bluuebunny/crossref_metadata_2025 huggingface dataset:
Mud deposition and diagenesis within an Early Palaeozoic clinothem: Power Steps Formation, Newfoundland, Canada
Authors: Denommee Kathryn C. , Harazim Dario , Bentley Samuel J. , Macquaker James H. , Lode Stefanie , Olanipekun Babatunde John
Published: May 2019

The early Ordovician (∼385 Ma) Power Steps Formation, Newfoundland, Canada, exposes a well-preserved mudstone-dominated clinothem that serves as an excellent archive for understanding how mud has been produced, transported and converted into mudstone prior to the evolution of globally widespread, deep soil horizons. Sedimentological analysis of four sandstone and five mudstone facies, along the Ochre Cove clinothem, reveal that mud and sand were delivered by unidirectional currents and experienced episodic reworking by storm waves. Petrographic examination and X-ray diffraction from described mudstone facies reveal significant variability in the distribution of illite versus chlorite between the lower and upper part of the Ochre Cove clinothem. This research highlights that in the present-day clay mineral fraction, illite is often detrital whereas chlorite originated via the alteration of silt-sized, highly unstable, mafic (volcanoclastic?) grains. Throughout all sedimentologic facies, albeit in different proportions, these mafic lithic grains were diagenetically altered viain situweathering before significant compaction occurred, resulting in the precipitation of significant volumes of pore-bridging, silica- and iron-rich chlorite cement. Compositional, diagenetic and textural attributes across the Ochre Cove mud clinothem vary as a function of starting composition, hydrodynamic sorting and grain density. Given that a significant proportion of clay minerals has been generated viain situtransformation of a mafic, non-stable precursor assemblage, we recommend future studies to incorporate detailed petrographic description along with X-ray diffraction analyses when aiming to employ trends in whole-rock clay mineral data as a proxy in provenance and palaeoclimate studies of very old (pre-Devonian) mudstones and sandstones.
The Right to Demonstrate: A Comparative Study of Israel and the United States
Authors: Raffel Martin J.
Published: May 2019

The right of the citizen to express his views publicly is a basic feature of the democratic system. However, the freedom of expression, and the closely related freedom of public assembly, do at times conflict with other major social interests. As a result, no society has accepted the theory that these freedoms should be absolute. The democratic process requires a balancing of these freedoms with other important values and public interests. Consequently, each state has placed various limitations on the freedom of expression and public assembly. If a government limits these freedoms too much, it may do irreparable damage to the democratic process. Likewise, the fact that the freedom is enshrined in some constitutional document does not ensure that it will be given any meaningful protection. Whether or not fundamental freedoms are really preserved, is the true test of a democracy.

Demonstrations have traditionally been used as a vehicle for expressing dissent. A citizen who is generally satisfied with the social and politicalstatus quowill probably not feel a need to exhibit his satisfaction publicly.
A New Dimension in Collective Agreements
Authors: Ben-Israel Ruth
Published: May 2019

From the late 19th century on, a series of social and economic changes have altered the system of labour relations. The transition of bargaining over terms of employment, from the individual to the collective sphere, was the culmination of the historical stages of development. Changes in labour relations have always been, and remain dynamic. Therefore, collective labour law, like the industrial relations system itself, is constantly taking new steps to formulate up-to-date patterns of thought and behaviour. Hence, the legal system finds it difficult to dictate firm policies, and can only try to catch up with the development bypost factumlegislation and theorization, which can set but a broad and flexible framework.

The collective agreement is presented in this study as a universal phenomenon, resulting from the historical stages of development in labour relations. These stages have led to the crystallization of the collective agreement as it is known today, and to the formulation of its distinctive traits.
The Legal Condition of the Jews Under the Visigothic Kings Part III
Authors: Juster Jean
Published: May 2019

We know nothing of the local organization of the Jews in the Visigothic kingdom. It seems likely that their communities (called conventus in the statutes) preserved the same framework as they had had under the Roman rule. Recognized by law as long as the Jewish cult was licit, the Jewish communities were to be deprived of their legal existence by those kings who compelled the Jewish to baptism.

Thus we have no information about their internal organization during either the Arian or Catholic regimes, save for some fragmentary data which have reached us concerning two Jewish communal institutions.
Lifetime prevalence and potential determinants of psychotic experiences in the general population of Qatar
Authors: Khaled Salma M. , Wilkins Stacy Schantz , Woodruff Peter
Published: May 2019

Background

To estimate the lifetime prevalence and potential determinants of psychotic experience(s) (PEs) in the general population of Qatar – a small non-war afflicted, conservative, high-income, middle-eastern country with recent rapid urbanization including an influx of migrants.

Methods

A probability-based sample (n = 1353) of non-migrants and migrants were interviewed face-to-face and administered a 7-item psychosis screener adapted from the Composite International Diagnostic Interview, the Kessler 6-item psychological distress scale, and the 5 items assessing odd (paranormal) beliefs and magical thinking (OBMT) from the Schizotypal Personality Questionnaire. Using bivariate and logistic regression analyses, lifetime prevalence rates of PEs were estimated then compared before and after adjustment for socio-demographics, Arab ethnicity, psychological distress, and OBMT.

