bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction in Clostridium difficile infection rates following a multifacility prevention initiative in Orange County, California: A controlled interrupted time series evaluation
Authors: Rizzo Kyle R. , Yi Sarah H. , Garcia Erin P. , Zahn Matt , Epson Erin
Published: May 2019

Objective:

To evaluate the Orange County Clostridium difficile infection (CDI) prevention collaborative’s effect on rates of CDI in acute-care hospitals (ACHs) in Orange County, California.

Design:

Controlled interrupted time series.

Methods:

We convened a CDI prevention collaborative with healthcare facilities in Orange County to reduce CDI incidence in the region. Collaborative participants received onsite infection control and antimicrobial stewardship assessments, interactive learning and discussion sessions, and an interfacility transfer communication improvement initiative during June 2015–June 2016. We used segmented regression to evaluate changes in monthly hospital-onset (HO) and community-onset (CO) CDI rates for ACHs. The baseline period comprised 17 months (January 2014–June 2015) and the follow-up period comprised 28 months (September 2015–December 2017). All 25 Orange County ACHs were included in the CO-CDI model to account for direct and indirect effects of the collaborative. For comparison, we assessed HO-CDI and CO-CDI rates among 27 ACHs in 3 San Francisco Bay Area counties.

Results:

HO-CDI rates in the 15 participating Orange County ACHs decreased 4% per month (incidence rate ratio [IRR], 0.96; 95% CI, 0.95–0.97; P < .0001) during the follow-up period compared with the baseline period and 3% (IRR, 0.97; 95% CI, 0.95–0.99; P = .002) per month compared to the San Francisco Bay Area nonparticipant ACHs. Orange County CO-CDI rates declined 2% per month (IRR, 0.98; 95% CI, 0.96–1.00; P = .03) between the baseline and follow-up periods. This decline was not statistically different from the San Francisco Bay Area ACHs (IRR, 0.97; 95% CI, 0.95–1.00; P = .09).

Conclusions:

Our analysis of ACHs in Orange County provides evidence that coordinated, regional multifacility initiatives can reduce CDI incidence.
Nanoparticle diffusion in sheared cellular blood flow
Authors: Liu Zixiang , Clausen Jonathan R. , Rao Rekha R. , Aidun Cyrus K.
Published: May 2019

Using a multiscale blood flow solver, the complete diffusion tensor of nanoparticles (NPs) in sheared cellular blood flow is calculated over a wide range of shear rate and haematocrit. In the short-time regime, NPs exhibit anomalous dispersive behaviors under high shear and high haematocrit due to the transient elongation and alignment of the red blood cells (RBCs). In the long-time regime, the NP diffusion tensor features high anisotropy. Particularly, there exists a critical shear rate (${\sim}100~\text{s}^{-1}$) around which the shear-rate dependence of the diffusivity tensor changes from linear to nonlinear scale. Above the critical shear rate, the cross-stream diffusivity terms vary sublinearly with shear rate, while the longitudinal term varies superlinearly. The dependence on haematocrit is linear in general except at high shear rates, where a sublinear scale is found for the vorticity term and a quadratic scale for the longitudinal term. Through analysis of the suspension microstructure and numerical experiments, the nonlinear haemorheological dependence of the NP diffusion tensor is attributed to the streamwise elongation and cross-stream contraction of RBCs under high shear, quantified by a capillary number. The RBC size is shown to be the characteristic length scale affecting the RBC-enhanced shear-induced diffusion (RESID), while the NP submicrometre size exhibits negligible influence on the RESID. Based on the observed scaling behaviours, empirical correlations are proposed to bridge the NP diffusion tensor to specific shear rate and haematocrit. The characterized NP diffusion tensor provides a constitutive relation that can lead to more effective continuum models to tackle large-scale NP biotransport applications.
Thermocapillary flow between grooved superhydrophobic surfaces: transverse temperature gradients
Authors: Yariv Ehud , Crowdy Darren
Published: May 2019

We consider the thermocapillary motion of a liquid layer which is bounded between two superhydrophobic surfaces, each made up of a periodic array of highly conducting solid slats, with flat bubbles trapped in the grooves between them. Following the recent analysis of the longitudinal problem (Yariv, J. Fluid Mech., vol. 855, 2018, pp. 574–594), we address here the transverse problem, where the macroscopic temperature gradient that drives the flow is applied perpendicular to the grooves, with the goal of calculating the volumetric flux between the two surfaces. We focus upon the situation where the slats separating the grooves are long relative to the groove-array period, for which case the temperature in the solid portions of the superhydrophobic plane is piecewise uniform. This scenario, which was investigated numerically by Baier et al. (Phys. Rev. E, vol. 82 (3), 2010, 037301), allows for a surprising analogy between the harmonic conjugate of the temperature field in the present problem and the unidirectional velocity in a comparable longitudinal pressure-driven flow problem over an interchanged boundary. The main body of the paper is concerned with the limit of deep channels, where the problem reduces to the calculation of the heat transport and flow about a single surface and the associated ‘slip’ velocity at large distance from that surface. Making use of Lorentz’s reciprocity, we obtain that velocity as a simple quadrature, providing the analogue to the expression obtained by Baier et al. (2010) in the comparable longitudinal problem. The rest of the paper is devoted to the diametric limit of shallow channels, which is analysed using a Hele-Shaw approximation, and the singular limit of small solid fractions, where we find a logarithmic scaling of the flux with the solid fraction. The latter two limits do not commute.
The Ecumenical Intentions of Pope John Paul II. The Third of the Four Quadrennial Lectures Under the Bequest of Judge Paul Dudley, 1750
Authors: Williams George Huntston
Published: May 2019

