bluuebunny/crossref_metadata_2025 huggingface dataset:
Interference among Bean (Phaseolus vulgaris), Barnyardgrass (Echinochloa crus-galli), and Black Nightshade (Solanum nigrum)
Authors: Fennimore Steven A. , Mitich L. W. , Radosevich Steven R.
Published: May 2019

The interference between dry bean (Phaseolus vulgarisL. var. Red Kidney), black nightshade (Solanum nigrum♯3SOLNI), and barnyardgrass (Echinochloa crus-galli♯ ECHCR) was examined in replacement series experiments. A modified replacement series experiment also was performed to examine the effects of no interference, and intraspecific and interspecific interference on the height, leaf area, and dry weight of bean, black nightshade, and barnyardgrass. In both types of competition experiments, bean germinated earlier than either weed species and caused significant reductions in weed height, leaf area, and dry weight. The impact of bean upon itself was always greater than the effect of either weed species. In laboratory studies, barnyardgrass and black nightshade seeds were subjected to eight concentrations of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine). Black nightshade was 100 times more tolerant to trifluralin than barnyardgrass. Field studies, conducted at several locations in the Central Valley of California in which trifluralin-treated plots were compared with nontreated plots, demonstrated that trifluralin favors trifluralin-tolerant weeds (black nightshade), but trifluralin-sensitive weeds (barnyardgrass) have not been eliminated despite 20 yr of trifluralin use.
Effects of Trifluralin on Root Morphology and Mineral Status of Wheat (Triticum aestivum) Seedlings
Authors: Olson Barry M. , McKercher Robert B. , Halstead Edward H.
Published: May 2019

Growth chamber studies using one soil investigated the effects of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 0.0, 0.4, and 0.8 ppmw on the root development and the mineral status of wheat (Triticum aestivumL. ‘Neepawa’) seedlings. The 0.8-ppmw trifluralin rate increased the number of seminal roots, reduced lateral root production, decreased root extension, caused root tips to swell (club-like appearance), and reduced root dry weights. However, 0.4-ppmw trifluralin caused only slight damage to the seedlings. Towards the end of the two-week growth period, damaged seedlings showed signs of recovery, which included an increased number of seminal roots, development of normal root extensions from clubbed root tips, and development of normal lateral root patterns. Trifluralin increased percent calcium and magnesium and decreased percent nitrogen, phosphorus, and potassium in wheat plants. The nutrient concentrations were more affected in 21-day-old plants than in 35-day-old plants, indicating the wheat seedlings were able to recover from trifluralin injury.
Control of Cowpea (Vigna unguiculata) in Soybean (Glycine max) with Acifluorfen
Authors: Murphy Tim R. , Gossett Billy J.
Published: May 2019

Acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} applied 7 days after cowpea [Vigna unguiculata(L.) Walp.] emergence (unifoliolate leaf stage) gave better control than later applications. Cowpea control was obtained with one acifluorfen application at 7 days after cowpea emergence in 1981, but in 1980 and 1982, applications at 7 and 14 days were necessary for acceptable control (> 80%). Acifluorfen reduced cowpea plant dry weights relative to the weedy control. A single application 7 days after emergence reduced cowpea plant growth more than one at 21 days after emergence. Of all times of application, the greatest soybean [Glycine max(L.) Merr.] injury occurred when acifluorfen was applied at 7, 14, and 21 days after emergence, but seed yields were not reduced relative to the untreated weed-free control. There was no difference in response among three weedy cowpea cultivars to acifluorfen.
Response of Potato (Solarium tuberosum) Cultivars to Metribuzin
Authors: Friesen George H. , Wall David A.
Published: May 2019

The response of 22 potato (Solanum tuberosumL.) cultivars to soil-incorporated and foliar applications of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)one] at rates of 0.5 and 1.0 kg ai/ha, was evaluated in field experiments from 1979 to 1982. Metribuzin significantly reduced the yield of marketable tubers in several potato cultivars. Foliar applications generally resulted in more injury than soil applications. Yields were reduced primarily through stand reduction and a decreased number of tubers per plant. Neither tuber size nor specific gravity of tubers was significantly reduced in the cultivars studied. The most susceptible cultivar was ‘Alaska Red’, followed by ‘Rhine Red’, F72117, ‘Caribe’, and ‘Shepody’. Other cultivars evaluated were highly tolerant to metribuzin, irrespective of rate or method of application. There was an increase in hollow heart in cultivars ‘Atlantic’ and ‘Lemhi Russet’ following treatment with metribuzin.
Effect of Herbicides on Germination and Growth of Four Grass Weeds
Authors: Young Frank L. , Gealy David R. , Morrow Larry A.
Published: May 2019

In the greenhouse, glyphosate [N-(phosphonomethyl)glycine] at 0.6 kg ae/ha applied directly to seeds alone or seeds on the soil surface reduced germination and shoot dry weight of common rye (Secale cerealeL. ♯3SECCE). Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) applied similarly at 0.6 kg ai/ha reduced germination and shoot dry weight of downy brome (Bromus tectorumL. ♯ BROTE) and wheat (Triticum aestivumL. ‘Daws' ♯ TRZAX). Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H)-one] at 0.6 kg ai/ha applied to seeds, soil, or seeds and soil had very little effect on germination, but significantly reduced shoot dry weight of common rye, downy brome, wheat, and jointed goatgrass (Aegilops cylindricaHost. ♯ AEGCY). Pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide] at 0.6 kg ai/ha, and propham (isopropyl carbanilate) at 3.4 kg ai/ha plus extender (p-chlorophenyl-N-methylcarbamate) at 0.4 kg ai/ha substantially reduced shoot height and dry weight of all species, regardless of application method, with pronamide completely inhibiting shoot elongation and dry-weight production in three of the four species.
Wild Oat (Avena fatua) Seed Environment and Germination
Authors: Somody Carol N. , Nalewaja John D. , Miller Stephen D.
Published: May 2019