Results

Prevalence of PEs was 27.9%. Visual hallucinations were most common (12.8%), followed by persecutory delusions (6.7%) and auditory hallucinations (6.9%). Ideas of reference (3.6%) were least prevalent. PEs were significantly higher in Arabs (34.7%) compared with non-Arabs (16.4%, p < 0.001) with the exception of ideas of reference and paranoid delusions. Female gender was associated with a higher prevalence of PEs in the Arab group only (p < 0.001). Prevalence of PEs was significantly higher among Arabs (48.8% v. 15.8%, p < 0.001) and non-Arabs (35.2% v. 7.3%, p < 0.001) with OBMT. Arab ethnicity (OR = 2.10, p = 0.015), psychological distress (OR = 2.29 p = 0.003), and OBMT (OR = 6.25, p < 0.001) were independently associated with PEs after adjustment for all variables.

Conclusions

Ethnicity, but not migration was independently associated with PEs. Evidence linking Arab ethnicity, female gender, and psychological distress to PEs through associations with OBMT was identified for future prospective investigations.
Techniques for Greenhouse Evaluation of Herbicides on Saltcedar
Authors: Quimby P.C. , Hollingsworth E.B. , McDonald R.L.
Published: May 2019

Subirrigated pot-plant systems were developed for greenhouse simulations of field methods being tested for herbicidal control of saltcedar (Tamarix pentandraPall.). The methods included: over-the-top spraying; soil injection; soil layering, with whole plants transplanted onto the herbicide layer; and soil layering by severing the roots and concomitantly injecting herbicide. Existing foliar application techniques were improved for greenhouse testing of herbicides and results from preliminary tests were apparently similar to literature reports of limited efficacy in the field. Preliminary results from these greenhouse techniques showed that root zone applications, either by soil layering or soil injection, were very effective; stem or foliar applications were less effective.
Influence of Postemergence and Subsurface Layered Herbicides on Horsenettle and Peanuts
Authors: Banks P.A. , Kirby M.A. , Santelmann P.W.
Published: May 2019

Postemergence herbicide treatments that were most effective for controlling horsenettle (Solarium carolinense L.) were glyphosate [N-(phosphonomethyl)glycine], dicamba (3,6-dichloro-o-anisic acid), silvex [2-(2,4,5-trichlorophenoxy)-propionic acid], and picloram (4-amino-3,5,6-trichloropicolinic acid). All exhibited good to excellent long term control of the horsenettle plant when applied annually for at least 2 yr. Picloram and glyphosate both provided better control of horsenettle when applied at a postbloom or fruiting stage of growth. Dicamba and picloram also were very effective in controlling horsenettle when used as a subsurface layer (SSL) treatment. However, all of these treatments caused visual injury to peanuts (Arachis hypogaea L.). Applications of 2,4-DB [4-(2,4-dichorophenoxy)butyric acid] were effective in causing an 80 to 90% fruiting inhibition of horsenettle plants when applied at a prebloom stage of growth, with no damage to the peanuts. Applications of several dinitroaniline herbicides as SSL treatments exhibited some control of horsenettle with little crop injury. Postemergence treatments which effectively controlled seedling horsenettle plants grown in the greenhouse were glyphosate and dinoseb (2-sec-butyl-4,6-dinitrophenol).
Metabolism of Sandoz 6706 in Soybean and Sicklepod
Authors: Motooka P.S. , Corbin F.T. , Worsham A.D.
Published: May 2019

The metabolism of Sandoz 6706 [4-chloro-5-(dimethylamino)-2-α,α,α-trifluoro-m-tolyl-3(2H)-pyridazinone] in soybean [Glycine max(L.) Merr. ‘Kent’] and in sicklepod (Cassia obtusifoliaL.) was examined at 1, 2, 4, and 8 days after herbicide application to explain the relative susceptibility of soybean and sicklepod to the herbicide. The14C-labeled Sandoz 6706 was applied via the plant roots in a liquid culture medium. The primary pathway of metabolism in both plant species involvedN-demethylation to norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone and the desmethyl Sandoz 9774 [5-amino-4-chloro-2-(α,α,α-trifluoro-m-tolyl-3(2H)-pyridazinone]. Soybean was more efficient in theN-demethylation of the herbicide to less toxic metabolites than was sicklepod. A second transformation pathway which resulted in the formation of polar products was present in the roots of both species.
Metribuzin Persistence in Soil
Authors: Savage K.E.
Published: May 2019

The persistence of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)-one] in several soils from the lower alluvial floodplain of the Mississippi River was studied in the greenhouse and laboratory using bioassay and gas chromatographic methods of residue detection. Bioassay results indicated that metribuzin phytotoxicity was lost in several soil types within a few weeks of application. Longevity of phytotoxicity depended upon soil type. However soil type had little effect on the rate of metribuzin degradation measured chemically. Gas chromatographic techniques indicated that metribuzin degradation followed first-order kinetics with half-life values ranging from 17 to 28 days in six soils under greenhouse conditions. Incubation studies indicated that metribuzin was degraded more rapidly in nonautoclaved field soil and in soil enriched with glucose than in soil that had been air dry for 1 yr or had been autoclaved. Degradation was more rapid at 30 C than at 20 C. Microbiological activity apparently is important in the degradation of metribuzin in soil.
Longevity of Foxtail Taxa in Undisturbed Sites
Authors: Schreiber M. M.
Published: May 2019

Survival of foxtail grass in undisturbed sites was tested in a 4-yr study of robust white foxtail (Setaria viridisvar.robusta-albaSchreiber), robust purple foxtail (Setaria viridisvar.robusta-purpureaSchreiber), giant green foxtail [Setaria viridisvar.major(Gaud.) Posp.], yellow foxtail [Setaria lutescens(Weigel) Hubb.], and giant foxtail (Setaria faberiHerrm.). Regardless of taxa seeded, giant foxtail dominated the stand with small amounts of yellow foxtail in the fourth year. Although the foxtail taxa stands corresponded to the taxa seeded in the first year of growth, robust white foxtail, robust purple foxtail, and giant green foxtail completely or nearly disappeared within 4 yr of having been seeded alone or with other taxa, and generally sooner when mixed with giant foxtail. Because of the rapid dominance of giant foxtail, the robust white foxtail, robust purple foxtail, and giant green foxtails are not likely to become a source of seed for infestation from fencerows to production fields.
Germination, Growth, and Development of Spurred Anoda
Authors: Solano Francisco , Schrader J. W. , Coble H. D.
Published: May 2019