In his third prescribed lecture out of four, for each of a Harvard student's year in College, Judge Paul Dudley, in parlous times for New England, with the Catholic French and their Indian allies a constant threat, asked that his Lecturer be mindful that the Seer of Revelation, carried away in the Spirit into a wilderness (17:3), saw a woman “and on her forehead was written a name of mystery: Babylon the great, mother of harlots” (17:5). He expressly identified “the Romish Church with that mystical Babylon.” The first Hollis Professor of Divinity, Edward Wigglesworth (1693–1765), gave the initial anti-Popery lecture in 1757, and he more than adequately fulfilled the Donor's intentions.
Criteria for Evaluating Textual Readings: The Limitations of Textual Rules
Authors: Tov Emanuel
Published: May 2019

Old Testament textual criticism focuses on variant readings (such as “on the seventh day” in the MT of Gen 2:2 as opposed to “on the sixth day” in the Samaritan Pentateuch and in the LXX and the Peshitta) and these readings must be evaluated carefully. Ever since the seventeenth century, abstract rules have been formulated for the evaluation of textual readings. These abstract rules are of different types and each generation of OT scholars has a different approach to them. In the seventeenth century only a few such rules were suggested, but after that time one notices a growing appreciation for and employment of textual rules. In the present century one discovers a frequent reliance on–and often a blind belief in–textual rules.
Grace and Works: The Rise and Division of Covenant Divinity in Elizabethan Puritanism
Authors: McGiffert Michael
Published: May 2019

In a handbook of 1607 for students of divinity and lightly learned clergymen, the puritan Richard Bernard gave pride of place to the works of continental theologians. For the best catechisms he cited Calvin and Ursinus; for “the definitions and distributions of the principal heads of theology,” Polanus; for commonplaces, Musculus, Martyr, and Szegedinus; for commentaries, Calvin, Martyr, and Musculus. These writers had each contributed to the systematizing of covenant exegesis and doctrine (though Bernard did not pick them for that reason), and it was no accident that this naming of great names did not include a single Englishman.
Common Waterplantain (Alisma triviale) Interference with Wild Rice (Zizania palustris)
Authors: Ransom J. K. , Oelke E. A.
Published: May 2019

Three cultivars of wild rice (Zizania palustrisL.) were grown with various densities of common waterplantain (Alisma trivialePursh) established from seeds and from rootstocks during 1979 and 1980. Wild rice cultivars did not differ in their response to common waterplantain interference. Common waterplantain grown from seeds at densities up to 82/m2did not significantly reduce wild rice yield. Common waterplantain established from rootstocks significantly reduced wild rice yield at densities as low as 3/m2. A density of 43/m2reduced wild rice yield by 91%. The yield component most susceptible to interference from common waterplantain was panicles per plant. The number of seeds per panicle was reduced by densities as low as 11/m2and seed weight was reduced by densities of 22/m2or greater. Only a density of 43/m2reduced the stand of wild rice. Common waterplantain established from rootstocks at a density of 17 plants/m2did not reduce wild rice yield if removed by 7 weeks after planting. Interference from common waterplantain for 9 weeks or longer reduced wild rice yield by approximately 50%.
Selection of Sampling Methods to Determine Weed Abundance in Apple (Malus domestica) Orchards
Authors: Conn Jeffery S. , Proctor Charles H. , Skroch Walter A.
Published: May 2019

A method is presented to determine which of a set of sampling techniques is most nearly optimum for sampling weed abundance. To employ the method, one needs first to develop a set of sampling alternatives. A pilot survey is then conducted to determine time costs and sampling and measurement error variances associated with each technique. We used this method to determine which of three plot sizes (0.6 by 0.6 m, 0.6 by 1.5 m, 1.2 by 2.1 m) and two types of orchard scans is most nearly optimum for estimating weed abundance in apple [Malus domestica (Bork)] orchards. The results indicate that, for weed species that are fairly apparent, orchard scans are optimal when less than 8 h of sampling effort is expended, but when a high degree of precision is required, or when the weed species is more difficult to detect, plot samples may be the better choice. A size of plot ca. 0.6 by 1.5 m size was found to be most nearly optimum.
Frequency of Herbicide Treatments for Summer and Winter Weed Control in Turfgrasses
Authors: Johnson B. J.
Published: May 2019

Four herbicides were applied in the spring and fall over a 3-yr period to Kentucky bluegrass [Poa pratensis (L.) ‘Common′] in the Mountain Region and bermudagrass [Cynodon dactylon (L.) Pers. ‘Common′] in the Piedmont Region of Georgia at different frequencies of treatments for summer and winter weed control. Large crabgrass [Digitaria sanguinalis (L.) Scop.] was controlled throughout the 3-yr period from spring treatments of bensulide [O,O-diisopropyl phosphorodithioate S-ester with N-(2-mercaptoethyl)benzenesulfonamide] at 11.2 kg/ha and oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-δ2-1,3,4-oxadiazolin-5-one] at 4.5 kg/ha in the first year followed by 5.6 kg/ha for bensulide and 2.3 kg/ha for oxadiazon the following 2 yr. To control large crabgrass with benefin (N- butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine) it was necessary to apply 3.4 kg/ha for 2 consecutive yr before rates could be reduced to 1.7 kg/ha. Oxadiazon was the only herbicide that controlled goosegrass [Eleusine indica (L.) Gaertn.] completely. Control was excellent throughout the 3-yr period when oxadiazon was applied at full rate in the spring of the first year with no additional treatments during the following 2 yr. Optimum control of winter weeds was obtained throughout the 3-yr period when herbicides were applied at full rates for the spring and fall treatments the first year followed by one-half rates at similar dates the following 2 yr. Bensulide treatments increased cover of corn speedwell (Veronica arvensis L.) and hop clover (Trifolium agrarium L.); DCPA (dimethyl tetrachloroterephthalate) and benefin increased spur weed (Soliva spp.) and wild parsnip (Pastinaca sativa L.); and oxadiazon increased wild parsnip and thymeleaf sandwort (Arenaria serpyllifolia L.).
Effects of Variations in Drop Makeup on the Phytotoxicity of Glyphosate
Authors: Ambach Rolfe M. , Ashford Ross
Published: May 2019