Experiments were conducted in the field and laboratory from 1978 to 1981 to determine the effect of crop residues, manure, and inorganic nitrogen on wild oat (Avena fatua L. ♯3 AVEFA) seed (seed as used here represents an intact floret) dormancy. Turkey manure usually stimulated wild oat seed germination more than crop residue, cow manure, or inorganic nitrogen. Seed germination of different wild oat accessions varied in response to turkey manure. Germination of dormant seed in water was stimulated after 8 weeks or after overwintering in the presence of turkey manure in the field and after 10 days in the presence of turkey manure in petri dishes in the laboratory. Turkey manure caused growth of wild oat shoots in petri dishes, but usually roots were absent. A nonmicrobial, water-soluble component of turkey manure was responsible for stimulating wild oat seed germination. Turkey manure treatment of dormant wild oat seed increased the percentage of seed that would not germinate in gibberellic acid. Germination of nondormant wild oat seed of Accession 77 was reduced, but Accession 64 was unaffected by turkey manure. Germination of wild oat was low when the seeds overwintered on the soil surface, regardless of seed age or length of overwintering.
Effects of Weed Density and Defoliated or Undefoliated Soybeans (Glycine max) on Velvetleaf (Abutilon theophrasti) Development
Authors: Higgins Randall A. , Staniforth David W. , Pedigo Larry P.
Published: May 2019

Velvetleaf (Abutilon theophrastiMedic. ♯3ABUTH) grown under monoculture consistently exceeded velvetleaf intercropped with soybeans [Glycine max(L.) Merr. var. ‘Amsoy 71′] in leaf area, nodes with fully developed leaves, canopy width, branches, and number of capsules as early as 3, 3, 4, 5, and 8 weeks, respectively, after simultaneous emergence. Velvetleaf plants without soybean competition eventually developed over nine times the dry matter of velvetleaf intercropped with soybean. The only components of velvetleaf plants sampled which sometimes increased significantly when soybean was defoliated in a manner simulating damage caused by the green cloverworm (GCW) (Plathypena scabraF.) were leaf area, number of leaves, and number of main-stem nodes. Soybeans in Iowa are attacked by the GCW late enough in the growing season that velvetleaf surviving previous weed management efforts benefited only slightly.
Effect of Depth and Duration of Seed Burial on Kochia (Kochia scoparia)
Authors: Zorner Paul S. , Zimdahl Robert L. , Schweizer Edward E.
Published: May 2019

Dormant and nondormant kochia [Kochia scoparia(L.) Schrad. ♯3KCHSC] seed populations were buried at six soil depths in Colorado. Portions of both populations remained viable for 36 months. Persistence increased with burial depth in both populations. Seed loss from the initially dormant population was limited to germination in situ, but seed loss from the initially nondormant population included significant viability loss at burial depths of 10 cm or less. Persistence of both populations was regulated by dormancy retention. Shallow tillage practices are predicted to decrease seed persistence in soil and increase successful seedling emergence. Deep tillage practices are predicted to reduce seedling emergence but increase soil seed populations.
Detection of False Broomweed (Ericameria austrotexana) by Aerial Photography
Authors: Everitt James H. , Ingle Sammy J. , Gausman Harold W. , Mayeux Herman S.
Published: May 2019

False broomweed (Ericameria austrotexanaM.C. Johnst.) had lower near-infrared (0.75- to 0.90-μm waveband) reflectance than did six other associated rangeland species and mixed herbaceous vegetation. False broomweed's low near-infrared reflectance was attributed to its erectophile (erect-leaf) canopy structure. Other species had planophile (horizontal-leaf) or intermediate-leaf orientation. False broomweed's low near-infrared reflectance caused its image to be dark reddish-brown on color-infrared (0.50- to 0.90-μm waveband) film, compared with red or magenta images of other rangeland species. Microdensitometric measurements made on the film showed that false broomweed had significantly higher optical counts than those of associated species and mixtures of species.
Effects of Soil Moisture on the Vegetative Growth of Wild Oat (Avena fatua)
Authors: Akey William C. , Morrison Ian N.
Published: May 2019

The growth of wild oat (Avena fatua L. ♯3 AVEFA) under different moisture regimes was investigated under field conditions and in a growth chamber. In the field, growth of wild oat under low moisture conditions (0.6 cm water per week – Regime 1) was significantly reduced compared to growth under high moisture conditions (2.5 cm water per week – Regime 2). Maximum reductions of 49, 33, and 38% were recorded in the leaf area, dry weight, and number of viable tillers, respectively. The growth of wild oat in soil watered daily to a soil moisture content (SMC) of 10% (water potential −6.5 bars) in the growth chamber was less than for plants in soil watered daily to 20% SMC (-0.3 bars). Maximum reductions of 55, 57, and 38% were recorded in the leaf area, dry weight, and number of viable tillers, respectively. Wild oat growth was more adversely affected by reducing the SMC from 20 to 10% after, rather than before, the four-leaf stage. By the last sampling date, stomatal diffusion resistance of the most severely water-stressed plants was 25 s·cm-1 compared to between 5 and 10 s·cm-1 for the plants receiving more water.
Germination Ecology of Milkweedvine (Morrenia odorata)
Authors: Singh Megh , Achhireddy Nagi Reddy
Published: May 2019

