residual effects of amitrole, di‐allate, 2,3,6‐TBA and 2,4‐DB were overcome 34, 28, 32 and 44 weeks respectively after treatment. Total microbial counts were also corelated with the nitrification rate of the soils. The trend of disappearance of the toxic effect of these chemicals was similar in all the soils in these laboratory investigations.Under field conditions the residual effect of amitrole, 2,3,6‐TBA and 2,4‐DB had disappeared by the end of 52 weeks, as far as could be determined by studies of nitrate production, ammonification and total counts of microorganisms. A second application of the chemicals 56 weeks after the initial treatment affected nitrification in the laboratory for only half as long, indicating adaptation of' the microorganisms to the herbicidesEffels des herbicides sur certaines activités des microorganismes du sol
ANALYTISCHE UNTERSUCHUNGEN VON TRIAZ1N‐HERBIZIDEN
Authors: STAMMBACH K. , KILCHHER H. , FRIEDRICH K. , LARSEN M. , SZÉKELY G. 
Published: July 2006

Zusammenfassung. Die vorliegende Arbeit beschreibt die analytische Reinheits‐prüfung einer Auswahl von Triazin‐Herbiziden am Beispiel von Atrazin, Atraton und Prometryn mit Hilfe der Dünnschicht‐ und der Gas‐Chromalographie. Investigations on the analysis of triazine herbicides
THE METABOLISM OF HERBICIDES*
Authors: BRIAN R. C. 
Published: July 2006

Summary. A knowledge of the metabolism of herbicides within plants is of importance in a number of ways. Thus, whilst governmental control of the toxicity of potential herbicides is being exercised by fixing acceptable levels of residues, information may also be required an the toxicity of their possible metabolites. This aspect is not pursued but metabolism of chemicals by plants is divided into that which: (1) militates against their efficiency (deactivation), (2) introduces useful biological properties, (3) is essential to their biological activity (activation).The metabolism of the important herbicides of each class is reviewed briefly and its effect on their use in the field described where possible. Emphasis, however, is given to the unique mode of action of the bipyridylium quaternary ammonium compounds—diquat and paraquat—as herbicides in the last class, depending for their activity on a reduction by the plant In toxic free radicals. Evidence for the participation of free radicals in their herbicidal activity is presented, and their physical and biological properties described. Physiological processes involved in this free radical production are discussed and also hypotheses concerning their mode of action.Le métabolisme des herbicides
THE INFLUENCE OF DALAPON ON GROWTH AND DEVELOPMENT OF AUTUMN‐SOWN SUGAR BEET*
Authors: ELLERN S. J. , MARANI A. 
Published: July 2006

Summary. In order to determine the phytotoxicity of dalapon—sodium to October‐sown sugar beet in southern Israel, a substantially weed‐free field was sprayed on three dates with 1·1, 2·2, 4·5 and 9·0 kg/ha a.e. Samples of beet were taken on five dates between February and July. The 9–0 kg/ha rate of dalapon caused a significant reduction in the weight of both roots and the other beet components. At 4·5 kg/ha phytotoxic effects were less marked. It is concluded that dalapon at rates lower than 4·5 kg/ha, applied between mid‐November and mid‐January, should be a safe treatment for October‐sown sugar beet where grasses rather than broad‐leaved weeds predominate.Effet du dalapon sur la croissame ei lé développement de la betterave sucrière semée en automne
THE EFFECT OF MCPA ON THE AMINO ACID AND SUGAR COMPOSITION OF VICIA FABA LEAVES
Authors: MacLEOD D. G. 
Published: July 2006

Summary. The effect of spraying Vicia faba leaves with 5000 ppm MCPA is described. Three to 4 days after spraying, a marked increase (× 5 approx.) was found in the concentrations of leucine iso‐leucine and valine in the leaves. No significant changes were detected in the other amino acids. Treatment with MGPA also caused a significant increase (× 4 approx.) in the glucose and fructose content of the leaves. Detached leaves (sprayed and unsprayed), when kept in a moist atmosphere for 3–4 days, exhibited very similar increases in amino acids and sugars to sprayed intact plants. Experiments using 14CO2 revealed that in short term photosynthesis (30 min) of sprayed and unsprayed plants, 80–90% of the radioactivity was incorporated in sucrose, with about 5% in each of glucose and fructose. Over photosynthelic periods of 4 days, glucose and fructose were found to be almost as heavily labelled as sucrose in sprayed plants, but in the controls the distribution of radioactivity was similar to that in short term photosynthesis. It is suggested that the build up of amino acids and sugars in plants treated with MCPA is due to an interruption of the translocatory flow from the leaves, and that this build up of metabolites may be a contributory factor in the toxic action of this herbicide.Effet du MCPA sur la composition en amino‐acides et en sucre des feuilles de Vicia faba
THE EFFECTS OF SUB‐LETHAL DOSES OF MCPA ON THE MORPHOLOGY AND YIELD OF VEGETABLE CROPS
Authors: WAY J. M. 
Published: July 2006

