bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of asulam on two Lolium perenne swards containing Rumex obtusifolius
Authors: OSWALD A. K. , HAGGAR R. J. 
Published: July 2006

Summary:The effects of asulam applied in September 1970 at 0.55, 1.12 and 2.24 kg a.i./ha on Rumex obtusifolius (L.), Lolium perenne (L.), Other grasses and Trifolium repens (L.) growing in two swards in Wales were investigated. Good short‐term control of Rumex was achieved by all rates of asulum although regeneration was occurring by the spring following treatment. Dry matter yields of L. perenne were slightly lowered by 2.24 kg a.i./ha 6 weeks after spraying but production in the spring following treatment was substantially greater than on untreated plots. Poa trivialis (L.) and Agrostis stolonifera (L.) were substantially reduced but invasion of the bare spaces by P. trivialis and P. annua (L.) seedlings tended to mask the success of this control. No harmful effects on T. repens were recorded.
Effects of some phenylurea herbicides on photosynthesis of two wheat varieties
Authors: Van LEEUWEN P. H. , Van OORSCHOT J. L. P. 
Published: July 2006

Summary:Photosynthesis in the shoots of winter wheat (Triticum aestivum L.) was inhibited by certain phenylurea herbicides applied via the nutrient solution. Recovery from this inhibition after short treatments was used as a measure of the rate of inactivation of these herbicides in the leaf tissue of a variety tolerant to metoxuron (Caribo) and of a less tolerant variety (Manella). The introduction of chlorine atoms into fenuron greatly reduced the rate of inactivation in both varieties, whereas that of a methyl or butoxy group had little or no effect. Metoxuron was inactivated more readily than chlortoluron and both compounds were inactivated more rapidly in Caribo than in Manella.
Problems of herbicide assessment in peanuts in Jamaica
Authors: HAMMERTON JOHN L. 
Published: July 2006

Summary:Delays of 40 or 60 days in weeding peanuts (Arachis hypogaea L.) gave lower yields and fewer pods per plant but did not affect seed number per pod. Yield, pod number per plant, seeds per pod and mean weight per seed were all less in unweeded plots.In three herbicide trials crop yields were not closely correlated with crop vigour scores made several weeks before crop maturity, or with weediness scores. Correlations between yields and weed dry weights were better, but certain high‐yielding herbicide treatments gave poor weed control and in some cases had low crop vigour scores. Most yield differences reflected differences in pod number per plant, with additional smaller compensating or additive effects on the other components. Certain herbicides apparently gave high mean seed weights without diminishing seed numbers per pod. Pre‐emergence alachlor was the most promising herbicide, combined with preplant incorporated vernolate if nutgrass was serious. Napropamide and metobromuron merit further testing.
Effect of annual ryegrass (Lolium rigidum Gaud.) on yield of wheat
Authors: REEVES T. G. 
Published: July 2006

Summary:The effect of five densities of annual ryegrass (Lolium rigidum Gaud.) on the growth, moisture usage and grain yield of wheat at three sowing times was determined in the field. The presence of ryegrass reduced wheat dry matter production and grain yields by decreasing fertile tiller and fertile spikelet production. Ryegrass was more competitive in the later sown crops and its effect on wheat grain yield was directly proportional to the square root of its density. The relationship between ryegrass density and wheat yield reduction is quantitatively described.
Factors affecting dormancy and germination of seeds of Eichhornia crassipes (Mart.) Solms from the Nile
Authors: OBEID M. , el SEED M. TAG 
Published: July 2006

Summary:E. crassopes requires specific conditions for germination. The best laboratory germination was in clay soil, rich in organic matter, under less than 3 cm depth of water, in light. There are interactions with water depths, soil type, organic deposits, light and temperature.Storage conditions of seeds before germination affect the results. Wetting, drying and re‐wetting gave quickest, and complete germination. After 2 years dry‐storage, 78% of the seeds were still viable.
A study of assimilation and translocation inCuscuta hyalinaHeyne ex Roth.,Orobanche ramosaL. andStriga hermonthicaBenth.
Authors: ISMAIL A. M. A. , OBEID M. 
Published: July 2006