Field and greenhouse trials have shown that ultra-low-volume applications (ULV) of glyphosate (N-(phosphonomethyl)glycine] exhibit a greater phytotoxic effect on barley (Hordeum vulgareL. ‘Bonanza′) at a given rate than do high-diluent-volume applications with a conventional hydraulic sprayer. Three greenhouse studies and one field trial were conducted to evaluate the influence of individual drop makeup on the effectiveness of ULV applications. Barley plants were treated at the four-leaf stage with one, three, or nine drops (1μl each) of glyphosate and a non-ionic surfactant with the concentration of the drops adjusted so that the total amount of active ingredient applied to each plant was constant. Application of a single, concentrated drop was significantly more effective in reducing total shoot growth than were applications of more dilute drops in greater number. When the dilute drop was supplemented with additional surfactant, phytotoxicity was restored, provided there was a sufficiently high concentration of glyphosate in the drop. With the substitution of a commercial formulation of glyphosate, the response of barley to variations in drop number and drop concentrations followed a similar trend. The response of field-grown plants did not differ from plants grown under controlled conditions.
Germination and Growth of Grasses and Legumes from Seeds Treated with Glyphosate and Paraquat
Authors: Salazar Luis C. , Appleby Arnold P.
Published: May 2019

In greenhouse studies, glyphosate [N-(phosphonomethyl)glycine] at 1.0 and 3.0 kg/ha and paraquat (1,1′-dimethyl-4,4-bipyridinium ion) at 0.6 kg/ha were applied to exposed seeds of six grasses and two legume species on continuously wet soil. Glyphosate reduced germination of both legumes and three grasses and reduced seedling growth of all species. Paraquat was toxic only to the grasses. Glyphosate mainly affected germination and growth of legumes when applied directly to their seeds. Reductions also were measured, however, when untreated legume seeds were transferred to glyphosate-treated soil.
Effects of Shade on Silverleaf Nightshade (Solanum elaeagnifolium)
Authors: Boyd John W. , Murray Don S.
Published: May 2019

Plants started with seed, 'seedlings', and established plants of silverleaf nightshade (Solanum elaeagnifoliumCav.) were grown in the field under shade levels of 0, 47, 63, and 92% of full sunlight to determine vegetative, reproductive, and physiological responses to shade. Dry-matter production of both 'seedling’ and established plants declined markedly with increasing shade levels. Established plants did not bear fruit under 92% shade, and 63% shade prevented fruit production by 'seedlings'. Taproots of plants grown in full sunlight contained 16% more total non-structural carbohydrate (TNC) per gram dry weight than taproots of plants grown under 92% shade. Leaves of established plants grown under moderate shade had significantly more chlorophyll per unit leaf fresh weight than plants grown in full sunlight; however, plants under heavy (92%) shade had 35% less chlorophyll per unit leaf area than unshaded plants. The chlorophylla/bratio of the 92%-shaded plants was significantly less than with other treatments. Leaf area increased, with increasing shade; however, leaf weight per unit area decreased because of thinner leaves. Photosynthetic rates of recently expanded leaves were 10.4, 4.6, 3.3, and 0.9 mg CO2· dm−2· h−1for the 0, 47, 63, and 92% shade treatments, respectively.
Genetic Analysis of Chloroplast Atrazine Resistance in Brassica campestris – Cytoplasmic Inheritance
Authors: Machado V. Souza , Bandeen J. D.
Published: May 2019

Analysis of reciprocal F1, F2, F3, and backcross progeny from crosses between atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine]-resistant and several susceptible genotypes of Brassica campestris L. indicated that triazine resistance was inherited cytoplasmically from the female parent. A partially dominant chlorotic cotyledon was used as a genetic marker to confirm true hybrids in the reciprocal F1 progenies. Phytotoxicity of atrazine was correlated with loss of the Hill reaction.
Germination and Establishment of Prostrate Spurge (Euphorbia supina)
Authors: Krueger Robert R. , Shaner Dale L.
Published: May 2019

Germination of prostrate spurge (Euphorbia supinaRaf.) seeds collected in August, September, October, and November 1977 at Riverside, California was 53, 30, 18, and 16%, respectively. Stratification of seeds collected in August, September, and October at 5 C for 3 weeks or more increased germination to 70 to 80%. Prostrate spurge seeds germinated at constant temperatures of 20 to 40 C, with optimum temperatures of 25 to 30 C. Maximum germination occurred under alternating temperatures with a high temperature of 30 to 35 C and a low temperature of 15 to 25 C. Germination in the dark was much lower than in the light. Seedling establishment of seeds collected in August sown at 0.0- to 0.5-cm depths was 30 to 35%, but establishment from 2 cm declined to near 0%. Light intensity did not affect the number of seedlings established, but the seedlings established were larger under higher light intensities.
Control of Five Broadleaf Weeds in Sugarbeets (Beta vulgaris) with Glyphosate
Authors: Schweizer Edward E. , Bridge Larry D.
Published: May 2019

