bluuebunny/crossref_metadata_2025 huggingface dataset:
Thomas K. Pavlychenko: Pioneer Weed Experimentalist
Authors: Bubar Carol J. , Morrison Ian N.
Published: May 2019

Thomas Karp Pavlychenko's pioneering investigations on the root systems of crops and weeds and the results of his research on weed biology and ecology at the University of Saskatchewan in the 1930's and 1940's provided the foundation for many of the principles of modern weed science. His classical studies in which he quantified the distribution and length of roots of many plant species continue to be regarded as being of unsurpassed caliber. In addition to his work in the areas of crop ecology and plant competition, Pavlychenko is also noted for his many contributions relating to the cultural and chemical control of weeds. In this paper, a brief chronicle of Pavlychenko's life and major accomplishments during his remarkable career at the University of Saskatchewan and later with the American Chemical and Paint Company is presented.
Herbicide Effectiveness in Response to Season of Application and Shrub Physiology
Authors: Lanini W. Thomas , Radosevich Steven R.
Published: May 2019

The selectivity of five foliage-applied herbicides, 2,4-D [(2,4-dichlorophenoxy)acetic acid], dichlorprop [2-(2,4-dichlorophenoxy)propionic acid], glyphosate [N-(phosphonomethyl)glycine], fosamine [ethyl hydrogen (aminocarbonyl)phosphonate], and triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid}, applied at three phenological stages of development to five Sierran shrub species, deerbrush [Ceanothus integerrimusvar.californicus(Kell.) G. T. Benson.], greenleaf manzanita (Arctostaphylos patulaGreene), bearmat (Chamaebatia foliolosaBenth.), snowbrush ceanothus (Ceanothus velutinusDougl.), and whiteleaf manzanita (Arctostaphylos viscidaParry), was compared. Treatments in the summer and fall were less effective than spring applications. Periods of herbicide susceptibility generally corresponded to times when moisture stress was low and photosynthesis was high.
Allelopathic Potential of Wheat (Triticum aestivum) Straw on Selected Weed Species
Authors: Steinsiek James W. , Oliver Lawrence R. , Collins Fred C.
Published: May 2019

The allelopathic potential of wheat [Triticum aestivum(L.) ‘Doublecrop′] straw residue was evaluated on weed-seed germination and seedling growth. The inhibition of weed-seed germination and seedling growth was extract-, species-, and temperature-dependent. The extracts prepared by agitating and soaking caused greater inhibition than those obtained by leaching. The descending order of species susceptibility was ivyleaf morningglory [Ipomoea hederacea(L.) Jacq.], velvetleaf (Abutilon theophrastiMedic.), pitted morningglory (Ipomoea lacunosaL.), hemp sesbania [Sesbania exaltata(Raf.) Cory], sicklepod (Cassia obtusifoliaL.), and Japanese barnyard millet [Echinochloa crus-gallivar.frumetaceae(Roxb.) Link]. Incubation at 35 C caused the greatest inhibition of germination and growth.
Influence of Napropamide on the Uptake and Translocation of Mineral Nutrients
Authors: Devlin Robert M. , Zbiec Irena I. , Karczmarczyk Stanislaw J.
Published: May 2019

Napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] is a preemergence herbicide used for the control of most annual grasses and many annual broadleaf weeds. Its influence on the uptake and translocation of N, P, K, Ca, Mg, Cu, Fe, and Zn by four plant species was observed. Napropamide influenced, in some cases dramatically, the uptake and movement of the essential elements, but its influence was not consistent from one type of plant to another.
Evaluation of Precursors and Analogs of Strigol as Witchweed (Striga asiatica) Seed Germination Stimulants
Authors: Pepperman Armand B. , Connick William J. , Vail Sidney L. , Worsham A. Douglas , Pavlista Alexander D. , Moreland Donald E.
Published: May 2019

Thirty compounds that are precursors, analogs, derivatives, or fragments of strigol were prepared and tested for their activity as witchweed [Striga asiatica(L.) Kuntze] seed-germination stimulators. Five compounds showed significant stimulatory activity. Among these were 5-ethoxy-3-methyl-2(5H)-furanone, 3-hydroxy-2,6,6-trimethylcyclohex-1-ene-1-carboxaldehyde, a two-ring analog of strigol, and two isomers of a three-ring analog. Several of the other 25 compounds showed slight and/or non-reproducible activity when dimethylsulfoxide was used as the carrier at 0.1% (v/v) in aqueous solutions. Compounds with such diverse structures as trimethylcyclohexenes, furanones, and bicycloheptenones were among those that possessed some stimulatory activity.
Mobility and Distribution of Buthidazole and Metabolites in Four Leached Soils
Authors: Weber Jerome B. , Peeper Thomas F.
Published: May 2019

Buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl}-4-hydroxyl-1-methyl-2-imidazolidinone} was incubated for 30 days and then leached through Norfolk loamy sand, Lakeland loamy sand, Davidson clay, and Alamance silt loam soils. Similar amounts of the herbicide leached through all of the soils, but distribution in the soils varied greatly.14C-buthidazole distribution in the Lakeland and Norfolk sandy soils was relatively uniform throughout the soil columns. In the Alamance silt loam and Davidson clay, much greater amounts of buthidazole were found in the upper soil zones than in the lower zones. Six metabolites of buthidazole (dihydroxy, desmethyl dihydroxy, dehydrate, methylurea, urea, and amine) were distributed in varying amounts in each of the soils.
Germination of False Broomweed (Ericameria austrotexana) Seed
Authors: Mayeux H. S.
Published: May 2019