The germination of milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed at 20 or 25 C was unaffected by a 12-h photoperiod. The 12-h photoperiod, however, decreased germination by 50% at 15 C. No germination occurred at 35 C regardless of photoperiod. By alternating 35 C for 12 h with 20 C for 12 h, the germination percentage was 57%. Seedling growth was maximum at alternating temperatures of 30/20 C. Optimum pH for germination and seedling growth was 7 and germination did not occur at pH levels below 6. Seed germination declined steadily at osmotic stress below −0.12 MPa; no germination occurred at −0.5 MPa. Seedling growth was not influenced by osmotic stress down to −0.18 MPa. Germination percentages of seeds kept under aerated water and nonaerated water were similar, but the seedling growth was greater in aerated water. Seedling emergence was maximum from depths of 0.5 to 2.5 cm, but no seedling emerged from 0 or 10 cm. Planting depth was negatively correlated (r = −0.7) with shoot growth but positively correlated (r = +0.98) to root growth.
Control of Annual Morningglories (Ipomoeaspp.) in Soybeans (Glycine max)
Authors: Barker Michele A. , Thompson Lafayette , Godley F. Michael
Published: May 2019

Field studies were conducted in North Carolina in 1981 and 1982 to evaluate the efficacy of postemergence over-the-top and postemergence-directed herbicides for control of five morningglory species: entireleaf [Ipomoea hederacea(L.) Jacq. var.integriusculaGray], tall [Ipomoea purpurea(L.) Roth. ♯3PHBPU], ivyleaf [Ipomoea hederacea(L.) Jacq. var.hederacea♯IPOHE], pitted [Ipomoea lacunosa(L.) ♯ IPOLA], and scarlet [Ipomoea coccinea(L.) ♯IPOCC]. The glabrous morningglories (scarlet and pitted) were more easily controlled than the pubescent morningglories (ivyleaf, tall, and entireleaf). Lower soybean injury, higher morningglory control, and greater soybean seed yields were obtained with over-the-top herbicide applications at 4 weeks after planting (WAP) than at 6 WAP. Pitted morningglory was tolerant to low rates of 2,4-DB [4-(2,4-dichlorophenoxy) butyric acid]. This herbicide applied over the top at the R1 stage of soybean growth produced low yields, probably as a result of morningglory interference and herbicide injury to the soybeans. Postemergence-directed applications of linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] and metribuzin [4-amino-6-tert-butyl-3-(methylthio-as-triazin-5(4H)-one] alone or in tank mixtures with 2,4-DB resulted in soybean injury that ranged from 12 to 36%. Highest soybean seed yields (equivalent to weed-free control) from postemergence-directed herbicides were obtained with applications of 2,4-DB, linuron, and a tank mixture of metribuzin and 2,4-DB.
Effects of Metribuzin Placement on the Foliage of Tomato (Lycopersicon esculentum) and Jimsonweed (Datura stramonium)
Authors: Frank J. Ray , Beste C. Edward
Published: May 2019

Fifty-day-old jimsonweeds (Datura stramoniumL.) were susceptible and tomatoes (Lycopersicon esculentumMill.) tolerant to soil-applied metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] at 0.25 and 0.50 kg/ha. Spray applications of 0.50 kg/ha metribuzin to jimsonweed foliage, or to both foliage and soil, reduced jimsonweed height growth 39 and 66%, respectively; whereas, tomato height was reduced 57 and 50% by the two placement methods, respectively. Metribuzin applied to a basal leaf appeared to move both basipetally and acropetally in jimsonweed, but only basipetally in tomato. Metribuzin applied to tomato leaves reduced growth 28% more when leaves had been abraded than when not abraded. Differential translocation appeared to be a major factor in selectivity. Directed sprays of metribuzin at 0.3 and 0.6 kg/ha on the lower 75% of jimsonweed leaves provided control in the field without injury to tomatoes.
Sunflower (Helianthus annuus) Response to Diclofop
Authors: Gillespie Greg R. , Miller Stephen D.
Published: May 2019

Experiments were conducted in the field, greenhouse, and controlled environmental chambers to determine the injury to sunflower (Helianthus annuusL.) from diclofop (2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid} as influenced by diclofop rate, sunflower line and growth stage, and temperature/relative humidity (RH). Eighteen sunflower lines varied widely in response to diclofop applied postemergence at 2.2 kg/ha with visual injury ratings ranging from 5 to 46%. Neither diclofop-tolerant (Hybrids 894 and 903) nor diclofop-susceptible (Hybrid 923 and Inbred HA290) sunflower lines were injured by diclofop at 10 C. Diclofop injured all four sunflower lines at 30 C. Sunflower injury following diclofop application at 30 C was greater at 90% RH than at 40% RH; and the diclofop-susceptible lines were injured more than the diclofop-tolerant lines. Diclofop injury to sunflower at the two- to four-leaf stage was greater than at any other growth stage in the field and greenhouse. Seed yields of sunflower (Hybrid 894) treated with diclofop in the two- and four-leaf stage was reduced 15 and 12% compared to that of untreated weed-free sunflower, respectively, averaged over diclofop rates.
Cultural Control of Common Waterplantain (Alisma triviale) in Wild Rice (Zizania palustris)
Authors: Ransom Joel K. , Oelke Ervin A.
Published: May 2019