Spurred anoda [Anoda cristata(L.) Schlect.] seed germination averaged 0.5 to 3.0% for seeds buried in the field for up to 20 months under natural conditions. These same seeds averaged over 76% germination after scarification with concentrated sulfuric acid, indicating hard seed coat involvement in seed dormancy. Germination was unaffected by light variables but increased as temperature increased. Germination of scarified seed increased from 50% to 85% as temperature was increased from 18 C to 30 C. Spurred anoda developed more slowly than did cotton (Gossypium hirsutumL. ‘Coker 310′) for the first 45 days. After that spurred anoda grew more rapidly until by 60 days after emergence, the weed was larger than cotton as measured by shoot height and total leaf surface area. This difference in development between cotton and spurred anoda indicates postemergence directed sprays of herbicides might be useful as a control tool.
Dissemination of Weed Seeds by Irrigation Water
Authors: Kelley A. D. , Bruns V. F.
Published: May 2019

Irrigation laterals PL.15.LR and S2.15W, in the Yakima Valley of Washington and the Columbia River near Paterson, Washington, were sampled for weed seeds during 1970, 1971, and 1973–74, respectively. Weekly or biweekly screenings of the water in the three systems during the irrigation season yielded seeds of 137, 84, and 77 plant species, respectively. In the same order, the total number of seeds per 254 kl of water averaged 2,220, 682, and 292 for the season. Moreover, if the seeds were evenly distributed in the average amount of water used to irrigate the land during the season, the number of seeds disseminated would average 94,500, 10,400, and 14,100 per hectare. Weed control practiced by water users along certain sections of S2.15W markedly reduced both the kind and number of weed seeds found in the water when compared with PL.15.LR on which no weed control measures were used.
Influence of Climate and Additives on Bentazon
Authors: Nalewaja John D. , Pudelko Jerzy , Adamczewski K. A.
Published: May 2019

Experiments were conducted in the growth chamber and greenhouse to determine the influence of humidity, temperature, simulated rainfall, and oil additives with bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2,2-dioxide] upon redroot pigweed (Amaranthus retroflexusL.) control. Generally, bentazon gave increased redroot pigweed control with high rather than low humidity. However, the increased weed control with high humidity was greater at 10 C than at 20 or 30 C. A simulated rainfall within 24 hr after bentazon application reduced redroot pigweed control. A simulated rainfall of 650 L/ha within 1.5 hr after bentazon application increased control of redroot pigweed, while more than 1300 L/ha simulated rainfall decreased redroot pigweed control. Emulsifiable linseed oil and petroleum oil additives to the spray reduced the detrimental effect of low humidity and simulated rainfall upon redroot pigweed control with bentazon. Emulsifiable linseed oil was more effective than petroleum oil in reducing the detrimental effect of low humidity and of simulated rainfall. However, emulsifiable linseed oil reduced the redroot pigweed control with bentazon with high humidity at 30 C compared to bentazon applied alone or with petroleum oil.
Effect of Plant Residue on Herbicide Performance in No-Tillage Corn
Authors: Erbach Donald C. , Lovely Walter G.
Published: May 2019

The effect of surface corn (Zea maysL.) plant residue on weed control with atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] or alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide] was studied in the field and greenhouse. Plant residue did not significantly affect weed control when herbicides were applied at recommended rates but had an increased influence on control as herbicide rates were reduced. In the greenhouse, simulated rain improved the control of velvetleaf (Abutilon theophrastiMedic.) and foxtail millet [Setaria italica(L.) Beauv.].
Factors Affecting EPTC Injury to Navy Bean
Authors: Wyse Donald L. , Meggitt William F. , Penner Donald
Published: May 2019

Injury to navy bean (Phaseolus vulgarisL.) from EPTC (S-ethyl dipropylthiocarbamate) was investigated as a function of soil moisture, planting depth, soil compaction, temperature, available nitrogen, and seed quality. Experiments in the greenhouse and growth chamber showed that both high and low moisture stress increased injury. Deep planting increased the injury from high rates of EPTC. Soil compaction alone reduced plant growth. In combination with EPTC at 4.5 kg/ha, further growth reduction was observed. Ambient temperature did not alter susceptibility to EPTC. Stimulation of growth by nitrogen as measured by increased fresh weight was inhibited by EPTC. Field and greenhouse studies showed that EPTC injury was greater to mechanically damaged seed than non-damaged seed.
Relative Volatilities of Ester and Amine Forms of 2,4-D
Authors: Grover R.
Published: May 2019

The relative volatilities of various technical and formulated ester and amine salts of 2,4-D [(2,4-dichlorophenoxy)acetic acid] were determined in a closed air-flow system consisting of a volatilization chamber and an ethylene glycol trap. The system was operated at a flow rate of 28.8 L/hr and a temperature of 30 C. Trapped herbicide vapor was analyzed by gas chromatography. The relative volatilities of technical gradeiso-propyl, butyl, propylene glycol butyl ether, andiso-octyl esters, were 56, 25 to 38, 4, and 1, respectively. The relative volatilities of various formulated esters and amines were of the magnitude of 440:33:1 for the high volatile, low volatile, and amine salts, respectively.
Competition of Florida Beggarweed and Sicklepod with Peanuts II. Effects of Cultivation, Weeds, and SADH
Authors: Buchanan Gale A. , Hauser Ellis W. , Ethredge W. J. , Cecil S. R.
Published: May 2019