Within 1 yr of collection, 60% or more of false broomweed (Ericameria austrotexanaM. C. Johnst.) seed germinated at continuous temperatures from 15 to 30C if light was provided for 8 h daily. Maximum radicle elongation and fresh weight of 14-day-old seedlings occurred at 25 and 30C. Alternating temperatures did not enhance germination, and germination was suppressed in the dark. Germination, time required for germination, and early seedling vigor were tolerant of CaCl2and MgCl2solutions at concentrations as high as 200 mM, but NaCl reduced germination at concentrations in excess of 100 mM. Germination was sensitive to polyethylene glycol solution osmotic potentials of 0.6 mPa or more. Reduced germination in salt solutions was attributed to an osmotic effect rather than a direct effect of ions. Other than an inability to germinate when soil water is limited, no narrow environmental requirements appear to restrict establishment of this undesirable rangeland shrub.
Germination and Emergence of Little Barley (Hordeum pusillum)
Authors: Fischer M. Leon , Stritzke J. F. , Ahring Robert M.
Published: May 2019

Little barley (Hordeum pusillumNutt.) seeds germinated readily without pregermination chilling on substrates moistened with either water or 0.2% aqueous KNO3. Little barley seeds were physiologically mature and viable as early as 11 days after flowering. Pregermination chilling induced dormancy in mature seeds moistened with water, but not those moistened with 0.2% KNO3. Mature seeds frequently germinated better at alternating temperatures from 20C (16 h) to 30C (8 h) than at constant 20C. Germination of seeds after 1 week in a thermogradient table varied from 1% at 34C to 77% at 21C. Seeds were able to germinate over an extended period in the fall and spring. Forage and seed production were highest from the first fall planting date and decreased with later plantings. Plants emerging from seeds planted in March and April did not produce seed.
Fate of Metribuzin, Metolachlor, and Fluometuron in Soil
Authors: Bouchard Dermont C. , Lavy Terry L. , Marx Dave B.
Published: May 2019

Adsorption of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] and fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] on a Taloka silt loam (Mollic Albaqualf) and a Roxana silt loam (Typic Udifluvent) from the 10- to 20- and 40- to 50-cm soil depths was measured. The order of adsorption of the herbicides was fluometuron = metolachlor > metribuzin. Adsorptivity of the soil from the 10- to 20-cm depth was greater than from the 40- to 50-cm depth. At 7, 15, 23, and 37C, all herbicides degraded more rapidly as temperature increased. Metribuzin was least persistent and fluometuron and metolachlor were similarly persistent. The time required for the initial herbicide concentration to decrease by 50% in the Taloka silt loam from the 10- to 20-cm depth at 23C was 2.6, 9.4, and 10.1 weeks for metribuzin, fluometuron, and metolachlor, respectively.
Evaluation ofAlternaria cassiaefor the Biocontrol of Sicklepod (Cassia obtusifolia)
Authors: Walker H. Lynn , Riley Joe A.
Published: May 2019

A method is described to produce inoculum ofAlternaria cassiaeJurair and Khan for biocontrol studies. Approximately 8 g of a conidial preparation containing 1 × 108conidia/g were produced per liter of growth medium. In greenhouse studies the effectiveness ofA. cassiaeas a biocontrol agent for sicklepod (Cassia obtusifoliaL.) was affected by dew-period temperature, dew-period duration, inoculum concentration, and the stage of growth of sicklepod seedlings at the time of inoculation. Optimum environmental conditions included at least 8 h of free moisture at 20 to 30C. Spray mixtures containing approximately 5 × 104or more conidia/ml gave maximum control when sicklepod seedlings were sprayed to runoff. Sicklepod seedlings in the cotyledon to first-leaf stage were most susceptible to the pathogen.
Influence of Nitrogen and Humidity on Rhizome Bud Growth and Glyphosate Translocation in Quackgrass (Agropyron repens)
Authors: McIntyre Gordon I. , Hsiao Andrew I.
Published: May 2019

When buds on the rhizome of quackgrass [Agropyron repens(L.) Beauv.] were released from apical dominance either by increasing the nitrogen supply to the parent shoot (from 5.25 to 210 ppm) or by raising the humidity around the rhizome (from 55 to 100%), the growth response of the buds was closely correlated with their uptake of foliar-applied14C-labeled glyphosate [N-(phosphonomethyl] glycine]. The14C level in the buds, expressed on a dry-weight basis, was greatest in the youngest, most rapidly growing bud at the apical node and decreased in successively older buds along the rhizome. A similar gradient was shown by the14C content of the associated rhizome nodes. The high-humidity treatment also increased the total amount of14C that was translocated into the rhizome, whereas increasing the nitrogen supply, while promoting14C uptake by the buds, markedly reduced the amount in the rhizome nodes and in other parts of the plant. This nitrogen-induced reduction in translocation was associated with a reduction of about 30% in uptake of the herbicide by the treated leaves.
Translocation of Different 2,4-D, Bentazon, Diclofop, or Diclofop-Methyl Combinations in Oat (Avena sativa) and Soybean (Glycine max)
Authors: Hall Chris , Edgington Lloyd V. , Switzer Clayton M.
Published: May 2019