Experiments were conducted to determine the influence of water depth, fall flooding, and burial depth on the development of common waterplantain (Alisma trivialePursh. # ALSPA) in wild rice (Zizania palustrisL.). The optimum water depths for common waterplantain from corms were 20 cm when grown outside in submerged pots at St. Paul and 2 and 15 cm when grown in a sloping field at Grand Rapids. Growth of common waterplantain from seeds was maximum at the lowest water depths (2 to 7 cm) at both locations. Wild rice dry weight and seed yield in the same experiments were maximum at the 20- and 30-cm water depths at St. Paul and the 15- and 28-cm depths at Grand Rapids. The increased wild rice seed yield and dry weight at these depths was related to increased tiller production. Wild rice yield was similar at all water depths at Grand Rapids when grown with common waterplantain from corms at a density of 11 plants/m2. Water depths that decreased the effect of common waterplantain interference with wild rice, reduced wild rice yield. Establishment of common waterplantain from corms was maximum at the 5- and 15-cm depths and was severely reduced at the 0- and 30-cm soil depths in soils not flooded in the fall but flooded in the spring. Fall flooding killed all corms regardless of burial depth. Corm mortality under fall-flooded conditions may be due to the effects of ice-encasement.
Effect of Corn (Zea mays) Seeding Date on the Growth of Yellow Nutsedge (Cyperus esculentus)
Authors: Ghafar Zain , Watson Alan K.
Published: May 2019

Major differences in above- ground biomass and tuber production of yellow nutsedge (Cyperus esculentusL. # CYPES) were not observed when corn (Zea maysL. “CO-OP S265”) was seeded on different dates (1st, 2nd, 3rd and 4th week of May; and 1st week of June). The final seedbed was prepared just prior to each seeding date and this cultivation stimulated dormant tubers to sprout. As a result, a large population of yellow nutsedge emerged with the corn at all seeding dates. Because fertilizer was banded near the corn row, yellow nutsedge biomass, tuber dry weight and number of tubers were higher within corn rows than between rows. Tuber size was affected by seeding date and shifted toward smaller tubers within corn rows and larger tubers between the rows as the corn was sown late. The optimum seeding date of corn was in the 3rd week of May when the highest corn yield was obtained and yellow nutsedge growth was generally reduced.
Effects of Difenzoquat on Photoreactions and Respiration in Wheat (Triticum aestivum) and Wild Oat (Avena fatua)
Authors: Halling Blaik P. , Behrens Richard
Published: May 2019

Experiments were conducted with isolated protoplasts of wild oat (Avena fatuaL. # AVEFA) and isolated chloroplasts of wild oat and wheat (Triticum aestivumL.), to determine if the methyl sulfate salt of difenzoquat (1,2-dimethyl-3,5-diphenyl-1H-pyrazolium) might influence photoreactions in these species. Difenzoquat did not affect CO2fixation, uncoupled electron transport, or proton uptake. At concentrations of 0.5 mM and 1 mM, difenzoquat caused a slight, but statistically significant, inhibition of photophosphorylation. Experiments assaying coupled electron transport indicated that inhibition of photophosphorylation occurred not through uncoupling, but by an energy-transfer inhibition. This same effect was observed in isolated mitocondria of both species, with about 50% inhibition of state 3 respiration rates occurring with 10 μM difenzoquat. However, no important differentials were observed in the relative susceptibilities of wheat and wild oat mitochondria. Difenzoquat also functioned as a weak autooxidizing electron acceptor in photosynthetic electron transport. Therefore, difenzoquat-induced leaf chlorosis and necrosis may result from a bipyridilium-type electron acceptor activity if sufficient herbicide is absorbed.
Antidotes Reduce Injury to Grain Sorghum (Sorghum bicolor) from Acetanilide Herbicides
Authors: Devlin Daniel L. , Moshier Loren J. , Russ Oliver G. , Stahlman Philip W.
Published: May 2019

CGA-43089 [α-(cyanomethoximino)-benzacetonitrile], CGA-92194 {α-[(1,3-dioxolan-2-yl-methyl)imino] benzeneacetonitrile}, and MON-4606 [5-thiazolecarboxylic acid, benzyl ester, 2-chloro-4-(trifluoromethyl)], applied as seed treatments at 1.25 g/kg seed, prevented yield losses in grain sorghum [Sorghum bicolor(L.) Moench.] in the field due to metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], alachlor [2-chloro-2′, 6′-diethyl-N-(methoxymethyl)acetanilide] or acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-o-acetotoluidide] applied at 1.7, 2.2 and 1.7 kg/ha, respectively. CGA-92194, applied at 0.8 g/kg seed, prevented yield reduction from metolachlor applied at 4.5 kg/ha. MON-4606 was more effective in protecting grain sorghum when applied as a seed treatment than when applied in the furrow with a clay or sand granule as carrier.
Ozone-Herbicide Interactions on Sorghum (Sorghum bicolor) and Velvetleaf (Abutilon theophrasti) Seedlings
Authors: Hatzios Kriton K. , Yang Yaw-Shing
Published: May 2019

The potential interactive effects between the herbicides chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl] benzenesulfonamide}, PP009 {butyl 2-[4-[5-(trifluoromethyl-2-pyridinyl) oxy] phenoxy] propanoate}, and BAS 9052 OH {2-[1-(ethoxyimino)-butyl]-5-[2-(ethylthio)-propyl]-3-hydroxy-2-cyclohexene-one} and the air pollutant ozone (O3) on the growth of sorghum [Sorghum bicolor(L.) Moench. ‘Funk G623rg’] and velvetleaf (Abutilon theophrastiMedic. # ABUTH) were examined. All three herbicides were applied postemergence either before or after a single 6-h fumigation of sorghum and velvetleaf seedlings with O3at 0, 0.1, and 0.2 ppmv. Chlorsulfuron was applied at 0, 0.06, or 0.12 kg ai/ha, while PP009 and BAS 9052 OH were applied at 0, 0.6, and 1.2 kg ai/ha. Two weeks after treatment, dry weight responses of velvetleaf seedlings revealed that PP009 interacted synergistically while chlorsulfuron and BAS 9052 OH interacted antagonistically with O3. The sequence of O3fumigation and herbicide treatment appeared to be an important factor determining the type of interactive effects of these herbicides with O3. The interactive effects of all three herbicides with O3on sorghum seedlings were additive regardless of the sequence of O3fumigation and herbicide treatment.
Response of Wheat (Triticum aestivum) and Rotation Crops to Chlorsulfuron
Authors: Brewster Bill D. , Appleby Arnold P.
Published: May 2019

Chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} at rates of 140 g ai/ha and lower did not reduce wheat (Triticum aestivumL. 'Stephens’) grain yield, but soil residues from 35 g/ha injured snap beans (Phaseolus vulgarisL.), alfalfa (Medicago sativaL. ‘DuPuits’), sweet corn (Zea maysL. ‘Jubilee’), Italian ryegrass (Lolium multiflorumLam.), sugarbeets (Beta vulgarisL. ‘Giant Western’), and rape (Brassica napusL. ‘Dwarf Essex’). Chlorsulfuron at 35 g/ha reduced foliage weight of sugarbeets seeded 26 months after application. Phytotoxic levels of the herbicide were present 10 to 20 cm deep, 168 days after application to a silt loam soil. Chlorsulfuron reduced alfalfa petiole length and fresh weight in the greenhouse when mixed in soil at rates as low as 0.025 ppb (w/w).
A Nursery Study of Leafy Spurge (Euphorbiaspp.) Complex from North America
Authors: Ebke Duane H. , McCarty Melvin K.
Published: May 2019

Live root material of leafy spurge (Euphorbiaspp.) was collected from 38 locations across northern United States, southern Canada, and from 1 location in Austria. These materials were established in a nursery at Lincoln, Nebraska along withE. agrariaM. Bieb. andE. cyparissiasL. # EPHCY. Nineteen vegetative and reproductive characters, taken from various taxonomic keys, were measured on plants established for a period of 3 yr. Data were compared with previous taxonomic keys ofEuphorbiaspecies. A key developed by A. Radcliffe-Smith was used to separate the nursery entries. Leaf width measurements were the most useful taxonomic criteria. Five morphologically separable taxa were observed:E. × pseudovirgata(Schur) Soó,E. esulaL. # EPHES,E. uralensisFisch. ex Link.,E. agrariaM. Bieb., andE. cyparissiasL.
Influence of Buthidazole, Diuron, and Atrazine on Some Light Reactions of Photosynthesis
Authors: Devlin Robert M. , Murkowski Antoni J. , Zbieć Irena I. , Karczmarczyk Stanislaw J. , Skórska Elzbieta M.
Published: May 2019

The influence of buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone}, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] on fluorescence emission and post-luminescence decay in chlorella (Chlorella vulgarisBeyer) was studied. All three herbicides blocked photosynthetic electron transport and thus enhanced fluorescence. Buthidazole was the most active, a 79% increase in fluorescence being observed when algal cultures were exposed to 1 × 10-6M herbicide for 5 min, and a 206% increase with an exposure time of 60 min. Postluminescence in chlorella exposed to 1 × 10-6M buthidazole for 5, 10, 20, and 60 min was inhibited 15, 34, 58, and 69%, respectively. Diuron and atrazine inhibition of postluminescence was much less than that of buthidazole. The ratio of relative fluorescence to relative postluminescence can be sued to give a numerical value (C) for the phytotoxicity of this type of herbicide to a given plant species.
L'ESPANSIONE DEL WELFARE STATE IN EUROPA OCCIDENTALE: 1900–1975
Authors: Alber Jens
Published: May 2019

Introduzione

La precedente indagine sull'origine del welfare state in Europa Occidentale ha mostrato come la variante delle teorie pluraliste conflittuali che si rifà alla weberiana Herrschaftstheorie sia il modello interpretativo più valido per la comprensione della fase emergente delle assicurazioni sociali. Quest'ultima è stata perciò definita come una fase di politica sociale «dall'alto», caratterizzata dallo sforzo da parte del potere politico di integrare i lavoratori in seno all'ordine sociale borghese e allo stato autoritario. L'introduzione dei sistemi statali di assicurazione sociale costituisce tuttavia solo un momento nello sviluppo dello Stato del benessere. Resta quindi da vedere se gli interessi delle élites politiche abbiano influenzato in maniera più determinante rispetto alle rivendicazioni organizzate della classe operaia o alla pressione di problemi socio-economici anche i momenti successivi di tale sviluppo.
SUL GRADO DI PROPORZIONALITÀ DI ALCUNE FORMULE ELETTORALI
Authors: Lijphart Arend
Published: May 2019

Introduzione

Nella letteratura sui sistemi elettorali è ben consolidata l'idea che la rappresentanza proporzionale (R.P.) abbia in genere maggior successo nel raggiungere il suo obiettivo principale — una trasformazione ragionevolmente proporzionale dei voti in seggi — soprattutto rispetto alle formule maggioritarie a uno o due turni. Una delle «proposizioni differenziali» di Douglas W. Rae è che «le formule di rappresentanza proporzionale tendono a distribuire i seggi in modo più proporzionale delle formule maggioritarie». È altrettanto noto che le diverse formule di R.P. non sono proporzionali nella stessa misura, ma gli studiosi sono in disaccordo su quali di esse siano più proporzionali e quali meno.
GLI OBIETTIVI DEL CONTROLLO CENTRALE. PER UN'ANALISI COMPARATA DELLE RELAZIONI TRA CENTRO E PERIFERIA
Authors: Dente Bruno
Published: May 2019