When peanuts (Arachis hypogaeaL.) were not kept weed-free, a single cultivation 4 weeks after emergence increased yields substantially over those of non-cultivated peanuts. Cultivation had no effect, however, when peanuts were maintained weed-free for 4 or 8 weeks. The length of the weed-free periods, cultivation, and the presence or absence of peanuts all strongly influenced the density of the sicklepod (Cassia obtusifoliaL.) plants which grew above the canopy of peanut foliage. Peanut foliage, which was released from weed-free maintenance at 8 weeks but then competed with sicklepod until harvest, reduced the green weight of sicklepod 95 to 98% thus illustrating the competitive capacity of the peanut plant. Moderate stands of Florida beggarweed [Desmodium tortuosum(Sw.) DC] did not markedly affect yield of peanuts. Application of a growth regulator, succinic acid, 2,2-dimethylhydrazide (SADH), did not influence weed competition or yield of in-shell peanuts consistently at any of the three locations. Quality analyses showed that treatment variables did not modify the taste of peanuts; however, in some experiments, components of the market grade of in-shell peanuts were changed by SADH, cultivation, length of the weed-free period, and cultivation X length of the weed-free period.
Differential Gas Exchange Responses of Two Biotypes of Redroot Pigweed to Atrazine
Authors: West L. D. , Muzik T. J. , Witters R. E.
Published: May 2019

Differences were shown to exist in photosynthetic rate, transpiration rate, and carbon dioxide leaf diffusive resistance between atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] susceptible (S) and resistant (R) plants of redroot pigweed (Amaranthus retroflexusL.). Chlorbromuron [3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea] and diruon [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were the only herbicides tested that controlled both biotypes, but all of the herbicides except norea [3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea] controlled the S biotype. Although photosynthetic activity and transpiration were reduced in both biotypes by atrazine at 50 and 70 ppm, the decline was much greater in the S biotype than in the R biotype and persisted a longer time in the S biotype. Leaf CO2diffusive resistances of the biotypes were increased by atrazine applications. Mesophyll resistance was increased to a greater extent than stomatal resistance suggesting that reduction of photosynthesis is due to a greater effect of atrazine on the mesophyll tissue than on the guard cells.
Herbicides in the Energy Equation
Authors: Alder E. F. , Klingman G. C. , Wright W. L.
Published: May 2019

A great deal of energy in recent months has been expended in worrying about energy. The procurement, allocation, utilization, and conservation of energy sources have been probed countless times and viewed from almost every possible vantage point. The word “energy” now shares the stage with the word “environment.”
C4Photosynthesis in Smooth Pigweed
Authors: Patterson David T.
Published: May 2019

The response of net photosynthetic rate to temperature and light, the rate of photorespiration, the compensation concentration for CO2, and the pathway of CO2fixation in smooth pigweed (Amaranthus hybridusL.) were investigated using infrared gas analysis and14CO2. Maximum net photosynthetic rates of whole shoots were 45 mg CO2dm-2hr-1at 30 C and 7.8 klux. Intact whole shoots were not light saturated at 10 klux. The optimum temperature for net photosynthesis was between 30 C and 40 C. Photorespiration was low and the CO2compensation concentration was 7 ppm. After a 5-sec exposure to14CO2in the light, label was detected in oxaloacetate, malate, and aspartate. It was concluded that smooth pigweed has the gross photosynthetic characteristics and CO2fixation pathway typical of C4or Hatch-Slack plants.
Effects of Nitrogen with Trifluralin and Vernolate on Soybeans
Authors: Parker M. B. , Dowler Clyde C.
Published: May 2019

Rates of trifluralin (α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and vernolate (S-propyl dipropylthiocarbamate) were compared with and without 45 kg/ha of nitrogen for 2 yr on soybeans [Glycine max(L.) Merr.]. Nodulation was the only factor affected significantly by nitrogen. Nodule weight was 65% greater where nitrogen was not applied. Nodulation was suppressed by trifluralin, but not by vernolate. Delays in emergence, stunting, plant injury, and yield reduction were associated with preplant incorporated treatments of trifluralin at 1.12 kg/ha and with incorporated vernolate at 2.24 and 4.48 kg/ha. Trifluralin incorporated at 0.56 kg/ha and vernolate injected at 2.24 and 4.48 kg/ha had essentially no effect on plant injury and did not reduce yields significantly. Soybeans were injured more by incorporated vernolate than by trifluralin. Average yields of weed-free soybeans for 2 yr were reduced 10.5, 8.6, and 14.0%, respectively, by (a) trifluralin at 1.12 kg/ha and (b) incorporated vernolate at 2.24 and 4.48 kg/ha. However, injected vernolate (compared to other treatments) significantly increased soybean emergence, reduced plant injury, and increased yields.
Glyphosate for Weed Control in Dormant Bermudagrass
Authors: Johnson B. J.
Published: May 2019