Oat (Avena sativaL. ‘Elgin′) and soybean (Glycine maxL. ‘Evans′) were treated with14C-diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy] propionic acid]} or14C-diclofop alone or in combination with 2,4-D [(2,4-dichlorophenoxy)acetic acid] or bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] and14C-2,4-D alone or in combination with diclofop-methyl or diclofop. More radioactivity was recovered in the treatment zone after14C-diclofop-methyl applications, alone or in combination, than after similar14C-diclofop treatments in oat and soybean. Basipetal movement of radioactivity was 4 and 1% and acropetal movement was 1 and 4% in oat and soybean, respectively, regardless of the diphenyl ether treatment or time. Addition of 2,4-D or bentazon did not reduce translocation of radioactivity from14C-diclofop-methyl treatments in either plant species. Basipetal movement of radioactivity from14C-diclofop-methyl was greater than from14C-diclofop in both oat and soybean. The addition of diclofop-methyl or diclofop did not affect the pattern or amount of14C-2,4-D radioactivity translocated. In oats, radioactivity appeared to accumulate within the intercalary meristematic region with14C-2,4-D and14C-diphenyl-ether applications. Diclofop-methyl at 1 kg/ha applied either to an entire oat plant at the three-leaf stage or the apical meristemic region resulted in plant mortality. The extent to which transport contributes to diclofop-methyl efficacy is questioned.
Computer-Printed Weed-Control Research Reports
Authors: Bowes Garry G. , Hunter James H. , Kaplansky Marvin
Published: May 2019

A computer-based data collection system is described. It captures all the qualitative and quantitative data necessary to print an abstract from a weed-control experiment. The output is in the form of a research report that contains many abstracts. Users of the system are weed workers in western Canada who wish to contribute to the annual edition of the Research Report of the Expert Committee on Weeds (Western Canada). Each year, users fill out a set of forms and send them to a central location where the data are entered into a computer. In 1976, 60% of the research report was successfully computer-printed. The computer system captured a higher percentage of weed-control information than was present in the old system with narrative reports. A survey of weed workers indicated that the type of information entered in the report was satisfactory.
Detection and Degradation of Linuron in Organic Soils
Authors: Mapplebeck L. , Waywell C.
Published: May 2019

Detection and degradation of linuron [3-(3,4-dichlorophenyl) -1 - methoxy -1 - methylurea] in organic soils were studied using biological assays and chromatographic techniques. The level of linuron that caused 50% growth reduction of onion (Allium cepa L.) varied among three soils of greatly differing organic matter contents. Linuron and its metabolites were successfully separated with florisil column chromatography using a five-fraction solvent system; however, only linuron and 3 - (3,4 - dichlorophenyl) -1 -methylurea could be extracted from organic soil samples at satisfactory recovery rates. Soil samples from eight grower fields and from field plots were analyzed to determine the residue level of these two compounds. Quantitative assessment of the compounds was made with high pressure liquid chromatography. Results of the biological assay and chromatographic analysis showed that linuron and its phytotoxic metabolite, 3 - (3,4 - dichlorophenyl) -1 - methylurea, were not accumulating in the organic soils of Ontario and that the levels detected were not phytotoxic to onions when grown in pot bioassays.
Characterization of Atrazine Accumulation by Excised Velvetleaf (Abutilon theophrasti) Roots
Authors: Price Thomas P. , Balke Nelson E.
Published: May 2019

Long-term absorption of14C-atrazine [2-chloro-4 - (ethylamino) - 6 - (isopropylamino) -s- triazine] by excised velvetleaf (Abutilon theophrastiMedic.) roots was investigated. A rapid, initial phase of absorption was followed by a long-term, linear phase of absorption, which resulted in atrazine accumulation in the tissue to concentrations above the external solution. This accumulation did not result from metabolism of the atrazine. Aging of the excised tissue appeared to be responsible for the accumulation. Dinitrophenol, but not cyanide, inhibited accumulation. Atrazine accumulation decreased as the temperature during absorption was decreased. The Q10the absorption rate was ca. 2.5 between 15 and 25 C. Efflux of atrazine from the tissue occurred in two phases. At 25 C, loss of 80% of the atrazine occurred in 20 min. At 4C, the rate of this efflux was slower and the phase lasted longer. At both 4 and 25 C a second, slower phase of efflux occurred through at least 6 h and resulted in loss of equal amounts of atrazine at the two temperatures. These experiments show that, in addition to rapid absorption of atrazine to a passive equilibrium, excised velvetleaf roots accumulate atrazine by a metabolically dependent process over long periods of time.
Ivyleaf Morningglory (Ipomoea hederacea) Control with Herbicides in Soybeans (Glycine max)
Authors: Prosch S. D. , Kapusta George
Published: May 2019

When trifluralin [α,α,α - trifluoro - 2,6 - dinitro -N,N-dipropyl-p-toluidine] was manually incorporated in small field plots to a depth of 10 cm, ivyleaf morningglory [Ipomoea hederacea(L.) Jacq.] was controlled more effectively than when incorporation was only 5 cm deep. No significant differences in ivyleaf morningglory control were observed between different incorporation depths when trifluralin was mechanically incorporated in large field plots. Ivyleaf morningglory emerging from 10 cm deep was controlled to a greater degree than that emerging from 5 cm deep. Preplant incorporated (PPI) trifluralin plus alachlor [2 - chloro – 2′, 6’ - diethyl -N- (methoxymethyl)acetanilide ] applied preemergence (PE) controlled up to 92% of the ivyleaf morningglory compared to 33 and 15% respectively, when these herbicides were applied alone at equal rates. This indicates a synergistic interaction between these two compounds. Trifluralin PPI plus RH 8817 [5-(2-chloro-4-trifluoromethyl phenoxy) - 2 - nitrobenzoic acid ethyl ester] and alachlor applied PE controlled ivyleaf morningglory more effectively (88 to 94%) than all other treatments. Soybean [Glycine max(L.) Merr.] injury and stand reduction were less than 5% in all studies.
AnAlternariasp. on Leafy Spurge (Euphorbia esula)
Authors: Krupinsky Joseph M. , Lorenz Russell J.
Published: May 2019