Introduzione

Alla base del rinnovato interesse per lo studio dei rapporti tra governi centrali e governi periferici nelle democrazie occidentali stanno una serie di considerazioni differenti. Da un lato, vi è la convinzione che le tendenze verso l'accentramento, fino a pochi anni or sono apparentemente destinate ad un inevitabile successo, hanno incontrato ed incontrano ostacoli di non poco conto. Sicché il risultato a medio e lungo termine appare tutt'altro che scontato. Tendenze decentralizzatrici, nella forma di regionalizzazioni o di rafforzamento dei governi locali, sono emerse un po’ dappertutto, ed è più che dubbio che il risultato finale sarà quel sistema centralizzato e tecnocratico che molti osservatori preconizzavano (e paventavano) alcuni anni or sono. D'altro lato, proprio per l'insopprimibile vitalità dei governi sub-nazionali, in molti paesi si è affacciata la convinzione che le relazioni tra livelli di governo costituiscono uno dei principali elementi di crisi del moderno welfare state, e in buona sostanza della sua ingovernabilità. Siano i governi locali identificati come una delle cause principali della lievitazione delle spese pubbliche oppure, al contrario, sia la complicazione dei rapporti tra amministrazioni centrali e amministrazioni periferiche posta sotto accusa come causa di ritardi e inefficienze nella attuazione delle politiche pubbliche, il risultato non cambia: studiare i rapporti tra livelli di governo sembra una delle indicazioni principali delle moderne scienze politiche ed amministrative.
I VALORI POSTMATERIALISTI DIECI ANNI DOPO
Authors: Cartocci Roberto
Published: May 2019

Introduzione

Nella seconda metà degli anni ‘70, sotto la direzione di Giovanni Sartori e Alberto Marradi è stata condotta la sezione italiana di un'indagine internazionale su «Insoddisfazione, protesta e mutamento nelle società post-industriali», i cui risultati sono stati commentati più volte su questa rivista. Il disegno di tale ricerca prevedeva ampio spazio per l'analisi degli orientamenti dei giovani, in particolare alla luce del tema della «rivoluzione silenziosa», avanzato da Ronald Inglehart. Con tale formula suggestiva il politologo americano aveva sintetizzato la novità, rispetto al consueto panorama politico, costituita dai movimenti di contestazione giovanile della fine degli anni ‘60.
STATI UNITI E COMUNITÀ EUROPEA: CONFLITTO O COOPERAZIONE?
Authors: Revilla Claudio Cioffi
Published: May 2019

Introduzione

La Comunità europea (CE) e la sua integrazione rappresentano un punto di svolta significativo nello sviluppo politico-internazionale dell'ultimo dopoguerra. È da anni che il complesso sistema della CE è oggetto di ricerca da parte di studiosi e, in particolare, il tema delle relazioni esterne e della politica estera della Comunità e dei suoi membri ha ricevuto notevole attenzione. In questo ambito, l'importanza delle relazioni politiche fra i membri della CE e gli Stati Uniti è ben stabilita, dato il ruolo svolto da questi nel favorire la genesi del sistema CE. Tuttavia, malgrado la rilevanza riconosciuta a questo macro-evento politico, un'analisi comportamentistica degli effetti dell'integrazione euroepa sulle relazioni euro-americane, non è stata ancora condotta.
GOVERNO, PRIMO MINISTRO, ALTA AMMINISTRAZIONE
Authors: Lombardo Antonio
Published: May 2019

Introduzione

Nel dibattito scientifico e politico in Italia e sull'Italia, nei primi anni Ottanta, viene sovente indicata l'esigenza di rafforzare e modernizzare il sistema di governo. A connotare il problema s'è anche coniato e diffuso un neologismo: «governabilità». In questo scritto prendo, innanzi tutto, in esame le più significative proposte di riforma del sistema di governo, che richiedono modifiche costituzionali. Non mi occupo, quindi, di quelle riforme, pure suscettibili di incidere sul sistema complessivo di governo, che non richiedono per la loro attuazione modifiche della Costituzione, come le possibili riforme elettorali. Considero, invece, alcune proposte volte a cambiare i modi di elezione e i poteri del Capo dell'Esecutivo, o l'intero sistema costituzionale di Governo.
SCHUMPETER E LA SCIENZA POLITICA
Authors: Urbani Giuliano
Published: May 2019

Introduzione

Nell'anno appena trascorso non sono mancate opportune celebrazioni critiche del pensiero schumpeteriano, in coincidenza con il centenario della nascita dell'illustre economista austriaco. Stupisce però, e non poco, la quasi completa assenza di riflessioni altrettanto approfondite sui suoi lavori politici, o meglio sulle ampie e frequenti «aree politiche» delle sue trattazioni teoriche. Lo faccio notare, perché mi sembra che tale sottovalutazione finisca col nuocere considerevolmente alla migliore comprensione dell'intera opera schumpeteriana: un'opera, a dire poco, «poliedrica», dove ciascuna faccia si presenta intimamente legata ad ogni altra, tanto da richiedere un'analisi per lo più multidisciplinare.
PROBLEMI E SOLUZIONI IN POLITICA
Authors: Sjöblom Gunnar
Published: May 2019

Introduzione

In questo articolo sosterremo:

a) che implicitamente nozioni come ‘problemi’ (dell'attore) e ‘risolvere problemi’ (degli attori) sono centrali in scienza politica, e
Changing Planning Perspectives of Agricultural Development in Malaysia
Authors: Rudner Martin
Published: May 2019