The control of winter annuals in dormant bermudagrass [Cynodon dactylon(L.) Pers. ‘Common’] has not been consistent with available herbicides. Experiments were conducted to evaluate rates and number of glyphosate [N-(phosphonomethyl)glycine] applications for control of winter annuals growing in dormant bermudagrass. Glyphosate applied as a single treatment at 0.6 kg/ha consistently controlled more parsley-piert (Alchemilla microcorpaBoissier Reuter), corn speedwell (Veronica arvensisL.), and henbit (Lamium amplexicauleL.) than paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) or combination treatments of 2,4-D [(2,4-dichlorophenoxy)acetic acid) + mecoprop 2[(4-chloro-o-tolyl)oxy] propionic acid + dicamba (3,6-dichloro-o-anisic acid). There was no difference between glyphosate and paraquat control of annual bluegrass (Poa annuaL.) and common chickweed [Stellaria media(L.) Cyrillo]. Glyphosate treatments did not injure the bermudagrass the following spring.
Douglas Fir Release from Tanoak and Pacific Madrone Competition
Authors: Radosevich S. R. , Passof P. C. , Leonard O. A.
Published: May 2019

Broadleaf species such as tanoak [Lithocarpus densiflorus (Hook. & Arn.) Rend.] and pacific madrone (Arbutus menziezii Pursh) reduced conifer growth on previously logged or burned areas of the northern California and southwest Oregon coast range. Cut-surface applications of 2,4-D [(2,4-dichlorophenoxy)acetic acid], 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], and picloram (4-amino-3,5,6-trichloropicolinic acid) into tanoak and pacific madrone growing as overstory to Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] were found to provide acceptable control for 10 years following application. Increment cores obtained from Douglas fir in treated and non-treated plots revealed substantial stem enlargement as a result of tanoak and pacific madrone control.
Glyphosate Translocation and Quackgrass Rhizome Bud Kill
Authors: Claus J. S. , Behrens R.
Published: May 2019

The effect of quackgrass [Agropyron repens (L.) Beauv.] rhizome length and foliage height on glyphosate [N-(phosphonomethyl)glycine] translocation was determined on the basis of bud kill and 14 C-accumulation in quackgrass rhizomes. Foliar glyphosate treatments of 0.28 kg/ha resulted in significantly reduced quackgrass rhizome bud survival, and rates of 0.56, 0.84, and 1.12 kg/ha gave nearly complete bud kill. Rhizome buds on glyphosate-treated quackgrass plants with 20 to 90 nodes had a higher survival rate than rhizome buds on plants with 10 nodes. Quackgrass bud kill was greatest when glyphosate was applied to taller foliage. When all rhizome buds were not killed, those closest to the mother shoot survived glyphosate treatments. The 14C accumulation following applications of 14C-glyphosate was greatest in nodes near the rhizome tip and least in nodes near the mother shoot. This suggests that greater bud kill near the rhizome tip was due to larger accumulation of glyphosate in this part of the rhizome.
Behavior and Fate of Metribuzin in Eight Ontario Soils
Authors: Sharom M. S. , Stephenson G. R.
Published: May 2019

The adsorption, desorption, and mobility of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] in eight Ontario soils were investigated. The distribution coefficients varied from 0.56 for the least adsorptive Fox sandy loam soil to 31.67 for the most highly adsorptive Leamington muck soil. Most of the adsorbed metribuzin was desorbed from the mineral soils after six aqueous extractions, however substantial amounts of the herbicide remained adsorbed on the muck soils after 10 aqueous extractions. The herbicide was relatively mobile in mineral soils but was immobile in the muck soils. Mobility was inversely correlated with the amount of soil organic matter. Bioassay studies indicated that phytotoxicity of metribuzin also decreased with increasing organic matter content of the soil. Persistence of metribuzin was dependent on microbial degradation. In a field study with Guelph loam, the half-life of metribuzin was approximately 3 months.
Area-of-Influence of Herbicide Granules
Authors: Erbach D. C. , Lovely W. G. , Bockhop C. W.
Published: May 2019

The area influenced by individual herbicide granules was determined by rating control of weeds planted in fixed patterns around granules. The area of foxtail millet [Setaria italica(L.) Beauv.] controlled by alachlor [2-chloro-2′,6′diethyl-N-(methoxymethyl) acetanilide] was larger than the area of velvetleaf (Abutilon theophrastiMedic.) controlled by atrazine [2-chloro-4(ethylamino)-6-(isopropylamino)-s-triazine]. Control was most consistent when granules and seeds were near the same depth and was most variable when granules were on the soil surface. Control of foxtail millet with alachlor increased with increasing soil moisture, with decreasing granule depth, and with increasing seed depth. At low soil moisture, control of velvetleaf with surface-applied atrazine was better with simulated rain than with subirrigation. When soil moisture was high and atrazine granules were placed 1-cm deep, control was better with subirrigation. The area-of-influence, or the control (y) as function of distance (x) from granule, was described by y = 10e-A(x-B)2. The radius-of-control (ROC), defined as the radius of the circular area around a granule within which weeds are effectively controlled, was estimated from this relationship.
Effect of Picloram on Organogenesis in Detached Leaves ofEcheveria elegansBgr.
Authors: Raju M. V. S. , Grover R.
Published: May 2019

The effect of picloram (4-amino-3,5,6-trichloropicolinic acid) on regeneration of detached leaves ofEcheveria elegansBgr. was studied. Picloram stimulated callus production at all concentrations. Low concentrations of 1 to 15 ppmw picloram did not affect shoot organogenesis and the same, however, stimulated rhizogenesis. Inhibition of both root- and shoot-organogenesis was noticeable at concentrations below 20 ppmw and above. Roots increased in number at all picloram concentrations below 40 ppmw, the maximum number being at concentration of 15 to 20 ppmw of the herbicide. Observations indicated that root elongation was considerably suppressed. Picloram-induced callus contained mature parenchyma cells devoid of contents and considerable amount of tissue disruption was noticed. Irregular vascular differentiation and obliteration of tissues particularly in the region of tracheary elements, were obvious. Although normal apical organization was lacking in root primordia and in arrested short roots, these elongated normally into mature roots when they were transferred to water, thus indicating that apical meristems were not severely affected by picloram.
Triallate Accumulation in Wild Oat and Barley
Authors: Thiele G. H. , Zimdahl R. L.
Published: May 2019