Field experiments were conducted to study the feasibility of applying glyphosate [N-(phosphonomethyl) glycine] postemergence with a recirculating sprayer and a vertical roller for the control of common lambsquarters (Chenopodium albumL.), common sunflower (Helianthus annuusL.), kochia [Kochia scoparia(L.) Schrad.], redroot pigweed (Amaranthus retroflexusL.), and velvetleaf (Abutilon theophrastiMedic.) in sugarbeets (Beta vulgarisL.). Glyphosate was applied twice each year at 1.7 kg/ha with a recirculating sprayer in 1977 and 1978, or twice as a 20% (v/v) solution with a vertical-roller applicator in 1979. By harvest, 70 to 74% of the total population of treated common sunflower, kochia, and redroot pigweed, 61% of the common lambsquarters, and 30% of the velvetleaf was dead. Root yields in glyphosate-treated plots, when averaged over 3 yr, were increased 5800, 8500, 12 500, and 13400 kg/ha at densities of 6, 12, 18, and 24 broadleaf weeds (equal densities of common lambsquarters, kochia, and redroot pigweed)/30m of row, respectively. Where equal densities of common sunflower and velvetleaf competed with sugarbeets, root yields in glyphosate-treated plots, when averaged over 2 yr, were increased 4400, 11900, 11700, and 10700 kg/ha, respectively, at these same densities.
Enhanced Phytotoxicity of Bentazon with Organophosphate and Carbamate Insecticides
Authors: Campbell James R. , Penner Donald
Published: May 2019

The organophosphate insecticides, malathion [S-1,2-di (ethoxycarbonyl)ethylO, O-dimethyl phosphorodithioate], parathion (O, O-diethylO-4-nitrophenyl phosphorothioate) and diazinon (O,O-diethylO-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate) combined with bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide], caused severe injury to soybean [Glycine max(L.) Merr. ‘Corsoy′] and navy bean (Phaseolus vulgarisL. 'Seafarer′). Postemergence tank – mixture applications of bentazon with organophosphate or carbamate insecticides, or soil-applied organophosphate insecticides prior to bentazon treatments, did not interact with bentazon to injure corn (Zea maysL. ‘Great Lakes Hybrid 4122′). Technical grade malathion interacted with bentazon to the same extent as formulated malathion. Combination treatments of malathion with bentazon resulted in the same degree of injury whether they were applied as tank mixtures or split applications 48 h apart.
Weed Control in Cowpea (Vigna unguiculata) in the Humid Tropics
Authors: Akobundu I. Okezie
Published: May 2019

At least two weedings within the first 5 weeks after sowing are necessary to minimize yield reduction caused by weeds in cowpea [Vigna unguiculata(L.) Walp.]. During a 3-yr study, a preemergence application of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] at 2.0 to 3.0 kg/ha, DCPA (dimethyl tetrachloroterephthalate) at 10.0 kg/ha, or pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] at 2.0 or 2.5 kg/ha controlled most annual grasses effectively. Itchgrass (Rottboellia exaltataL.) was controlled with pendimethalin at 2.5 kg/ha, but metolachlor had no effect on this weed. These herbicides caused no crop injury and cowpea grain yield was as good as in the handweeded and weed-free plots. Alachlor [2-chloro-2′, 6′-diethyl-N-(methoxymethyl) acetanilide] applied preemergence at 2.0 kg/ha was effective against annual weeds, but was phytotoxic to cowpea.
Comparisons of Sites Infested and Not Infested with Saltcedar (Tamarix pentandra) and Russian Olive (Elaeagnus angustifolia)
Authors: Carman John G. , Brotherson Jack D.
Published: May 2019

Saltcedar (Tamarix pentandra Pall.) and Russian olive (Elaeagnus angustifolia L.) invade moist pastures and rangeland and cause serious forage-production and soil-water losses. Our objective was to develop criteria for classifying sites relative to the likelihood of infestation by saltcedar and Russian olive, based on comparisons of soil and vegetation characteristics of infested and adjacent uninfested sites. Discriminant analyses indicated that Russian olive occurs on soils with low to medium concentrations of soluble salts (100–3500 ppm), whereas saltcedar occurs on soils with much higher soluble salt concentrations (700–15000 ppm). Characteristics of the herbaceous vegetation on sites infested with saltcedar or Russian olive differed distinctly from each other and from adjacent, uninfested sites. Frequency of occurrence of certain herbaceous understory species provided the most accurate basis for discrimination of infested and uninfested areas. Discriminant analysis may be of value in the development of infestation-proneness indices.
Metolachlor and Alachlor Effects on Membrane Permeability and Lipid Synthesis
Authors: Mellis Jill M. , Pillai Parthan , Davis Donald E. , Truelove Bryan
Published: May 2019

Metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] at 1 × 10−5and 1 × 10−4M increased the leakage of previously absorbed,32P-labeled orthophosphate from the roots of onion (Allium cepaL.), a susceptible species, by 14 and 41 times the control values, respectively. A significant amount of32P leaked from the roots of the moderately susceptible species, cotton (Gossypium hirsutumL. ‘DPL 61′) and cucumber (Cucumis sativusL. ‘Ashley′), whereas no significant loss of32P occurred from two tolerant species, soybean [Glycine max(L.) Merr. ‘Bragg′] and corn (Zea maysL. ‘Pioneer 3369A′). At either 1 × 10−7or 1 × 10−6M, 1,8-naphthalic anhydride (NA) prevented32P leakage from onion roots in the presence of 1 × 10−5M metolachlor. High concentrations of NA [0.1% (w/v) suspensions], however, promoted32P leakage and did not protect onion roots from the leakage induced by high concentrations (1 × 10−4M) of metolachlor. Neither metolachlor nor alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], at 1 × 10−4M, inhibited the uptake of acetate-2-14C or malonic acid-2-14C into excised cotton root tips or the incorporation of the precursors into lipids. Similarly, neither herbicide inhibited phospholipid synthesis by cotton root tips. Incorporation of14C-choline chloride into phosphatidylcholine was not significantly inhibited by metolachlor.
Quadratic Response Surface Analysis of Seed-Germination Trials
Authors: Evans Raymond A. , Easi Debra A. , Book Don N. , Young James A.
Published: May 2019

Quadratic response surface analysis was applied to data of seed germination in relation to temperature. Analysis of these data is the comparing of several levels of quantitative factors. In such situations, multiple-comparison procedures, such as Duncan's multiple range test, are inappropriate. The data were the germination percentages of four species at 55 constant or alternating day and night temperature regimes. A quadratic response surface was developed for each species using multiple-regression techniques. Estimated germination values and their confidence limits were derived from the quadratic response surface of each species for each cold-period temperature through a series of warm-period temperatures. Many parameters were synthesized from the response surfaces to evaluate germination of the four species in relation to temperature. These comparisons form a statistically valid basis from which to select the most adapted plant species and predict the best time for planting or applying weed-control treatments.
Addition of R-33865 to EPTC for Extended Herbicide Activity
Authors: Obrigawitch Tim , Roeth Fred W. , Martin Alex R. , Wilson Robert G.
Published: May 2019

Laboratory and field studies were conducted to examine the influence of R-33865 (O, O-diethyl-O-phenol phosphorothioate) on the degradation rate of EPTC (S-ethyl dipropylthiocarbamate) in three soils that had a history of repeated EPTC application and exhibited accelerated degradation of EPTC. In field studies, addition of R-33865 to EPTC extended EPTC persistence in soil and provided increased shattercane [Sorghum bicolor(L.) Moench] control. In two soils that exhibited rapid EPTC degradation, addition of R-33865 to EPTC extended the half-life of EPTC from 9 to 18 days and from 6 to 15 days, respectively. Evolution of14CO2from14C-carbonyl EPTC-treated soils with a prior history of EPTC treatment was significantly reduced when R-33865 was added; however, the initial lag period of EPTC degradation was not restored. Addition of R-33865 to EPTC on soils with no prior EPTC treatment did not extend persistence of EPTC in soil.
Some Fundamental Characteristics of Quality Research
Authors: Davis Donald E.
Published: May 2019

“We're Number 1” has become an oft-repeated claim in sports, but agricultural research in the United States must admit to being only a poor Number 2 (9). The Soviet Union exceeds the United States 3.4 to 2.2 in percent of gross national product invested in agricultural research, 60000 to 12000 in numbers of agricultural scientists, and 150000 to 13000 in support personnel (9). Furthermore, agricultural scientists hold eminent positions in the Soviet Union and are regularly admitted to the Soviet Academy of Science, whereas few United States agriculturists are elected to the United States National Academy of Sciences. This disparity is hard to understand in view of the importance of agriculture in the United States. For example, it is anticipated that in 1982 the United States will pay $60 billion for imported oil and that two-thirds of this will be paid for by agricultural exports (6). According to Schultz (8) in his address on socio-economic aspects of agriculture, “the future food supply is dependent in large measure on achievements in agricultural research”. It would appear that accepting second place to the Soviet Union in agricultural research is even more unacceptable than second place in space. This audience does not need to be convinced of the importance of agricultural research. We might, however, profit by enumerating some of the characteristics of a high quality research program. The comments I am going to make are not intended to be all inclusive and are primarily based on my observations of agricultural research in land-grant universities. Most of the comments are, however, equally applicable to other fields of research and to other agencies.
Impact of Weed Science and Agricultural Chemicals on Farm Productivity in the 1980's
Authors: Hill Gideon D.
Published: May 2019

We are meeting near the Boston Common, an historic 50-acre public park that was set aside in 1630 for “common use as a cow pasture and training field.” Records show that 100 people (pirates, Indians, Quakers, and suspected witches) were hanged on the Common by the early Puritans who established the Massachusetts colony.

There were no farmers or scientists on this list. Hopefully, after this presentation, my name will not be added to the Puritans' “hit” list.
Compatibility of Diclofop and BAS 9052 with Bentazon
Authors: Campbell James R. , Penner Donald
Published: May 2019

BAS 9052 {2-[1-(ethoxyimino)-butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} effectively controlled annual grasses in soybean [Glycine max(L.) Merr.] alone or in combination with bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] in greenhouse and field experiments. The activity of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} on annual grasses was reduced if combined with bentazon in a tank mixture. The wettable powder formulation of bentazon, as well as a day temperature of 30 C, slightly reduced the antagonistic interaction from that of the emulsifiable concentrate formulation of bentazon or a day temperature of 15 C. In greenhouse studies ‘Corsoy’ soybean plants were injured by the diclofop-bentazon combination. In field studies, however, the injury was not sufficient to reduce grain yields.
Some Metabolic Responses ofRhizoctonia solanito Napropamide
Authors: Kurtz Mark E. , Cole A. Wayne , Salin Marvin L.
Published: May 2019