Summary:Quantitative determinations of chlorophyll showed thatCuscuta hyalina and Striga hermonthica possesschlorophyll. No trace of chlorophyll was found in Orobanche ramosa. Autoradiographic evidence showed that both radiocarbon and radiophosphorous moved from host to parasite in alt three species. Photosynthesis occurs in S. hermonthica when the parasite is isolated from its host. The adventitious roots of S. hermonthica and O. ramosa appear to be functional in absorbing a proportion of the required inorganic substances and water. S. hermonthica is a hemiparasite,O. ramosais a holoparasite butC. hyalinais best described as a partial parasite.
Cyanazine metabolism in corn, fall panicum, and green foxtail*
Authors: KERN A. D. , MEGGITT W. F. , PENNER DONALD 
Published: July 2006

Summary:The metabolism of cyanazine (2‐chloro‐4‐(1‐cyano‐1‐methyl‐ethylamino)‐6‐ethylamino‐ 1,3,5‐triazine) by corn (Zea mays, L.), fall panicum (Panicum dichotomiflorum Michx.), and green foxtail (Setaria viridis L.) was compared. Cyanazine metabolism by plants at the four‐leaf stage was examined by thin‐layer chromatography following foliar or root treatments with 14C‐cyanazine. Five days following foliar 14C‐cyanazine applicalion, fall panicum and green foxtail contained a larger number of water‐ and chloroform‐soluble metabolites than corn, whereas, following root treatment, the opposite was true. Corn rapidly hydrolysed the nitrile group and hydroxylated the two‐position on the triazine ring. Accumulation of the dealkylated cyanazine was evident in green foxtail, the most susceptible of the species studied. Metabolism of cyanazine supplied to the roots appeared to differ from foliar treatments in the weed species as more unchanged cyanazine was recovered. Rapid metabolism of cyanazine by corn roots provided evidence for an active cyanazine detoxication mechanism in the roots.
Factors that influence the persistence of TCA in soil
Authors: McGRATH D. 
Published: July 2006

Summary:The persistence of TCA in soil was examined using the pyridine‐alkali colorimetric procedure. Loss of TCA was essenlially similar when determined by colorimetry, chloride release or bioassay.Persistence of TCA when incubated with soil at 25°C or sprayed on the soil surface in the field was slightly influenced by soil type.Degradation of TCA occurs largely by microbial action after a lag phase. Soils treated with TCA acquire the ability to degrade further additions of ihe compound without a lag phase. The three soils examined still possessed this ability to differing extents 32 months after they had been sprayed once with TCA at the rate of 22.4 kg/ha. In one experiment the persistence of TCA was shortened appreciably in a plot that had twice previously been sprayed with TCA.
Weed competition in spring‐planted raspberries
Authors: LAWSON H. M. , WISEMAN J. S. 
Published: July 2006

Summary:Spring‐planted raspberries (Rubus idaeus L. cv. Malling Jewel) were exposed to competition from annual weeds for various lengths of time during the first growing season. Weeds germinating following crop planting in late March had no effect on numbers of new canes produced provided weed removal occurred by early June. The importance of preventing competition from these weeds during the critical period of cane emergence (June/July) was demonstrated. Dense weed cover reduced cane growth and, if weeds were left beyond late June, caused considerable mortality of planting material. Weed growth also frequently reduced cane height.In the second year, all plots were maintained free of weeds. Fruit yields showed effects of weeds similar to or greater than those indicated by total cane growth in the previous year. Height of new canes was unaffected by previous weeding treatments, but the numbers of new canes produced continued to show severe effects of initial competition from weeds.Allowing further weed growth to develop after initial weeding had no additional effect on crop survival or cane numbers in the first year. In one experiment, however, a reduction in cane height due to weeds germinating in June was followed in the second year by a reduction in the numbers of new canes produced.
Seasonal activity of EPTC for Cyperus rotundus L. control in a tropical climate*
Authors: WILLIAM R. D. , WARREN G. F. , GIORDANO L. B. 
Published: July 2006

Summary:Four experiments were conducted at six week intervals to determine the seasonal activity and persistence of soil‐incorporated EPTC (5‐ethyl N,N‐dipropyl(thiocarbamate)) for Cyperus rotundus L. control and tolerance of okra (Hibiscus esculentus L.), cucumber (Cucumis sativus L.), lettuce (Lactuca sativa L.), red beet (Beta vulgaris L.) and carrot (Daucus carota L.) during the dry and wet seasons in Viçosa, Brazil. Satisfactory control of C. rotundus was obtained at 2 kg/ha EPTC during the dry season and 4 kg/ha or more during the wet season. Only red beet and carrot tolerated these doses of EPTC when the crops were planted five days after application. However, selective control of C. rotundus was obtained when the planting date of lettuce was delayed for three or six weeks after EPTC application. EPTC controlled C. rotundus at half the dose that was required to control three species of annual grass that germinated near the soil surface. EPTC persisted longer when applied to air dry soil and incorporated with a rototiller than when incorporated into moist or wet soil.
Uptake and translocation of some pesticides by hypocotyls of radish seedlings
Authors: SHONE M. G. T. , WOOD ANN V. 
Published: July 2006