Analysis of entire barley (Hordeum vulgare‘Moravian’) seedlings exposed to triallate [S-(2,3,3-trichloroallyl)-diisopropylthiocarbamate] vapor for 5 days after a 5-day germination period resulted in a linear rate of accumulation of triallate, while wild oat (Avena fatuaL.) seedlings accumulated triallate for 1/2 to 2 days after exposure with no net accumulation thereafter. Similar accumulation patterns were shown for a similar exposure period when barley and wild oat were seeded 1.3 cm below a triallate-treated soil layer in the greenhouse. More triallate accumulated in wild oat and barley when they were planted in a triallate-treated soil layer than below. Since barley accumulated greater amounts of triallate without injury than wild oat, differential uptake of triallate was not the reason for selectivity.
Response of Weeds to Soil Phosphorus and Potassium
Authors: Hoveland C. S. , Buchanan G. A. , Harris M. C.
Published: May 2019

Ten warm-season and seven cool-season weed species were grown in the glasshouse on Hartsells fine sandy loam taken from field plots that had been in long-term fertility studies. The soil pH was 5.9 and phosphorus (P) levels ranged from 8 to 95 kg/ha and the potassium (K) levels from 40 to 213 kg/ha. Growth response to P and K levels was measured by dry herbage yield. Redroot pigweed (Amaranthus retroflexus L.), jimsonweed (Datura stramonium L.), and Florida beggarweed [Desmodium tortuosum (Sw.) DC] were the most responsive warm-season weed species to P, whereas chickweed [Stellaria media (L.) Cyrillo] was the most responsive cool-season weed to P. Extreme P deficiency symptoms were evident on species giving a high response to P. P-deficient plants were severely stunted and exhibited a characteristic reddish-purple color. Showy crotalaria (Crotalaria spectabilis Roth), tall morningglory [Ipomoea purpurea (L.) Roth], sicklepod (Cassia obtusifolia L.), Carolina geranium (Geranium carolinianum L.), and coffee senna (Cassia occidentalis L.) were the most tolerant to low soil P. Redroot pigweed, jimsonweed, and Florida beggarweed were the most responsive warm-season weeds to K. Wild mustard [Brassica kaber (DC.) L.C. Wheeler var. Pinnatifida (Stokes) L.C. Wheeler] and annual bluegrass (Poa annua L.) were the most responsive cool-season weeds to K. Potassium deficiency symptoms were characterized primarily by severe stunting. Buckhorn plantain (Plantago lanceolata L.), Carolina geranium, and curly dock (Rumex crispus L.) were the most tolerant cool-season weeds to low soil K. Generally, weeds were more sensitive to low soil-test P than K.
Competition of Velvetleaf, Prickly Sida, and Venice Mallow in Soybeans
Authors: Eaton B. J. , Russ O. G. , Feltner K. C.
Published: May 2019

Weed competition in soybeans [Glycine max(L.) Merr. ‘Clark 63′] with planted stands of velvetleaf (Abutilon theophrastiMedic.), prickly sida (Sida spinosaL.), and Venice mallow (Hibiscus trionumL.) is reported. Weeds were planted 0, 10, 20, 30, and 40 days after soybeans and competed until soybeans matured. Soybean seed yields were reduced 720, 250, and 230 kg/ha by velvetleaf, Venice mallow, and prickly sida, respectively. Weeds that emerged with soybeans reduced yields 1,010 kg/ha. Weeds planted 10 days later reduced yields 480 kg/ha, but weeds planted 20 to 40 days after soybeans did not significantly reduced yield. Soybean yields were reduced regardless of weed placement in or between soybean rows. Weed competition reduced numbers of soybean pods per plant more than other soybean-yield components.
Studies on the Mechanism ofs-Triazine Resistance in Common Groundsel
Authors: Radosevich S. R. , Devilliers O. T.
Published: May 2019

The distribution of simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] in whole plants and the effect of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] on isolated leaf cells and chloroplasts of two biotypes of common groundsel (Senecio vulgarisL.) were studied. Both biotypes accumulated14C at the leaf margins 60 hr after exposure of roots to14C-simazine. No difference in herbicide distribution between the two biotypes was observed. Atrazine (10 μM) inhibited photosynthesis, RNA synthesis, and lipid synthesis in isolated susceptible (S) cells but not resistant (R) cells. Lipid synthesis in S cells but not R cells was enhanced by exposure to 1 and 0.1 μM atrazine for 1 hr. Photochemical activity of R chloroplasts was not inhibited by atrazine but S chloroplasts were severely inhibited.
Herbicides for Container Grown Nursery Stock
Authors: Ryan G. F.
Published: May 2019