In 1979 and 1980, isolates ofAlternariawere obtained from diseased leafy spurge (Euphorbia esulaL.) plants. The pathogenicity of anAlternariasp. towards leafy spurge was demonstrated in glasshouse and limited field studies, and theAlternariais considered to be a potential biological - control agent for leafy spurge. The pathogenicity and cultural characteristics of the fungus suggest its classification asA. tenuissimaf. sp.euphorbiae,with isolate Krupinsky 80-3547ss4 (= E. G. Simmons 35-079) as a representative strain.
Tolerance of Alsike Clover (Trifolium hybridum), Red Clover (T. pratense), and Birdsfoot Trefoil (Lotus corniculatus) to TCA and Dalapon
Authors: McGraw Robert L. , Wyse Donald L. , Elling Laddie J.
Published: May 2019

Three field experiments, each for a 2-yr duration, were initiated to evaluate the efficacy of TCA (trichloroacetic acid) and dalapon (2,2 - dichloropropionic acid), alone or in combination, for the selective control of alsike clover (Trifolium hybridum L.) and red clover (T. pratense L.) during the establishment of birdsfoot trefoil (Lotus corniculatus L.). TCA at 6.7 kg/ha gave 95% control of alsike control. TCA at 13.5 kg/ha gave 92% control of red clover and the combination treatment of 6.7 kg/ha of TCA plus 9.0 kg/ha of dalapon gave 95% control of red clover. Birdsfoot trefoil tolerated TCA and dalapon alone or in combination.
Control of Rayless Goldenrod (Isocoma wrightii) with Soil-Applied Herbicides
Authors: Ueckert Darrell N. , Whisenant Steven G. , Sultemeier George W.
Published: May 2019

Picloram (4-amino-3,5,6-trichloropicolinic acid) applied at 0.6 to 1.2 kg/ha as 5 or 10% pellets during the summer or fall usually killed 90% or more of the rayless goldenrod [Isocoma wrightii (Gray) Rydb.] on sandy loam soils in western Texas, whereas the higher rates were necessary for 80% or greater control following winter applications. Acceptable control persisted for 4 yr. Applications of tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea}at 1.1 kg/ha as 20% pellets during summer controlled 85% of the rayless goldenrod, but summer applications of tebuthiuron at 0.6 kg/ha or winter applications at 0.6 or 1.1 kg/ha did not control the weed effectively. Dicamba (3,6-dichloro-o-anisic acid) applied at 0.6 or 1.1 kg/ha as 5% granules did not control rayless goldenrod. Prescribed burning in late February reduced the density of rayless goldenrod 18 to 41%, but decreased control with soil-applied picloram or tebuthiuron. Reduction in rayless goldenrod densities of 75% or greater following applications of picloram or tebuthiuron pellets more than doubled the estimated carrying capacity of the arid rangeland.
An Inexpensive Combustion Apparatus for Preparation of Radioactive Samples
Authors: Bucholtz Dennis L. , Hess F. Dan
Published: May 2019

The combustion apparatus described provides a rapid and inexpensive alternative for measurement of radioisotopes in plant parts. The apparatus utilized a nickel-chromium resistance wire connected to a low-voltage transformer to generate the heat required to ignite the plant tissue. The nickel-chromium wire also served as the sample holder. Combustion was performed in an O2-flushed liquid scintillation vial, and the combustion gases containing either 14CO2 or 3H2O were trapped in situ, scintillant was added, and the vials assayed for radioactivity. The percentage of the radioactivity recovered after combustion was 96.0 for 14C and 93.4 for 3H with standard deviations of 6.8 and 3.0%, respectively.
Electronic Speed Regulator for Operator-Propelled Plot Sprayers
Authors: Baker John B.
Published: May 2019

Construction and use of a portable electronic metronome as an aid in maintaining the desired speed while spraying with an operator-propelled sprayer is described. Use of such a metronome should minimize fluctuations in spray application caused by variations in walking speed during spraying.
An Experimental Incorporator-Planter for Cotton (Gossypium hirsutum)
Authors: Miller John H. , Carter Lyle M. , Carter Charles H.
Published: May 2019

A compact incorporator-planter, which incorporates herbicides into moist soil simultaneously with planting of cotton (Gossypium hirsutumL.), was constructed and evaluated over 3 yr using six herbicides. Weed control was consistent with that reported for large, cumbersome units utilizing standard planters and incorporating units from ground-driven rotary tillers and was enhanced in seasons in which rain fell during the first 3 weeks after planting. Among the dinitroaniline herbicides, dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine) controlled barnyardgrass [Echinochloa crus-galli(L.) Beauv.], and redroot pigweed (Amaranthus retroflexusL.) most effectively. Cotton stands and yields were equivalent to those obtained using standard cotton-planting methods.
Metabolism of Terbacil in Strawberry (Fragaria × ananassa) and Goldenrod (Solidago fistulosa)
Authors: Genez Andree L. , Monaco Thomas J.
Published: May 2019

Terbacil (3-tert-butyl-5-chloro-6-methyluracil) metabolism was evaluated as a possible basis of tolerance in two species, strawberry (Fragaria × ananassaDuchesne) and goldenrod (Solidago fistulosaMiller). Reported cultivar variation in strawberry tolerance to terbacil was examined by comparing herbicide metabolism patterns in an established tolerant cultivar, 'Sunrise’, with those of the reported susceptible cultivar, ‘Guardian’. A terbacil-sensitive plant, cucumber (Cucumis sativusL. ‘Chipper’), was also used as a basis for comparison. Using gradient elution high performance liquid chromatography (HPLC), two terbacil metabolites were separated and quantitated from methanol extracts of the three species treated with14C-terbacil via roots in solution culture. The minor metabolite was identified as the non-phytotoxic derivative, 3-tert-butyl-5-chloro-6-hydroxymethyluracil, based on its co-migration with authentic 3-tert-butyl-5-chloro-6-hydroxymethyluracil in two chromatographic systems. The major metabolite was a glycoside, which yielded the hydroxylated derivative upon β-glucosidase hydrolysis. In all species, metabolites accumulated more rapidly and extensively in roots than in leaves. Metabolism was greater in the two tolerant species than in cucumber. However, the greater tolerance of goldenrod to terbacil compared to that of strawberry was apparently unrelated to differences in herbicide metabolism.
Redweed (Melochia corchorifolia) Germination as Influenced by Scarification, Temperature, and Seeding Depth
Authors: Eastin E. Ford
Published: May 2019