Summary:Some of the factors affecting absorption and translocation of pesticides by the hypocotyls of intact radish (Raphanus sativus, L., cv. Black Spanish) seedlings have been studied, particular attention being given to the triazine herbicides simazine, atrazine and atraton. Uptake and translocation appear to be largely passive processes and by contrast with foliar absorption seem to be unaffected by humidity, con‐centration, light and by the aqueous solubilities of the compounds. Diffusion across the tissues of the hypocotyl, rather than rate of transpiration, appears to determine the rate at which atrazine and simazine are translocated to the cotyledons. For several pesticides there is a qualitative relationship between the percentages of the compounds translocated to the upper portion of the shoots and their partition coefficients in oil/water systems. In conclusion, some consideration is given to the relative importance of uptake by roots and shoots under field conditions.
Sugarbeet tolerance of post‐emergence applications of desmedipham and ethofumesate*
Authors: ESHEL Y. , SCHWEIZER E. E. , ZIMDAHL R. L. 
Published: July 2006

Summary:Tolerance of sugarbeet (Beta vulgaris L.‘Mono‐Hy Al') to post‐emergence treatments of ethofumesate [(±)2‐ethoxy‐2,3‐dihydro‐3,3‐dimethylbenzofuran‐5‐yl‐melhansulfonate] and desmedipham [(3‐ethoxy‐carbonylamino)phenyl‐N‐phen‐ylcarbamate] was studied in the glasshouse and in the field at several growth stages. The response of sugarbeet to these herbicides was dependent on the growth stage of the plants and the amount of desmedipham in the mixture. Foliar growth was suppressed most when the herbicides were applied at the cotyledon stage; however, recovery from herbicide injury was rapid. Tolerance of sugarbeet increased considerably from the cotyledon stage to the six‐leaf stage. At equivalent herbicide rates, sugarbeet were more tolerant to ethofumesate than desmedipham and their response to mixtures of the herbicides was governed mainly by the rate of desmedipham. Root yields were reduced significantly by the herbicides only when sugarbeet were treated in the cotyledon stage with mixtures that contained 1.12 kg/ha of desmedipham.
The relationship between CO2 assimilation and the metabolism of bentazone in wheat plants
Authors: RETZLAFF G. , HAMM R. 
Published: July 2006

Summary:The assimilation of CO2 by wheat plants after treatment with various amounts of bentazone was investigated. Maximum inhibition of assimilation always occurred at the same time after treatment irrespective of the amount of bentazone applied. The reduction in CO2 assimilation rate was correlated with the uptake of active ingredient in the leaf tissue. Assimilation increased again, when the concentration of bentazone inside the leaf dropped as the results of metabolism to hydroxybentazones. The toxicity of 6‐ and 8‐hydroxybentazone to sensitive mustard plants was lower than that of the parent compound. It is suggested that hydroxylation is a step in the detoxification of bentazone.
The biology of Bassia birchii (F. Muell.) F. Muell.
Authors: AULD B. A. 
Published: July 2006

Summary:The native perennial shrub, Bassia birchii. occurs as a weed over large areas of semi‐arid eastern Australia. Its germination requirements and seedling growth were investigated and related to field observations and to possible means of control. Seeds cannot germinate until the woody fruit has broken down. Laboratory experiments showed that seeds would germinate throughout the year with most germinating at autumn and spring temperatures. Seedling deaths in the field are attributed to poor root growth, before the effects of water stress occurs. The spasmodic appearance of Bassia birchii infestations, particularly after droughts, is related to the dependence on the death of mature plants to provide propagules and fruit breakdown for germination. The unpredictable infestation pattern and the early development of spined fruits and basal buds on seedlings hinder control. Short period rotational or strategic grazing are suggested as possible means of control of seedlings in areas where perennial pastures can be established.
The selectivity of methabenzthiazuron between barley, perennial ryegrass and Poa trivialis
Authors: BLAIR A. M. , DRENNAN D. S. H. , HOLLY K. 
Published: July 2006