Responses ofRhizoctonia solaniKuhn to napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide], were evaluated by measuring whole-cell respiration, mitochondrial respiration, ATP synthesis, and membrane leakage. Whole-cell respiration, measured with an O2electrode, was stimulated in the presence of napropamide at 1.1, 2.2, and 4.4 × 10−5M. Mitochondrial respiration was stimulated at 1.1 × 10−11M, but higher concentrations were inhibitory. The addition of 10−5M napropamide to isolated mitochondria ofR. solaniresulted in reduced ATP synthesis, measured by the firefly luciferase assay, and in increased membrane permeability as measured by increases in electrical conductivity of filtrates fromR. solanigrown in culture medium containing napropamide. These results indicate that, under laboratory conditions, napropamide reduced ATP synthesis, caused membrane leakage, and stimulated respiration inR. solani.
Ethalfluralin Activity in Cucumber (Cucumis sativus)
Authors: Derr Jeffrey F. , Monaco Thomas J.
Published: May 2019

In greenhouse studies, soil organic matter reduced the herbicidal activity of ethalfluralin (N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)benzenamine). Fifty percent inhibition (I5.0) values for barnyardgrass [Echinochloa crus-galli(L.) Beauv.] stand, injury, and shoot fresh weight increased as the soil organic-matter level increased. No difference in ethalfluralin tolerance was found among 16 cucumber (Cucumis sativusL.) cultivars. When grouped according to market type, fresh market cultivars tended to be injured more than pickling cultivars by excess ethalfluralin. Both shoots and roots of cucumber absorbed the herbicide, but exposure of roots to ethalfluralin was more toxic than exposure of shoots. Field studies indicated that with certain edaphic and environmental conditions, cucumbers can be injured by preemergence applications of ethalfluralin. Injury was greatest in a low organic-matter soil following a heavy rain. Ethalfluralin at 1.3 kg/ha gave adequate weed control in 1 and 3% organic-matter soils, but not in a 9% organic-matter soil.
Influence of Herbicides on Direct-Seeding Establishment of Birdsfoot Trefoil (Lotus corniculatus) into Grass Sods
Authors: Linscott Dean L. , Vaughan Richard H.
Published: May 2019

Birdsfoot trefoil (Lotus corniculatusL.) was direct-seeded into five different grass sods after treatment with dalapon (2,2-dichloropropionic acid), glyphosate [N-(phosphonomethyl)glycine], or paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) at varying rates for vegetation control. During establishment, the stands of birdsfoot trefoil were acceptable in all treated- and untreated-sod grass sods except 1 yr in untreated tall fescue (Festuca arundinaceaSchreb.) and timothy (Phleum pratensisL.) and 1 yr in tall fescue receiving 3 kg/ha of dalapon. Herbicide treatments resulted in a more rapid development of a significant legume component in the sward and an increase in forage yield over the untreated plots. Minimum herbicide application rates for best return for grass sod control were 0.5, 1, and 5 kg/ha respectively for paraquat, glyphosate, and dalapon.
Noncompetitive Effects of Johnsongrass (Sorghum halepense) on Soybeans (Glycine max)
Authors: Lolas Petros C. , Coble Harold D.
Published: May 2019

Studies were conducted in North Carolina to determine if johnsongrass [Sorghum halepense(L.) Pers.] rhizomes in the soil exude or produce substances that can affect soybean [Glycine max(L.) Merr.] seedling growth. Fresh and dry weights of soybean seedlings were dependent on the concentration of rhizomes present in the soil before soil samples were used for soybean growth, and on the time of year when soil samples were collected. In studies on rhizome residues, soybean seedling dry weight decreased as percent of dry, decayed rhizomes in the soil increased. For each rhizome concentration, soybean growth inhibition decreased as decay time increased. Fresh and dry weights of soybean plants were reduced by diluted fresh rhizome extract used for irrigation once a week for 3 weeks. Since no rhizomes were present in most of the soils during soybean growth and since nutrient concentrations, organic matter, and pH were not different among the soils used, it is suggested that johnsongrass rhizomes living or decaying in the soil exude, contain, or produce substances that exhibit allelopathic characteristics to soybean growth.
Influence of Quackgrass (Agropyron repens) Density and Duration of Interference on Soybeans (Glycine max)
Authors: Young Frank L. , Wyse Donald L. , Jones Robert J.
Published: May 2019

The effect of quackgrass [Agropyron repens(L.) Beauv.] density and duration of interference on soybeans [Glycine max(L.) Merr.] was investigated in two studies. In the density study, the average reduction in soybean yield by quackgrass densities of 520 and 910 shoots/m2was 19 and 55%, respectively. Quackgrass densities of 95 and 160 shoots/m2did not significantly reduce soybean yields. The number of branches that produced pods, the number of pods and seeds per plant, and soybean height were reduced by the two highest densities. In 1980, quackgrass densities of 265 and 595 shoots/m2reduced soybean leaf area and plant dry weight. Leaf area partitioning (LAP), leaf weight partitioning (LWP), and net assimilation rate (NAR) of soybeans were reduced by a quackgrass density of 595 shoots/m2. In the duration study, interference by a natural stand of quackgrass for 6 weeks, 8 weeks, and full-season decreased soybean yield an average of 11, 23, and 33%, respectively. Results from the duration study suggest that a selective postemergence herbicide for the control of quackgrass in soybeans would be beneficial if available.
Behavior of BAS-9052 OH in Soybean (Glycine max) and Johnsongrass (Sorghum halepense) Plant and Cell Cultures
Authors: Swisher Beth A. , Corbin Frederick T.
Published: May 2019