Scarification of freshly harvested redweed (Melochia corchorifoliaL.) seed for 15 to 30 s in an electric scarifier equipped with 100- to 120-grit emery cloth resulted in the best germination. Scarified seed germinated best at 35 and 40C. At 10 and 45C there was no germination even after 7 days. Seven days after planting in silt loam soil there was 80 to 90% emergence of redweed from depths of 1 to 5 cm, whereas no emergence was observed from depths of 0, 8, or 10 cm.
Absorption of 2,4-D, Dicamba, and Glyphosate by Excised Honeyvine Milkweed (Cynanchum Laeve) Leaves
Authors: Soteres John K. , Murray Don S. , Basler Eddie
Published: May 2019

Absorption of 2,4-D [(2,4-dichlorophenoxy) acetic acid], dicamba [3,6-dichloro-o-anisic acid], and the isopropylamine salt of glyphosate [N-(phosphonomethyl) glycine] by excised honeyvine milkweed [Cynanchum laeve(Michx.) Pers.] leaves was determined. Experimental variables included leaf position (terminal vs. basal), a surfactant, 4-isopropenyl-1-methylcyclohexane plus unspecified emulsifiers (SA-77), and leaf collection dates. Absorption of the three herbicides by terminal and basal leaves was increased by the addition of the surfactant. However, the surfactant increased absorption into basal leaves more than into terminal leaves. The surfactant reduced surface tension and increased drying time of water droplets on adaxial leaf surfaces by 50%. The pH of the herbicide solutions was reduced from about 5.8 to about 3.9 by SA-77. Absorption of all three herbicides was greater into terminal than into basal leaves when the surfactant was not present, but the difference disappeared when the surfactant was added. Generally, no differences were observed in the absorption of 2,4-D and dicamba. Glyphosate absorption was greater in terminal leaves collected after a period of adequate moisture than after a period of dry soil conditions.
Fluridone for Annual Weed Control in Western Irrigated Cotton (Gossypium Hirsutum)
Authors: Miller John H. , Carter Charles H.
Published: May 2019

For 3 yr, fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone} at 0.1, 0.2, and 0.3 kg/ha, was applied with or without 0.6 kg/ha of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) before the preplanting irrigation for cotton (Gossypium hirsutumL.). Without trifluralin, fluridone at 0.1 kg/ha controlled less than 60% of annual grasses or redroot pigweed (Amaranthus retroflexusL.), but the 0.3-kg/ha rate controlled 90%. With trifluralin, fluridone at all rates controlled 98% of these weeds. Fluridone alone controlled 85% or more of black nightshade (Solanum nigrumL.). Fluridone did not alter cotton stand or yield. Fluridone residues 8 months after treatment reduced growth of several crops and weeds by 75% or more.
Protection of Grain Sorghum (Sorghum bicolor) from Chloroacetanilide Herbicide Injury
Authors: Roeth Fred W. , Burnside Orvin C. , Wicks Gail A.
Published: May 2019

CGA-43089 [α-(cyanomethoximino)-benzacetonitrile] seed treatment was evaluated at three Nebraska locations during 1979 and 1980 for grain sorghum [Sorghum bicolor(L.) Moench] protection from injury by metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], four other chloroacetanilide herbicides, and three metolachlor +s-triazine combinations. Acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-o-acetotoluidide] caused the most frequent and severest injury to unprotected and protected sorghum. Soilincorporated metolachlor produced more consistent injury than preemergence application to unprotected sorghum, but placement did not affect CGA-43089 protection. Sorghum-stand reduction was the type of injury most frequently encountered, but crop yield was least affected. CGA-43089 always protected the grain sorghum from yield reduction with these herbicides.
Effect of Three Tillage Systems on the Persistence of Atrazine
Authors: Bauman Thomas T. , Ross Merrill A.
Published: May 2019

Field sudies on the persistence of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] showed less persistence under coulter than chisel or conventional plow tillage in the year of application. The residue on the coulter system from the previous corn (Zea maysL.) crop initially prevented as much as 30% of the atrazine from reaching the soil surface. After five annual applications, the atrazine residue was generally higher in the coulter than the chisel or conventional tillage systems, but below levels considered to be biologically active.
IL PLURALISMO POLARIZZATO: CRITICHE E REPLICHE
Authors: Sartori Giovanni
Published: May 2019

Introduzione

La teoria del pluralismo polarizzato mi sovvenne una ven-tina di anni fa. Il saggio al quale ancor oggi i più fanno riferimento — European Political Parties: The Case of Polarized Pluralism — fu pubblicato nel 1966 ma scritto nel 1963, e ci pensai a lungo. Rifacendo mente locale, in quegli anni imperava Duverger, il quale non mi convinceva affatto. Mi convinceva assai di più Almond e soprattutto la sua distinzione, in chiave di cultura politica, tra cultura «omogenea» (e secolarizzata) e cultura «frammentata», che era poi come dire tra consenso e no (nei valori e credenze di fondo). Ma poi Almond approdava alla tripartizione tra sistemi bipartitici, multipartitismo funzionante (Scandinavo e Olandese) e multipartitismo malfunzionante (del grosso dell'Europa continentale), e quell'approdo non quadrava. Intanto, il gruppo dei paesi Scandinavi non era per nulla omogeneo: la Finlandia non era per nulla simile alla Svezia e alla Norvegia. In secondo luogo, se la variabile esplicativa di fondo era la cultura politica, allora l'Olanda (con una subcultura non-secolarizzata, e quindi a cultura frammentata) non doveva risultare funzionante. Alla stessa stregua, anche l'Austria avrebbe dovuto essere malfunzionante. E che dire, poi, della Svizzera? Mi sembrava, dunque, che il discorso mancasse di inquadramento teoretico. Nel saggio iniziale detto inquadramento (o modello) veniva formulato così:

I sistemi di partito verranno analizzati in funzione a) del numero dei poli, b) della loro distanza, c) delle loro interazioni centripete 0 centrifughe … ‘Bipolare’ e ‘multipolare’ indicano quanti sono i perni attorno ai quali ruota il sistema; ‘polarita’ indica una forte distanza tra i poli laterali del sistema (e quindi un basso grade di consenso…); laddove ‘polarizzazione’ e ‘depolarizzazione’ alludono alla dinamica del sistema e denotano rispettivamente un processo centrifugo di dilacerazione del consenso, ovvero un processo centripeto di ricomposizione del consenso… II pluralismo estremo e.; con ogni probabilita centrifugo.
GEOPOLITICA, SICUREZZA EUROPEA E PACE MONDIALE NELL'ERA NUCLEARE
Authors: Zoppo Ciro Elliot
Published: May 2019

Introduzione

All'inizio degli anni ‘80 tutti gli aspetti politici e militari dei rapporti Est-Ovest si presentano sempre piò mutevoli e anche potenzialmente densi di pericoli. Le relazioni strategiche America-Russia hanno subito importanti modifiche negli anni ‘70, diventando meno stabili. I risultati politici di questo mutamento sono esemplificati dal quasi totale arresto del processo di distensione fra Russia e America. Le principali conseguenze sono la preoccupazione dell'Europa Occidentale per le posizioni americane e, dopo l'Afghanistan, per le intenzioni sovietiche. Indubbiamente, ci troviamo nella storia del dopoguerra ad un punto in cui la pace mondiale potrebbe essere messa in pericolo dalla instabilità emergente nei rapporti di deterrenza strategica America-Russia e dal deteriorarsi dell'equilibrio Est-Ovest in fatto di armamenti convenzionali in Europa e altrove. Storicamente, dalla fine della seconda guerra mondiale, l'Europa ha giocato, geograficamente, economicamente, militarmente e politicamente, un ruolo decisivo nel destino dell'umanità e della pace. Con ciò non si vogliono sottovalutare o trascurare il ruolo internazionale che il Giappone, e poi la Cina e l'India, hanno avuto nel ventesimo secolo, e la crescente influenza politica ed economica sulla sicurezza internazionale dei paesi del Terzo Mondo ricchi di materie prime.
LE ORIGINI DEL WELFARE STATE: TEORIE, IPOTESI ED ANALISI EMPIRICA
Authors: Alber Jens
Published: May 2019

Introduzione

Le origini dei contemporaneiwelfare stateeuropei risalgono alla istituzionalizzazione dei primi sistemi di assicurazione sociale alla fine del XIX secolo. Nonostante una così lunga tradizione storica di politica sociale, la teoria macrosociologica ha sorprendentemente trascurato per lungo tempo lo sviluppo delwelfare state. Solo negli ultimi anni la ricerca delle scienze sociali ha cominciato ad occuparsi con maggiore interesse dei fattori che determinano le uniformità e le divergenze nello sviluppo delle politiche sociali, mirando ad offrirne delle spiegazioni teoriche. È vero che anche le teorie piò recenti non si presentano come tentativi di spiegare i «dati di fatto» dello sviluppo delwelfare state; tuttavia, tali teorie constano spesso di asserzioni che sono suscettibili di verifica empirica.
INTERDIPENDENZA E RELAZIONI INTERNAZIONALI: L'ANALISI CONCETTUALE
Authors: Santoro Carlo M.
Published: May 2019

Introduzione

La crescente complessità delle strutture politiche e la rapida evoluzione del sistema internazionale hanno reso di attualità la domanda che la società degli «Stati-nazione» si era già posta invano nel passato: quale morfologia assumerà il sistema delle relazioni internazionali se la moltiplicazione dei flussi di comunicazione e l'incremento quantitativo degli attori non statuali dovesse modificare, fino a sostituire, il modello di funzionamento basato sui soli attori nazionali nelle due varianti storicamente verificate del «sistema dell'equilibrio» e di quello «bipolare»? Si giungerà a quella che Rosenau ha recentemente definito come la «transnazionalizzazione degli affari mondiali», intendendo con il termine «transnazionalizzazione il processo attraverso il quale le relazioni internazionali condotte dai governi sono state integrate dalle relazioni fra individui, gruppi, e società che possono avere ed hanno importanti conseguenze per il corso degli eventi»?
TERRORISMO E GOVERNABILITÀ
Authors: Bonanate Luigi
Published: May 2019

Introduzione

Il terrorismo e l'ingovernabilità si sono imposti all'attenzio-ne degli studiosi come i due più vistosi fattori di crisi dei sistemi politici attuali contemporaneamente, in termini cronologici, e cioè all'inarca alla metà degli anni Settanta, ma indipendentemente, o separatamente l'uno dall'altro dal punto di vista concettuale. Entrambi riguardano lo stato, il primo perché mira a distruggerlo; la seconda perché ne diagnostica una malattia, cioè il «sovraccarico» che lo ha reso incapace di esercitare le sue funzioni di governo. Entrambi inducono, per ragioni diverse, a concludere che i sistemi politici che si trovano a fronteggiarli (l'uno o l'altra) sono in crisi.
Further situating learner possible selves in context: A proposal to replicate Henry and Cliffordson (2013) and Lasagabaster (2016)
Authors: Serafini Ellen J.
Published: May 2019