Malaysia's planning organization has become the institutional centrepiece of that country's development effort. Indeed, Malaysia ranks as one of the non-Communist developing countries where planning is most highly institutionalized. Malaysian planning evolved as an effective policy mechanism for directing the authoritative allocation of public resources towards declared developmental objectives. Despite this attachment to national planning, Malaysia remains a staunchly market-oriented, open, and predominantly private enterprise economy. Nevertheless, as the role of planning expanded, private sector activity became increasingly subject to policy interventions predicated upon the politically-determined goals of development planning.
The Expansion of Europe: A View from America
Authors: Irwin Graham W.
Published: May 2019

A couple of generations ago the historical process known as “the expansion of Europe” was regarded as a blessing for the whole human race. This, at least, was the majority view. Nationalists in the colonies held contrary opinions, hut what they said carried little weight in Europe. For four hundred years, the historians of the age of classical imperialism believed, Europe had been the giver, the colonial world the receiver. The mother-lands had “wrestled with the task of sharing their own civilization with the backward races of the globe”. A good start had been made, but there was much still to be done, and the duty of the colonized peoples was plain: they must continue to serve their apprenticeship until such time as they were ready to join the family of nations. Europe alone held the keys to law and order, advanced technology, efficiency in government, and the potential for progress. In its hand lay the future of the world. In the imperial age, few European historians, even those opposed to imperialism, doubted that the colonies would be ruled for a long time, perhaps indefinitely, by Europe.
A Quotient of Awareness
Authors: Kearins J.
Published: May 2019

Since the development of psychological assessments of ‘intelligence’ at about the beginning of this century, many groups of people have been tested. By and large, most have performed at lower levels than people of north-western European origin or ancestry, who belong to the culture within which the tests were devised.

Among the poor performers, with average IQ’s of 80 to 92, have been people of southern and eastern Europe and Caucasian people from further east (Greeks, Yugoslavs, Iranians, Iraqis, Turks, Indians), tested in their homelands, mostly in large numbers and by compatriots, on ‘standard’ non-verbal or translated tests.

These relatively poor performances demonstrate the extent of cultural learning of a particular type involved in most cognitive tests. Presumably, north-western European cultural learning is required for good performances on tests coming from this cultural background, so that children from different backgrounds, even those from other areas of Europe, are likely to be disadvantaged.

Children from more widely different backgrounds, such as those from hunting and gathering groups, can be expected to be disadvantaged even further.

Nevertheless, hunting and gathering people have been tested on Western-type tests, and poor performances interpreted as indicating inferior ability. Kalahari ‘bushmen’ people in the 1930s were assigned a mean mental age of 7.5 by Porteus as a result of their performance on his Maze Test.

In the same period, Aboriginal people of north-west Australia performed poorly on this test, with ages ranging from 8.22 years to 12.17 years for adults. Aboriginal people have performed poorly, but not invariably so, on other tests.
“Americans and Their Guns”: Civilian Military Organizations and the Destabilization of American National Security
Authors: Kaufman Jason
Published: May 2019

“The Second Amendment is there as a balance of power. It is literally a loaded gun in the hands of the people held to the heads of government.”

—NRA field representative Fred Romero, 1990

The right to bear arms is one of the most controversial issues in United States history; it has always been so, though not for the reasons usually cited by contemporaries. It has been customary since at least the late nineteenth century to view military organizations as an extension of the legitimate authority of the state (except in case of unsanctioned resistance). The American experience, however, gives lie to the assumption that there is a clean analytical divide between state and civil society when it comes to military matters.
Silence of the Land: On the Historical Irrelevance of Territory to Congressional Districting and Political Representation in the United States
Authors: Rehfeld Andrew
Published: May 2019

Every ten years, the United States “constructs” itself politically. On a decennial basis, U.S. Congressional districts are quite literally drawn, physically constructing political representation in the House of Representatives on the basis of where one lives. Why does the United States do it this way? What justifies domicile as the sole criteria of constituency construction? These are the questions raised in this article.

Contrary to many contemporary understandings of representation at the founding, I argue that there were no principled reasons for using domicile as the method of organizing for political representation. Even in 1787, the Congressional district was expected to be far too large to map onto existing communities of interest. Instead, territory should be understood as forming a habit of mind for the founders, even while it was necessary to achieve other democratic aims of representative government.
The Production Structure of Pennsylvania Dairy Farms
Authors: Grisley William , Gitu Kangethe W.
Published: May 2019

The production structure of a selected cross-section sample of family owner-operated dairy farms is investigated using a translog variable cost function. Elasticities of scale, input substitution, and input own- and cross-price elasticities are estimated. At the sample mean herd size of 67 cows producing at 15,173 pounds of milk per cow, the elasticity of scale parameter was 1.00, implying constant returns to scale. The elasticities of substitution between feeds and hired labor and the own- and cross-price elasticities were inelastic.
Social Skills Training for the Handicapped in Mainstream Classrooms
Authors: Gannon Paul
Published: May 2019

This paper argues strongly that the survival of handicapped students in mainstream classes depends essentially on good teacher-student and peer-to-peer social interactions. Supporting empirical evidence is provided and the essential approach needed to facilitate the required interactions is outlined.
Legal Rights and Wrongs of Special Education
Authors: Hayes Robert
Published: May 2019