Research involved the behavior of BAS-9052 OH {2[1-(ethoxyimino)butyl]-5-[2(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} in soybean [Glycine max(L.) Merr.] and johnsongrass [Sorghum halepense(L.) Pers.] plants, and the fate of14C-BAS-9052 OH in intact plants and cell cultures of both species. Microscopic examination of seedling johnsongrass plants (two- to three-leaf stage) treated with foliar applications of 0.48 μg/plant revealed disorganized apical regions and necrotic cells within the apex and leaf primordia of the shoot. Necrotic zones were also evident at the base of expanding leaves and in root apices 1 day after treatment. Following application of14C-BAS-9052 OH, the same radioactive products were isolated from cell cultures and intact plants. Products included BAS-9052 OH and three unidentified metabolites. Greater proportions of unchanged BAS-9052 OH were extracted from the apical leaves, roots, and cell cultures of johnsongrass than of soybean. BAS-9052 OH was thermal and photo-labile, and a large portion of14C may not have entered the plant as BAS-9052 OH. However, tolerant soybean plants and cell cultures appeared to have metabolized the herbicide more rapidly than susceptible johnsongrass plants and cell cultures. An average of 64% of the14C remained in the treated leaf of johnsongrass compared with 48% in soybean. About one-half as much14C was translocated to the apical leaves of susceptible johnsongrass than tolerant soybean. Therefore, differential uptake and translocation cannot account for the selectivity of BAS-9052 OH.
Response of False Broomweed (Ericameria austrotexana) and Associated Herbaceous Vegetation to Pelleted Herbicides
Authors: Mayeux H. S. , Chamrad A. D.
Published: May 2019

Aerial applications of pelleted tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N, N′-dimethylurea} at 1 kg/ha to rangeland reduced canopy cover of the subshrub false broomweed (Ericameria austrotexanaM.C. Johnst.) by 69 to 78%. Complete control was obtained with 2 kg/ha of tebuthiuron. Picloram (4-amino-3,5,6-trichloropicolinic acid) pellets applied at 2 kg/ha controlled false broomweed in two of four experiments; effectiveness of soil-applied picloram appeared to depend upon sufficient rainfall to move the herbicide into the soil soon after treatment. After the first growing season following application, density of herbaceous species tended to be higher in plots receiving either herbicide than in untreated plots. Picloram suppressed curlymesquite [Hilaria berlangeri(Steud.) Nash], but had little effect on other components of the herbaceous vegetation. Abundance of curlymesquite increased substantially following applications of tebuthiuron, at the expense of annual and short-lived perennial grasses and herbaceous broadleaf species.
Effects of Shading and Temperature on Showy Crotalaria (Crotalaria spectabilis)
Authors: Patterson David T.
Published: May 2019

Showy crotalaria (Crotalaria spectabilisRoth) was grown in a controlled-environment greenhouse with a day/night temperature of 32/26C at full sunlight and under 40, 60, or 90% shade. Shading significantly reduced height, dry-matter accumulation, leaf production, leaf-area expansion, axillary-branch development, reproductive development, and the partitioning of plant biomass into stems. Shading increased the partitioning of plant biomass into leaves and the leaf area ratio. Constant shading or shading from 0 through 25 days after planting reduced the leaf area duration (LAD) proportionally more than the net assimilation rate (NAR). Shading from 25 to 67 days after planting reduced NAR and LAD equally. In other experiments reducing the day/night temperature below 32/26C significantly reduced plant height, leaf area, and the rate of leaf production. Dry-matter production decreased significantly at temperatures below 29/23C, because of substantial reduction in LAD. Showy crotalaria flowered and produced seed at temperatures ranging from 23/17C to 32/26C. The results indicate that the geographical distribution of showy crotalaria in the United States probably will continue to increase.
Controlling Volunteer Corn (Zea mays) in Soybeans (Glycine max) with Diclofop and Glyphosate
Authors: Andersen Robert N. , Ford J. Harlan , Lueschen William E.
Published: May 2019

We compared diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid}, as an early over-the-top spray treatment, and glyphosate [N-(phosphonomethyl)glycine], applied twice in repeated applications with a rope-wick applicator, for control of simulated volunteer corn (Zea maysL.) planted in clumps at various intervals in rows of soybeans [Glycine max(L.) Merr.]. Uncontrolled corn at the lowest density (clumps 2.4m apart in the row) reduced soybean yields an average of 31%. Both herbicides were highly effective in controlling corn, but when corn densities were high, diclofop treatments often resulted in greater soybean yields than did glyphosate treatments — presumably because corn interfered with the soybeans for a longer time before glyphosate was applied.
Effect of a Weevil,Rhinocyllus conicus, on Musk Thistle (Carduus thoermeri) Seed Production
Authors: McCarty Melvin K. , Lamp William O.
Published: May 2019

Three musk thistle (Carduus thoermeriWeinm.) sites that were infested with a weevil (Rhinocyllus conicusFroel.) and a fourth non-infested site were evaluated for numbers of insects and seeds per seed head. At four successive weekly intervals, seed heads were sampled just after flowering. Initial sampling was in 1978 and was repeated in 1979. Weevil incidence in heads blooming during the first week was 6.7/head in 1978 and 28.0 in 1979. At infested sites, production of fully developed seeds averaged 28% less than at the non-infested site in 1978 and 78% less in 1979. Heads that were in bloom during the fourth sampling week had an infestation rate less than one weevil/head in both years. Fully developed seeds germinated well (96 to 99%) and were not affected by date of bloom. Because many heads bloomed during the third and fourth weeks, a large number of viable seeds were still produced at infested sites.
Soil Persistence of Tebuthiuron in the Claypan Resource Area of Texas
Authors: Bovey Rodney W. , Meyer Robert E. , Hein Hugo
Published: May 2019