Summary:In field experiments methabenzthiazuron at 1.1 kg ai/ha applied pre‐emergence gave good control of Poa trivialis L. in perennial ryegrass S23 which was undersown in spring barley (Zephyr); no significant damage to barley or perennial ryegrass resulted from 2.2 kg ai/ha. However this dose applied when barley had three to four leaves decreased the subsequent barley yield.In pot experiments in the glasshouse methabenzthiazuron was active mainly due to uptake through the soil. Much greater damage to barley and perennial ryegrass resulted when herbicide‐treated soil was placed below seed level than above the seed. The difference was less marked with P. trivialis. The latter started to develop secondary roots near the soil surface earlier than either perennial ryegrass or spring barley.
The taxonomy and evolution of weeds
Authors: McNEILL J. 
Published: July 2006

Summary:Taxonomy describes and classifies (i.e. maps) the diversity of nature. The most useful classifications are those that permit the delimitation, and subsequent identification, of species in such a way that they exhibit genetic differences and ecological preferences. However, all classifications have limitations for weed scientists. Genetic variation within species may be just as important as differences between species to the development of weed control practices. Because traditional concepts, such as species, variety and ecotype, cannot fully reflect the products of evolutionary processes, alternative taxonomic or para‐taxonomic representations of variation are considered. The dependence of plant nomenclature on these inherently limited taxonomic concepts is also discussed, and ways are suggested of minimizing the resultant degree of instability in the scientific names of weeds. The evolutionary responses of weeds to changing conditions suggest that although selection within populations is important, changes in the species composition of a weed flora may be a more common response to selection. Recombination through hybridization can be particularly significant, especially in the evolution of weeds which are genetically close to the crop species.
Ein Vergleich von Biotests mit chemisch—analytischen Methoden zum Nachweis von Atrazin, 2,4—D, DNOC und Napropamid im Boden
Authors: HURLE K. 
Published: July 2006

Zusammenfassung:Der Abbau von Atrazin (2‐Chlor‐4‐äthylamino‐6‐isopropylamino‐s‐triazin), 2,4‐D (2,4‐Dichlorphenoxyessigsäure), DNOC (4,6‐Dinitro‐o‐kresol) und Napropamid [2‐(α‐Naphtoxy)‐NN‐diäthylpropionamid] im Boden wurde mit chemisch‐analytischen Methoden und mit Biotests verfolgt und die Ergebnisse miteinander verglichen. Der biologische Nachweis erfolgte für Atrazin mit Hirse (Sorghum‐Sudangras‐Hybride) in einem Gewächshaus‐Test, für 2,4‐D und DNOC mit einem Kressewurzeltest (Lepidium sativum L.), und Napropamid wurde mit einem Haferwurzeltest (Avena sativa L.) nachgewiesen. Der instrumentelle Nachweis wurde für Atrazin, 2,4‐D und Napropamid gaschromalographisch und für DNOC kolorimetrisch durchgeführt.Die für die Herbizide typische Abbaukinetik konnte durch die Biotests nachgewiesen werden, der quantitative Nachweis war jedoch nicht befriedigend. Bei Atrazin und Napropamid wurde durch die Biotests ein schnellerer Abbau und bei 2,4‐D und DNOC geringere Anfangskonzentrationen als durch die instrumentellen Methoden angezeigt. Mögliche Ursachen für die Abweichungen werden diskutiert und aus den Ergebnissen gefolgert, dass quantitative Aussagen mit Biotests erst dann gerechtfertigt sind, wenn ihre Qualität mit bewährten chemisch‐analytischen Methoden überprüft worden ist.
Studies on the mode of action of asulam in bracken (Pteridium aquilinum L. Kuhn) II. Biochemical activity in the rhizome buds
Authors: VEERASEKARAN P. , KIRKWOOD R. C. , FLETCHER W. W. 
Published: July 2006