What kind of legal scene will the special educator face in the 1990’s? It will be a scene whose genesis was in the bright idealism of the 1960’s. It will be marked by much greater accountability by the teaching profession for its mistakes and shortcomings than is possible under existing legal mechanisms. It will be marked by much greater public scrutiny and influence over educational policy making than is possible under the last vestiges of the Westminster system by which we are presently governed. It will be marked by greater use of the federal education funding power to achieve observance of human rights in the educational context, for both public and private sectors, than is at present politically possible. And it will be marked by the introduction of a wide range of external policing authorities, acting as watch dogs for students’ and parents’ human and legal rights.
Research Needs in the Education of Visually Handicapped Children in New Zealand: Address to National Conference, New Zealand Association of the Blind and Partially Blind – Auckland, August, 1983
Authors: Wilton Keri
Published: May 2019

The need for capable, dedicated, and well trained teachers in special educational facilities for visually handicapped children is, and has always been crucial for the effective operation of those facilities. At the same time, the need for the above mentioned qualities in teachers of visually handicapped children has become more apparent in recent years, in the light of various changes which have occurred in the context of special educational services generally. These changes have also strongly affected the direction and scope of special educational research (Wedell & Roberts 1982).
Serum 25-hydroxyvitamin D is associated with obesity and metabolic parameters in US children
Authors: Fu Zhi , Xu Cheng , Shu Yaqin , Xie Zongyun , Lu Changgui , Mo Xuming
Published: May 2019

Objective:

To explore the relationships of serum 25-hydroxyvitamin D (25(OH)D) with obesity and metabolic parameters in US children.

Design:

Cross-sectional analysis. We evaluated the associations between serum 25(OH)D and multiple measurements of adiposity, serum lipid concentrations, fasting glucose and insulin resistance in children aged 6–18 years with adjustments for multiple covariates.

Setting:

The National Health and Nutrition Examination Survey, 2001–2006.

Participants:

A nationally representative sample of 6311 children and adolescents aged 6–18 years.

Results:

Among US children and adolescents, the prevalence of vitamin D deficiency has been especially high in older children, girls and the non-Hispanic Black population. Higher odds of obesity were found at a 25(OH)D concentration of <30 nmol/l (deficiency) than at >50 nmol/l under both criteria for obesity in children (OR = 3·27, Ptrend ≤ 0.001). Moreover, increased odds of having abnormal HDL-cholesterol (OR = 1·71, Ptrend ≤ 0.001) and impaired insulin resistance (OR = 4·15, Ptrend ≤ 0·001) were found for children deficient in 25(OH)D compared with those with normal 25(OH)D concentrations. When the children and adolescents were stratified by gender, we found stronger associations between serum 25(OH)D concentration and both HDL-cholesterol and insulin resistance in girls. No association of 25(OH)D with any other metabolic parameter was found.

Conclusions:

Our results suggest a potential harmful association between low serum 25(OH)D concentration and the risk of obesity among children. However, the underlying mechanisms require further investigation.
Introduction
Authors: BOWN CHAD P. , MAVROIDIS PETROS C.
Published: May 2019

The WTO dispute settlement system has come under severe criticism in recent times, which does not seem, for now at least, to affect its relevance. In terms of output, 2017 was yet another bumper year. We review eight cases that constitute the ‘last word’ of the dispute settlement system: we review exhaustively all Appellate Body reports, as well as all un-appealed panel reports.
Improvements in the GISTEMP Uncertainty Model
Authors: Lenssen Nathan J. L. , Schmidt Gavin A. , Hansen James E. , Menne Matthew J. , Persin Avraham , Ruedy Reto , Zyss Daniel
Published: May 2019

We outline a new and improved uncertainty analysis for the Goddard Institute for Space Studies Surface Temperature product version 4 (GISTEMP v4). Historical spatial variations in surface temperature anomalies are derived from historical weather station data and ocean data from ships, buoys, and other sensors. Uncertainties arise from measurement uncertainty, changes in spatial coverage of the station record, and systematic biases due to technology shifts and land cover changes. Previously published uncertainty estimates for GISTEMP included only the effect of incomplete station coverage. Here, we update this term using currently available spatial distributions of source data, state‐of‐the‐art reanalyses, and incorporate independently derived estimates for ocean data processing, station homogenization, and other structural biases. The resulting 95% uncertainties are near 0.05 °C in the global annual mean for the last 50 years and increase going back further in time reaching 0.15 °C in 1880. In addition, we quantify the benefits and inherent uncertainty due to the GISTEMP interpolation and averaging method. We use the total uncertainties to estimate the probability for each record year in the GISTEMP to actually be the true record year (to that date) and conclude with 87% likelihood that 2016 was indeed the hottest year of the instrumental period (so far).
Tidal and Thermal Stresses Drive Seismicity Along a Major Ross Ice Shelf Rift
Authors: Olinger S. D. , Lipovsky B. P. , Wiens D. A. , Aster R. C. , Bromirski P. D. , Chen Z. , Gerstoft P. , Nyblade A. A. , Stephen R. A.
Published: May 2019

Understanding deformation in ice shelves is necessary to evaluate the response of ice shelves to thinning. We study microseismicity associated with ice shelf deformation using nine broadband seismographs deployed near a rift on the Ross Ice Shelf. From December 2014 to November 2016, we detect 5,948 icequakes generated by rift deformation. Locations were determined for 2,515 events using a least squares grid‐search and double‐difference algorithms. Ocean swell, infragravity waves, and a significant tsunami arrival do not affect seismicity. Instead, seismicity correlates with tidal phase on diurnal time scales and inversely correlates with air temperature on multiday and seasonal time scales. Spatial variability in tidal elevation tilts the ice shelf, and seismicity is concentrated while the shelf slopes downward toward the ice front. During especially cold periods, thermal stress and embrittlement enhance fracture along the rift. We propose that thermal stress and tidally driven gravitational stress produce rift seismicity with peak activity in the winter.