Over a 3-yr period 10 herbicides were tested alone or in combination for control of weeds and for effects on growth of nursery stock in containers. Annual bluegrass (Poa annuaL.) was controlled by norea [3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea], alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], and combinations of diphenamid (N,N-dimethyl-2,2-diphenylacetamid), trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), and nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline] plus simazine [2-chloro-4,6-bis(ethylamino)-s-triazine]. Bittercress (Cardamine oligospermaNutt.) was controlled by simazine, oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one], and norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone]. Mouseear chickweed (Cerastium vulgatumL.) was controlled by dichlobenil (2,6-dichlorobenzonitrile) and norflurazon, and common groundsel (Senecio vulgarisL.) was controlled by dichlobenil and norflurazon. Some of the treatments decreased growth of certain nursery cultivars.
Growth Responses of Barnyardgrass and Bearded Sprangletop Seedlings to Benthiocarb
Authors: Shibayama Hidejiro , Worley Joseph F.
Published: May 2019

Benthiocarb S-[(4-chlorophenyl) methyl] diethylcarboamothioate which was applied postemergence, altered the growth and development of shoots of barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and bearded sprangletop [Leptochloa fascicularis (Lam.) Gray] seedlings, two gramineous annual weeds commonly found in rice fields. The herbicide did not affect root development of either species. Benthiocarb retarded the growth of new leaves within the extending leaves and caused swelling of cells. The cells of the shoot apices of treated seedlings were often vacuolated. Tubular-like leaves were induced by benthiocarb, but their formation differed from that caused by phenoxy herbicides.
Regenerative Capacity of Field Bindweed Roots
Authors: Swan D. G. , Chancellor R. J.
Published: May 2019

Lateral roots of a clone of field bindweed (Convolvulus arvensis L.) were dug each month for 12 months, cut into 6-cm long sections and grown in the dark on moist paper at 23 C to determine if regeneration varies seasonally. New shoots and roots were measured after 8, 11, and 14 days. After 14 days, 69% to 98% of the sections had produced shoots. The mean number of shoots per section was greatest in April (6.4) and least in November (2.0). The monthly mean shoot length ranged from 24 to 43 mm. Although most sections produced shoots, very few produced roots. In May, 31% of the sections grew roots, but only 2% to 16% had new root growth in the other months. For the test period, 83% of the sections produced shoots and only 10% produced roots.
Benzoylprop Ethyl and Its Analogue for the Control of Wild Oat in Wheat
Authors: Kirkland K. J. , Ashford R.
Published: May 2019

Benzoylprop ethyl [Ethyl N-benzoyl-N (3,4-dichlorophenyl)-2-amino-propionate] and WL 29761 [methyl-N-benzoyl-N-(3-chloro-4-fluorophenyl)-2-amino-propionate] were applied to wild oat (Avena fatua L.) in wheat (Triticum aestivum L. ‘Manitou’) to study the yield benefits occurring and the efficacy of the compounds on wild oat. Even though removal of the wild oat was at the later growth stages, benzoylprop ethyl and WL 29761 did produce significant yield increases at both rates tested. Efficacy on wild oat ranged from mediocre to virtually complete control. Crop tolerance was satisfactory throughout the study.
Crop Response and Arsenic Uptake Following Soil Incorporation of MSMA
Authors: Baker R. S. , Barrentine W. L. , Bowman D. H. , Hawthorne W. L. , Pettiet J. V.
Published: May 2019

Five crops were grown for three seasons following a single soil-incorporated application of MSMA (monosodium methanearsonate). Crop sensitivity to soil arsenic decreased as follows: snap beans (Phaseolus vulgarisL. ‘Early Gallatin’ and ‘Tenderette’); rice (Oryza sativaL. ‘Dawn’ and ‘Starbonnet’); soybeans [Glycine max(L.) Merr. ‘Lee 68′]; potatoes (Solarium tuberosumL. ‘Red LaSoda’ and ‘Red Pontiac’); and cotton (Gossypium hirsutumL. ‘Stoneville 7A’). Over the 3-yr period, yield of snap beans was reduced 8, 14, and 85% below the untreated check where MSMA had been incorporated initially at 22, 45, and 269 kg/ha, respectively. Similar reductions in yield of rice were 18, 25, and 55%. Soybean and potato yields were significantly reduced only at the highest rate of MSMA while cotton yields were unaffected. Arsenic content in the edible portion of the crops decreased as follows: rice, snap beans, potatoes, soybeans, and cotton. The arsenic content in crops from the highest MSMA plots seldom exceeded twice that from the untreated plots.
Extraneous Material on Plant Surfaces – An SEM Study
Authors: Davis D. G. , Meola S. M. , Mullins J. S.
Published: May 2019

Leaf surfaces of fifteen plant species contained a large variety of biological and nonbiological structures of various sizes and shapes, which are not a part of the leaf surface but are significant features of all field-grown plants. Some of these structures were fungal hyphae, soil, pollen grains, bacteria, smut teliospores, and many others which could not be identified. This profusion of extraneous material indicates that in-depth studies will have to be made concerning the influence of these materials on agricultural chemicals before the fate of the chemical can be determined with any certainty.
Germination Behavior of Florida Pusley Seeds. II. Effects of Germination-Stimulating Chemicals
Authors: Paul K. B. , Crayton J. L. , Biswas P. K.
Published: May 2019

Freshly harvested seeds of Florida pusley (Richardia scabraL.) require light for germination. Gibberellic acid (GA3) successfully replaced the light requirement of both scarified and unscarified seeds, while cyclic 3′,5′-adenosine monophosphate (C-AMP) stimulated the dark germination of scarified seeds only. Cold-stratification reduced seed germinability. The germination inhibition by cold-stratification was reversed by both GA3and KNO3treatments. Indole-3-acetic acid (IAA), kinetin, thiourea, and acetylcholine (ACh), either had no effect or reduced the germination percentages of Florida pusley seeds under all conditions studied.
The Economics of Common Cocklebur Control in Soybean Production
Authors: Anderson J. M. , McWhorter C. G.
Published: May 2019