Pelleted tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl] -N,N′-dimethylurea} was applied aerially on duplicate plots at 2.2 and 4.4 kg/ha in spring, summer, fall, and winter of 1978 and 1979. Treatments were made near Bryan in the Claypan Resource Area of Texas on an area supporting a stand of mixed brush consisting mostly of oak (Quercus) species. Soils were sampled at eight locations in each plot at depths of 0 to 15 and 15 to 30 cm in March 1980. Bioassays using ‘Tamcot’ cotton (Gossypium hirsutumL.) and ‘Caddo’ wheat (Triticum aestivumL.) were done in the greenhouse to detect levels of tebuthiuron residues in the soil. A standard curve was developed to compare known concentrations of tebuthiuron to the unknown content from treated plots. Tebuthiuron persisted in all treated soils and ranged from 0.08 to 0.49 μg/g. Concentrations were usually greater in soil treated in 1979 than in 1978 and in soil treated with 4.4 kg/ha of tebuthiuron than 2.2 kg/ha. No consistent differences in tebuthiuron residues existed either between soil depths or among seasons of application using the bioassay.
Root Distribution and Reproductive Biology of Honeyvine Milkweed (Cynanchum laeve)
Authors: Soteres John K. , Murray Don S.
Published: May 2019

Laboratory and field experiments were conducted to describe the root system of honeyvine milkweed [Cynanchum laeve(Michx.) Pers.], and to study factors affecting the growth of plants from root fragments of shallow, ascending roots. The root system of a typical plant was composed of lateral roots radiating from a sparsely-branched, vertical taproot. Laterals tended to concentrate in a boundary area between a loamy surface soil and a zone of clay accumulation, this boundary area being below the zone of cultivation. Vertical taproots were found to a depth of 2 m, with sections collected at this and shallower depths demonstrating the ability to produce aerial shoots. In laboratory studies, root sections were killed either by freezing for 2 h or by drying at either 20 or 30 C for 24 h. The optimum temperature for shoot development from root sections was between 20 and 30 C. Shoot emergence and growth from buried root sections were generally unaffected by either depth of planting or root length. As many as 45 daughter shoots were produced from a single plant originating from seed, and 27 daughter shoots were developed from a root section 131 days after planting. The maximum distance daughter shoots were observed from original plants 131 days after planting was 111 cm.
The Basis for Selectivity of Root-Applied Ethofumesate in Sugarbeet (Beta vulgaris) and Three Weed Species
Authors: Duncan David N. , Meggitt William F. , Penner Donald
Published: May 2019

The absorption, translocation, and metabolism of 14C-ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] in sugarbeet (Beta vulgaris L.), common ragweed (Ambrosia artemisiifolia L.), redroot pigweed (Amaranthus retroflexus L.), and common lambsquarters (Chenopodium album L.) were studied as possible bases for selectivity of preemergence-applied ethofumesate. The sensitive redroot pigweed and common lambsquarters plants translocated more 14C-ethofumesate from nutrient culture to the leaf tissue than did the tolerant sugarbeet and common ragweed. The radioactivity was more highly concentrated in sugarbeet and common ragweed roots. The rapid metabolism of ethofumesate by sugarbeet and common ragweed, particularly that which accumulated in the leaf tissue, appeared related to tolerance.
Basis for Increased Activity from Herbicide Combinations with Ethofumesate Applied on Sugarbeet (Beta vulgaris)
Authors: Duncan David N. , Meggitt William F. , Penner Donald
Published: May 2019

Differences in susceptibility of sugarbeet (Beta vulgarisL.) to preemergence application of ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate], pyrazon [5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone], and TCA (trichloroacetic acid) were evaluated in several combination treatments. Exposure of plants to ethofumesate severely decreased epicuticular wax deposition on leaf surfaces. Separation of epicuticular wax into major components by gas-liquid chromatography indicated that ethofumesate decreased deposition of alkanes andsec-ketones, but increased the percentage of long-chain waxy esters. TCA also decreased deposition of alkane and ketone components, but not of waxy esters. Waxes were unaffected by pyrazon. Greater foliar absorption of14C-ethofumesate,14C-desmedipham [ethylm-hydroxycarbanilate carbanilate (ester)], and14C-ethofumesate +14C-desmedipham was observed in plants that received preemergence treatments of ethofumesate plus TCA compared to pyrazon or a control.
Common Dandelion (Taraxacum officinale) Control in Alfalfa (Medicago sativa)
Authors: Sheaffer C. C. , Wyse D. L.
Published: May 2019

Field experiments were conducted at four locations to evaluate the efficacy of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], simazine [2-chloro-4,6-bis(ethylamino)-s-triazine], buthidazole {3[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone} and 2,4-DB [4-(2,4-dichlorophenoxy) butryic acid] treatments for common dandelion (Taraxacum officinaleWeber) control in established alfalfa (Medicago sativaL.). Most herbicides temporarily reduced common dandelion populations at all locations, but by the end of the first year only buthidazole reduced them on fine-textured soils, but buthidazole, metribuzin and fall-applied simazine reduced populations on coarse-textured soils. Only buthidazole controlled common dandelion in the year following application at all locations. Control of common dandelion did not consistently increase total forage yield or quality or increase alfalfa yield and stands compared to the untreated check. Buthidazole reduced alfalfa and total forage yield on coarse-textured soils.