Summary:The effect of asulam (methyl (4‐aminobenzenesulphonyl) carbamate) on the synthesis of RNA and protein was investigated in bracken sporeling plants and excised rhizome bud tissue. Foliage application of asulam (4.4 kg/ha) reduced the RNA levels in frond buds and young fronds within 3 days, while protein levels were significantly reduced after 14 days. A significant reduction in respiratory activity of buds was observed after 2 weeks, the level of inhibition being 54% after 8 weeks. During a 3‐h incubation period, O2 uptake by excised bud issue was stimulated by 5 and 10 ppm asulam and inhibited by higher concentrations; 32P uptake was inhibited at all concentrations. Asulam (5 ppm and above) inhibited bud growth and reduced RNA and protein levels in incubated buds (20 h at 30°C), and the incorporation of [14C]orotic acid into RNA and [14C]leucine into protein. Reduction of RNA levels and inhibition of [14C]ladenine incorporation into RNA in buds occurred entirely in the ribosomal and supernatant fractions of the cellular extract. Inhibition of RNA synthesis by asulam (50 ppm) as measured by [14C] orotic acid incorporation into RNA was completely antagonized by CEPA (3‐chloroethylphosphonic acid) (50 ppm) and partially by 2,4‐D (2,4‐dichlorophenoxyacetic acid) (50 ppm) and GA (Gibberellic acid) (50 ppm). These results suggest that the interference of asulam with RNA and protein synthesis at the metabolically active sinks (rhizome buds) could be one of its major mechanisms of action in bracken.
Paraquat, diesel oil and kerosene for ratoon clearing of pineapple
Authors: LEE S. A. 
Published: July 2006

Summary:Three chemical methods of clearing pineapple ratoons were compared with the traditional method of cutting and burning after the plants have dried. The best chemical treatment was paraquat at 0.84 kg ha−1 which gave full scorching at leaves on 92% of plants so that they could be easily burnt 3 weeks after treatment. Plants sprayed with diesel oil or kerosene at 570 1 ha−1 could be satisfactorily burnt after 9 weeks compared with 12 weeks required for satisfactory burning with the traditional method.
Longevity of shattercane seed in soil across Nebraska*
Authors: BURNSIDE O. C. , WICKS G. A. , FENSTER C. R. 
Published: July 2006

Summary:Longevity of shattercane [Sorghum bicolor (L.) Moench] seed buried 22 cm deep in soil at three locations across Nebraska, U.S.A. was followed for 14 years. Shattercane seed lost viability more quickly when buried in a Keith very fine sandy loam in western Nebraska (Alliance, average seed germination 21%) than in a Holdrege silt loam in central (North Platte, 37% germination) or in a Sharpsburg silty clay loam in eastern Nebraska (Lincoln, 38% germination) which were similar. The maximum survival of the open‐panicle shattercane biotype, with glumes tightly enclosing the seeds, used in this study was 11, 12, and 13 years at Alliance, North Platte, and Lincoln, Nebraska, respectively.
Some effects of competition between Emex australis and E. spinosa
Authors: WEISS P. W. 
Published: July 2006

Summary:When plants of Emex australis Steinh. and E. spinosa Campd. were grown in pots in monoculture or in competition, there was greater seedling mortality in E. australis. In competition with E. spinosa, E. australis was later‐flowering and had lower seed, leaf, root and total dry weights. However, in E. spinosa leaf, stem, seed and total dry weight were greater than they were in mono‐culture. The more bulbous root and more erect stems of E. spinosa may be linked with its greater competitive ability. Although at present much more restricted in occurrence in Australia than E. australis, the results suggest that E. spinosa will in time become the dominant species where the two occur together.
Chemical weed control in rainfed peanuts
Authors: HEGDE B. R. , VENUGOPAL N. , FRIESEN G. H. 
Published: July 2006

Summary:Field studies at Bangalore, India, demonstrated that benfiuralin, fluchloralin and profluralin were effective for the selective control of many weed species in field experiments with peanuts (Arachis hypogaea L.‘BH‐8‐18′). Trifluralin and dinitramine were effective against many weed species but reduced crop stand by about 10%. These two herbicides also reduced the incidence of leaf spot disease (Cercospora arachidicola) and peanut pod yields were similar to clean weeded treatments. Bentazon was ineffective on most weed species and metribuzin was lethal to the crop. Alachlor, nitrofen and chloramben were only partially effective and would require supplemental hand weeding or mechanical tillage to obtain satisfactory weed control.
The effect of herbicides on respiration and transformation of nitrogen in two soils II. Dalapon, pyrazone and trifluralin
Authors: DAVIES H. A. , MARSH J. A. P. 
Published: July 2006

Summary:The effects of dalapon, pyrazone and trifluralin at 100 ppm on carbon dioxide evolution and nitrogen transformation in two soils have been investigated in the laboratory. None of the herbicides had any adverse effects on carbon dioxide evolution or mineralisation of nitrogen. In Triangle soil (organic carbon 3.9%, pH 5.4) dalapon and pyrazone inhibited nitrification for at least 3 weeks. In Boddington Barn soil (organiccarbon 1.5%, pH 6.6) this effect was not observed. Dalapon degraded rapidly during the first 6 weeks, but pyrazone and trifluralin were more persistent.