Research conducted over the past 15–20 years has revealed significant insights into the nature and role of learner selves in language learning settings, particularly the importance of considering the interaction between situated contextual factors and the ways learners perceive, imagine, and construe their possible selves. To further advance this active line of investigation, this article first reviews key previous research and argues for the need to address the generalizability of learner possible selves through replication of original research conducted with different types of learners in diverse social and educational contexts, particularly in multilingual settings and in relation to learning target languages (TLs) other than English. Then, two studies are identified as ideal for replication, and their motivation, methods, and findings are reported in detail. To strengthen the validity and reliability of the original studies’ findings, several suggestions are made for ways to replicate the focal studies as a necessary first step in building robust comparative evidence. As an important second step in this endeavor, the article concludes by arguing for the value of case studies that align with current dynamic conceptualizations of the self.
Equational properties of fixed-point operations in cartesian categories: An overview
Authors: Ésik Z
Published: May 2019

Several fixed-point models share the equational properties of iteration theories, or iteration categories, which are cartesian categories equipped with a fixed point or dagger operation subject to certain axioms. After discussing some of the basic models, we provide equational bases for iteration categories and offer an analysis of the axioms. Although iteration categories have no finite base for their identities, there exist finitely based implicational theories that capture their equational theory. We exhibit several such systems. Then we enrich iteration categories with an additive structure and exhibit interesting cases where the interaction between the iteration category structure and the additive structure can be captured by a finite number of identities. This includes the iteration category of monotonic or continuous functions over complete lattices equipped with the least fixed-point operation and the binary supremum operation as addition, the categories of simulation, bisimulation, or language equivalence classes of processes, context-free languages, and others. Finally, we exhibit a finite equational system involving residuals, which is sound and complete for monotonic or continuous functions over complete lattices in the sense that it proves all of their identities involving the operations and constants of cartesian categories, the least fixed-point operation and binary supremum, but not involving residuals.
Some Ethical Problems in Special Education
Authors: Codd John A.
Published: May 2019

This paper examines, from a philosophical perspective, some of the main ethical problems pertaining to the special education field. It is argued that while special education practice has been strongly grounded in psychological theory, it has not always been adequately justified by reference to general moral principles. Rationales for intervention are mostly couched in descriptive or explanatory terms while the over-riding prescriptive or evaluative dimensions are often presupposed without explicit justification. Particular issues such as diagnostic assessment, educational placement and behavioural management can be seen to entail complex ethical problems concerning the consideration of individual rights and interests, equality of educational opportunity, and respect for personal autonomy. Examples of the moral dilemmas inherent in particular special educational practices are examined. Finally, it is claimed that special educators must be able to defend not only the empirical bases of their educational theories, but also the value judgments implicit in them.
Temporal trends in food group availability and cancer incidence in Africa: an ecological analysis
Authors: Aglago Elom K , Bray Freddie , Zotor Francis , Slimani Nadia , Chajès Veronique , Huybrechts Inge , Ferrari Pietro , Gunter Marc J ,   the Members of the African Cancer Registry Network
Published: May 2019

Objective:

We evaluated the relationship between food availability, as the only dietary exposure data available across Africa, and age-standardised cancer incidence rates (ASR) in eighteen countries.

Design:

Ecological study.

Setting:

Availability of food groups and dietary energy was considered for five hypothetical time points: years of collection of ASR (T0) and 5, 10, 15 and 20 preceding years (T–5,T–10,T–15,T–20). Ecological correlations adjusted for human development index, smoking and obesity rates were calculated to evaluate the relationship between food availability and ASR of breast, prostate, colorectal, oesophageal, pancreatic, stomach and thyroid cancer.

Results:

Red meat was positively correlated with pancreatic cancer in men (T–20:r–20= 0·61,P< 0·05), stomach cancer in women (T0:r0= 0·58,P< 0·05), and colorectal cancer in men (T0:r0= 0·53,P< 0·05) and women (T–20:r–20= 0·58,P< 0·05). Animal products including meat, animal fats and higher animal-sourced energy supply tended to be positively correlated with breast, colorectal, pancreatic, stomach and thyroid cancer. Alcoholic beverages were positively correlated to oesophageal cancer in men (r0= 0·69,P< 0·001) and women (r–20= 0·72,P< 0·001).

Conclusions:

The present analysis provides initial insights into the impact of alcoholic beverages, and increasing use of animal over plant products, on the incidence of specific cancers in Africa. The findings support the need for epidemiological studies to investigate the role of diet in cancer development in Africa.
Using data extracted from a radiotherapy record & verify system to infer outcomes of patients treated for radical brain cancer
Authors: Sykes Martin
Published: May 2019

Aim:

The aims of this study were to explore the outcome measures that can be recorded in a radiotherapy IT system and the extract mortality results for a group of patients receiving radical radiotherapy treatment for primary brain cancer.

Method:

Treatment mortality outcomes were extracted from a radiotherapy database and were compared to treatment technique used between 1 January 2011 and 31 December 2017. The patients selected received 1 course of radiotherapy of 60 Gray in 30 treatments (n = 270). These patients received either Conformal Radiotherapy (CRT) (n = 127) or Volumetric Modulated Arc Therapy (VMAT) (n = 143). Kaplan–Meier plots were generated for these two groups to assess the survival. The median survival was 20·1 months (95%CI = 16·8−23·4) and 14·0 months (95%CI = 11·1−16·5) for CRT and VMAT, respectively.