The effects of common cocklebur (Xanthium pensylvanicumWallr.) on soybean [Glycine max(L.) Merr.] yields, grades, and net returns were determined by regression analysis of data from 450 research plots from 1971 through 1973. Common cocklebur control from 0 to 100% was achieved by various combinations of preemergence and postemergence practices. Foreign matter in soybean seed samples was 0.7% with total common cocklebur control and 5.1% with no control. At least 70% control of common cocklebur was required to avoid deductions from gross harvested weights due to seed moisture levels exceeding 13%. Small discounts for damaged kernels occurred when common cocklebur control was less than 40%. With 100% common cocklebur control, the estimated US soybean grade was 1.3. Failure to control common cocklebur resulted in a predicted grade of 3.9. When adjusted for various weight discounts, soybean yields were 1170 kg/ha without control of common cocklebur and 1890 kg/ha for 100% control. Soybean yields were increased about 6% for each 10% increase in common cocklebur control. Net returns to land, management, and general farm overhead were $63/ha when common cocklebur was not controlled, and $119/ha with 95% control.
Diquat and Copper-ion Residues in Salmon-spawning Channel
Authors: Yeo R. R. , Dechoretz N.
Published: May 2019

A mixture of diquat [6,7-dihydrodipyrido(1,2-α: 2′,1′-c) pyrazinediium ion] and copper sulfate pentahydrate was applied to artificial chinook salmon (Onchorhynchus tshawytschaWal.) spawning channels to reduce excessive growths of algae [Cladophora glomerata(L.) Kutz]. Juvenile salmon were not harmed by the applications. A concentration of 100 ppb w/w diquat plus 150 ppb copper-ion was maintained for 3 hr. The alga was controlled satisfactorily for distances up to 0.5 km per treatment. Each treatment consisted of one to three applications, each made on consecutive days. Water temperature was 11.2 C during three winter applications and 15.5 C during a spring application. Diquat was rapidly sorbed out of the treated water to 3.8 ppb at 1.6 km. Copper-ion residues dissipated to 60 ppb at 1.6 km.
Fate of Glyphosate in Deciduous Fruit Trees
Authors: Putnam A. R.
Published: May 2019

Glyphosate [N-(phosphonomethyl)glycine] was applied to selected areas on young apple (Malus sylvestrisL.), pear (Pyrus communisL.), sour cherry (Prunus cerasusL.), and peach [Prunus persica(L.) Patsch] trees to observe tree response. Injury occurred only on newly planted peach when contact was made on the basal 12.7 cm of tree trunks. Glyphosate effectively killed suckers without damaging trees. When sprays were applied to a lower branch of apple trees, local injury occurred the same season and the following year, but symptoms were not visible in other portions of the tree. Radiolabeled glyphosate was applied to the basal trunk, leaves, suckers, and fruit of 4-yr-old ‘MacSpur’/MM106 apple and 5-yr-old ‘Bartlett’/seedling pear. Applications on basal trunk areas produced no detectable radioactivity in leaves, buds, or fruits at harvest time. Applications on sucker leaves produced radioactivity only in the treated and adjacent sucker tissue and not in other portions of the tree. The14C-glyphosate moved readily from the treated leaves of lower branches to other leaves, buds, and developing fruit on the same branch but was not detectable in other areas of the tree. After 90 days, 92 to 98% of the extractable radioactivity in leaf, bud, or fruit tissue was unaltered14C-glyphosate.
Effect of Long-Term Atrazine Application on Soil Microbial Activity
Authors: Cole M.A.
Published: May 2019

Analysis of soil in which corn (Zea maysL.) has been grown annually for 9 yr with or without yearly applications of 3.4 kg/ha atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] indicated that long-term atrazine use had little effect upon soil microbes or biochemical processes. With the exception of a transient inhibition of bacterial growth during the first week after field application, repeated applications did not affect the numbers of viable bacteria or fungi, relative abundance of bacteria producing hydrolytic enzymes, or soil enzyme levels.
Tall Morningglory Response to Planting Depth
Authors: Cole A. W.
Published: May 2019

Emergence of tall morningglory [Ipomoea purpurea(L.) Roth] seedlings was delayed and reduced as planting depths increased from 1.3 to 5.0 cm. Development of seedlings emerging from 3.8 cm or greater depth was delayed for up to 4 weeks as indicated by dry weight accumulation. In both greenhouse and field studies, chemical control of tall morningglory was generally greater when seedlings emerged from planting depths of 2.5 cm or greater. The competitive ability of tall morningglory, as indicated by yield reduction of cowpea [Vigna sinensis(L.) Endl], was dependent upon both planting depth and duration of infestation. Cowpea yields were reduced more by the tall morningglory plants that emerged from 1.3 cm than by those that emerged from greater planting depths for a given infestation period.
Effect of pH on Metribuzin Activity in the Soil
Authors: Ladlie James S. , Meggitt William F. , Penner Donald
Published: May 2019

Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] applied preemergence resulted in increased phytotoxicity with increasing soil pH. In the field, fall panicum (Panicum dichotomiflorumMichx.) control, number of dead corn (Zea maysL.) and soybean [Glycine max(L.) Merr.] plants, and crop injury ratings increased, and plant height and grain yield decreased as the soil pH increased. In the greenhouse, corn and soybean grown in soil showed decreased dry weights due to metribuzin as pH increased. By contrast, the pH response to metribuzin was not evident in nutrient-sand culture, indicating that, in soil, pH affected the availability of metribuzin for plant absorption.