Summary. The effects of 2,4‐D, 2,4,5‐T, mecoprop and 2,3,6‐TBA were compared with those of MCPA on the morphology and yield of lettuce, cabbage, cauliflower, Brussels sprout, carrot, parsnip, French and broad bean, red beet, spinach, turnip and onion. Although the relativie phytotoxicity of MCPA, 2,4‐D, 2,4,5‐T and mecoprop varied according to the crop, the morphological abnormalities produced by the different compounds were essentially similar, except that in lettuce and cabbage sperilic foliar symptoms appeared to be associated with 2,4‐D. 2,3,6‐TBA caused less epinasty and usually fewer root and stem abnormalities, but in some crops, notably French and broad bean, red beet and spinach, it produced severe injury symptoms which were different from those produced by the other compounds.Effets de doses sub‐léthales de MCPA. sur la morphologie et le rendement des cultures légumirres VI. Comparaison avec le 2,4‐D, le 2,4,5‐T, le micoprop et le 2,3,6‐TBA
HERBICIDE MIXTURES FOR WEED CONTROL IN PEANUTS (ARACHIS HYPOGAEA L.), 1961–63*
Authors: HAUSER E. W. , PARHAM S. A. 
Published: July 2006

Summary. Comparative studies of herbicides and herbicide mixtures in peanuts (groundnuts) were continued at Tifton, Georgia, U.S.A., on Tifton loamy sand during 1961–63. When applied on a dry soil surface at the ‘cracking’ stage, certain mixtures which contained dinoseb as one component with 2,4‐DES, 2,4‐DEP, or DMPA as the Other component gave control of Digitaria sanguinalis (L.) Scop. and Richardia scabra St. Hil. for the entire growing season. However, on wet soils with no subsequent rain during the first weeks or with prolonged excess moisture, mixtures were not appreciably more effective than herbicides applied singly at standard rates. Where mixtures were applied on wet soil, herbicide effectiveness was improved by timely follow‐up sprays of dinoseb at 1.5 lb/ac.Timing of application was often critical for optimum weed control. The best time was when the peanuts were cracking the ground or when the first weeds were barely visible, whichever occurred first.Mixtures permitted the use of the lowest rate of each compound on the weeds for which it was most effective.A mixture of DMPA at 6 lb/ac 4—dinoseb at 3 lb/ac applied at the ‘ground‐cracking’ stage increased the average yield of peanuts.The mixtures evaluated had no effect on shelling‐%, % sound mature kernels (SMK), mean weight per nut, or % germination. Neither did they affect taste of the peanuts or other sensory. characteristics. However, preliminary chemical analyses indicated that peanuts treated with mixtures contained more linolein and less olein than did untreated peanuts.Essais d'herbicides et de mélanges herbicides pour le désherbage dans les arachides (Arachis hypogea L.), 1961–63
SOME EFFECTS OF THE NITROGEN SUPPLY ON THE GROWTH AND DEVELOPMENT OF ACROPYRON REPENS L. BEAUV.*
Authors: McINTYRE G. I. 
Published: July 2006

Summary. The influence of the nitrogen supply on the growth and development of quackgrass (Agropyron repens L. Beauv.) was investigated by growing plants in sand culture at nitrogen levels of 210, 10–5, 5.25 and 2.6 ppm in addition to constant levels of other basic nutrients.When these nutrient regimes were first applied the rate of leaf emergence showed a positive correlation with the nitrogen level. This effect, however, did not persist and the rate subsequently attained was similar at all levels of nutrition. Tiller emergence, on the other hand, was markedly dependent on the nitrogen supply and at 2.6 ppm N was almost completely suppressed. As a result of this effect the production of secondary rhizomes, i.e. those arising from tillers, was correspondingly reduced. There was, however, a slight increase in the number of rhizomes produced from buds on the parent shoot.At 2.6 ppm N the dry weight of the shoots was reduced by approximately 75% as compared with the highest nitrogen level but there was no significant reduction in the weight of the roots or rhizomes. The shoot/root ratio was thus considerably decreased at the lower ni trogen levels.By varying the nitrogen supply it was also possible to control quite precisely the behaviour of the rhizome buds. At 2.6 ppm and 10.5 ppm the buds ceased to grow when 2–6 mm in length, the size attained being determined by the nitrogen level. At 210 ppm, however, the onset of dormancy was eliminated and all of the buds grew out as lateral branches. Bud growth could also be induced at a low nitrogen level (5.25 ppm) by removing the rhizome apex.The significance of these results is discussed in relation to the ecology of the plant and to the problem of apical dominance.Influence de diverses dases d'azote sur la croissarce et le développent d'Agropyron repens L. Beauv.
NEBURON, A SELECTIVE HERBICIDE FOR USE IN TROPICAL LEGUMES
Authors: RIEPMA P. 
Published: July 2006

Summary. The effect of pre‐ and post‐emergence applications of neburon on the growth of Pueraria phaseoloides and Centrosema pubescens has been tested. Pueraria phaseoloides was adversely affectcd by both applications, seprately and combined, the effect being greater on a sandy soil than on a clay soil. Centrosema pubescens showed greater tolerance, and was little affected by post‐emergence treatment but pre‐emergence treatment showed some adverse effect.The check to growth of the legumes could be offset by increased rates of sowing. It appears that neburon might be suitable as a selective herbicide for application in tropical legumes.Le néburon, herbicide sélectif pour les cultures de légumineuses tropicales