Discussion:

Surprisingly, the results of this data extraction demonstrated that CRT gave better survival for this group of patients, than VMAT. The reason for the difference in survival is unclear and more data are needed to explain the result.

Conclusion:

This demonstrates that not only that a radiotherapy database can be used to extract outcome measures but that it must be done to explore where a change in treatment delivery has been of benefit to the patients or not.
IRREGULAR HODGE FILTRATION OF SOME CONFLUENT HYPERGEOMETRIC SYSTEMS
Authors: Domínguez Alberto Castaño , Sevenheck Christian
Published: May 2019

We determine the irregular Hodge filtration, as introduced by Sabbah, for the purely irregular hypergeometric${\mathcal{D}}$-modules. We obtain, in particular, a formula for the irregular Hodge numbers of these systems. We use the reduction of hypergeometric systems from GKZ-systems as well as comparison results to Gauss–Manin systems of Laurent polynomials via Fourier–Laplace and Radon transformations.
Selective and effective control of field dodder (Cuscuta campestris) in chickpea with granular pendimethalin
Authors: Goldwasser Yaakov , Rabinovitz Onn , Hayut Elad , Kuzikaro Hadar , Sibony Moshe , Rubin Baruch
Published: May 2019

Field dodder is an obligatory stem and leaf plant parasite that causes significant damage in field and vegetable crops in all agricultural regions of the globe. Selective and effective measures to control the parasite are extremely limited. In recent studies, we have shown that granular formulations of dinitroaniline cell division–inhibiting herbicides applied after crop establishment and before dodder germination fit our dodder control strategy and kill the parasite effectively and selectively. The aim of our study conducted from 2014 to 2018 was to evaluate the efficacy and selectivity of granular pendimethalin for dodder control in chickpea under laboratory, greenhouse, and field conditions. Petri dish experiments revealed that the herbicide reduces dodder seed germination while its main effect is a restriction of shoot elongation. Greenhouse experiments demonstrated that the inhibition and distortion of dodder shoot growth impede shoot twining and prevent attachment to the host plant. In dose–response experiments conducted in the greenhouse, we observed that half the recommended rate of granular pendimethalin provides efficient dodder control with no damage to chickpea seedlings. In 3 yr of chickpea field trials, GPM applied across the seeding bed at the recommended rate resulted in high crop yields that were not significantly different from those observed for the untreated no-dodder control, while half of the recommended dose efficiently controlled dodder and other weeds with no damage to the crop, resulting in significantly increased chickpea yields and profitability. These studies indicate that GPM can provide efficient and selective dodder control in chickpea.
Instant White Rice with Pigmented Giant Embryonic Rice Improves Glucose Metabolism and Inhibits Oxidative Stress in High-Fat Diet-Fed Mice
Authors: Chung Soo Im , Rico Catherine W. , Lee Sang Chul , Kang Mi Young
Published: May 2019

Abstract. The effects of instant cooked rice made from a combination of white rice and pigmented giant embryonic Keunnunjami rice, in comparison with those of instant regular white or brown rice and instant non-pigmented giant embryonic brown rice, on the glucose metabolism and antioxidant defense status in high-fat diet-fed mice were investigated. 56 male C57BL/6N mice were randomly divided into 7 dietary groups: normal control, high fat (23 %, HF), and HF supplemented with normal white (HF + NW) or brown rice (HF + NB), non-pigmented giant embryonic rice (HF + GB), and white rice with 8 % Keunnunjami (HF + KJ8) and 18 % Keunnunjami (HF + KJ18). After 7 weeks, HF mice showed marked increases in blood glucose (156 mg/dL), plasma insulin (12.1 mg/mL), and lipid peroxidation, and a significant decrease in hepatic glycogen (14.2 mg/g) relative to the control group (p < 0.05). However, addition of instant NB, GB, KJ8, andKJ18) rice suppressed this high-fat diet-induced hyperglycemia and oxidative stress through altering glucose-regulating enzymes (glucokinase, glucose-6-phosphatase, and phosphoenolpyruvate carboxykinase) and activation of antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase, glutathione reductase, and paraoxonase). Compared with HF mice, HF + KJ8 and HF + KJ18 groups exhibited significantly lower glucose (139–141 mg/dL), insulin (10.6–10.9 mg/mL), and lipid peroxidation and higher glycogen (15.3–16.4 mg/g) (p < 0.05). The hypoglycemic and antioxidant effects of instant KJ8 and KJ18 rice were generally comparable to those of instant NB and GB rice. These findings illustrate that instant rice made from white rice with 8 % Keunnunjami rice may be useful as a functional food with therapeutic potential against hyperglycemia and oxidative damage.
Effects of Ducting on Whistler Mode Chorus or Exohiss in the Outer Radiation Belt
Authors: Hanzelka Miroslav , Santolík Ondřej
Published: May 2019

Previously published statistics based on Cluster spacecraft measurements surprisingly show that in the outer radiation belt, lower band whistler mode waves predominantly propagate unattenuated parallel to the magnetic field lines up to midlatitudes, where ray tracing simulations indicated highly attenuated waves with oblique wave vectors. We explain this behavior by considering a large fraction of ducted waves. We argue that these ducts can be weak and thin enough to be difficult to detect by spacecraft instrumentation while being strong enough to guide whistler mode waves in a cold plasma ray tracing simulation. After adding a tenuous hot electron population, we obtain a strong effect of Landau damping on unducted waves, while the ducted waves experience less damping or even growth. Consequently, the weighted average of amplitudes and wave normal angles of a mixture of ducted and unducted waves provides us with strong quasi‐parallel waves, consistent with the observations.