bluuebunny/crossref_metadata_2025 huggingface dataset:
Does it Pay to Watch Central Bankers’ Lips? The Information Content of ECB Wording
Authors: Heinemann Friedrich , Ullrich Katrin
Published: January 2018

In this analysis, the informational content of central bank rhetoric is assessed based on the experience with the ECB since 1999. Among the ECB’s communication channels we focus on the monthly press conferences. Based on a counting of certain signal words we construct a wording indicator reflecting the “hawk-ishness” of monetary rhetorics. For the construction, we develop an objective algorithm. We then integrate this indicator into a standard Taylor type ordered probit model for the explanation of the interest rate. We show that the wording indicator can improve the model’s fit when added to the standard explanatory variables. However, a model based solely on this indicator performs worse than the baseline. The results are confirmed by an out of sample analysis where the determination of the wording indicators’ weights is based on the early ECB period which, subsequently, is excluded from the tests. Our conclusion is that linguistic analysis can improve but not substitute more rigorous forecasting techniques based on hard economic data.
Multifunctional Agriculture and the Preservation of Environmental Benefits
Authors: Hediger Werner , Lehmann Bernard
Published: January 2018

We investigate environmental aspects of agriculture from a welfare economic perspective and show that efficiency prices of agricultural and forest land include important amenity and non-use values that exhibit the character of undepletable externalities. To achieve a social optimum these must be internalised, while taking equity concerns into account. We propose compensation of farmers and forest managers according to the marginal external benefit of their land use and a combination of charges and subsidies to improve rural water quality. This is consistent with efficiency requirements and would not cause additional market distortions. Moreover, it would leave the property rights on the land with the farmers and assign the right on clean air and water to the consumers.
What Drives Individual Health Expenditure in Switzerland?
Authors: Bilger Marcel , Chaze Jean-Paul
Published: January 2018

The explanatory factors of individual healthcare consumption are studied by means of healthcare expenditures from the 2000–2005 Swiss Household Income and Expenditure Survey (SHIES). In order to tackle the issues of large number of null expenditures and skewed distribution of positive outcomes, the family of Box-Cox censoring models (Chaze, 2005) is applied. The results show that the use of SHIES data makes it possible to reveal many important factors of individual healthcare consumption, and that the role played by healthcare supply density variables is consistent with the theory of induced demand.
The Determinants of Health Care Utilization in Portugal: An Approach with Count Data Models
Authors: Salvado João Cotter
Published: January 2018

This work aims to identify the determinants of health care utilization in Portugal and to quantify their effects. A clear idea about this may help the policy debate on the delivery and organization of health services. Toward this end, we developed an approach based on count data models. We found that demographic factors influence health care demand; unemployment strongly increases utilization, and income effects are only observed for frequent users. Furthermore, chronic conditions increase demand for health services, and personal habits have mixed effects. Both private insurance and the use of subsystems increase the utilization.
Biased Estimation in a Simple Extension of a Standard Error Correction Model
Authors: Müller Christian
Published: January 2018

This paper considers an expectations augmented version of theEngleandGranger(1987) error correction model and shows that standard inference about the adjustment coefficients can be severely biased. This bias has implications for long-run causality and impulse-response analysis in particular. However, a sometimes simple remedy exists which only requires some additional regressions. The results are illustrated with popular macroeconomic relationships like the Fisher relation and uncovered interest parity hypothesis using U.S., German and Swiss data.
Measuring Capital Stocks and Capital Services in Switzerland
Authors: Rudolf Barbara , Zurlinden Mathias
Published: January 2018

This paper presents estimates of the aggregate net (wealth) capital stock and aggregate capital services for Switzerland. We derive these estimates in a consistent manner using the perpetual inventory method. Due to changes in data availability, the annual time series cover the period 1970–2005 for a 2-asset breakdown (equipment and structures) and 1990–2005 for a 12-asset breakdown (nine categories of equipment and three of structures). The sensitivity of the results is examined by varying assumptions on the initial capital stocks, the length of asset lives, the method for calculating service prices, and the choice of ICT deflators. The paper also presents quarterly measures of capital and estimates of capital services based on mid-year asset stocks.
Estimating a Taylor Rule with Markov Switching Regimes for Switzerland
Authors: Perruchoud Alexander
Published: January 2018

In this paper a Taylor rule including the exchange rate gap is estimated for Switzerland under the assumption that the parameters depend on two states governed by a Markov switching process. The estimates from a Gibbs sampler suggest the presence of a smooth and an active regime. The former is characterized by a high degree of interest rate smoothing. By contrast, the aggressive regime shows much less smoothing. The regime probabilities indicate that Swiss monetary policy is well characterized by the smooth regime with short interruptions by the active regime. Many of these few active periods can be associated with specific and unusual events. Furthermore, the analysis makes clear that often the active regime prevailed in periods where the Swiss National Bank decided to counteract sharp appreciations or depreciations of the Swiss franc.
The role of monetary aggregates in the policy analysis of the swiss national bank
Authors: Kirchgässner Gebhard , Wolters Jürgen
Published: January 2018

Using Swiss data from 1983 to 2008, this paper investigates whether growth rates of the different measures of the quantity of money and or excess money can be used to forecast inflation. After a preliminary data analysis, money demand relations are specified, estimated and tested. Then, employing error correction models, measures of excess money are derived. Using recursive estimates, indicator properties of monetary aggregates for inflation are assessed for the period from 2000 onwards, with time horizons of one, two, and three years. In these calculations, M2 and M3 clearly outperform M1, and excess money is generally a better predictor than the quantity of money. Taking into account also the most (available) recent observations that represent the first three quarters of the economic crisis, the money demand function of M3 remains stable while the one for M2 is strongly influenced by these three observations. While in both cases forecasts for 2010 show inflation rates inside the target zone between zero and two percent, and the same holds for forecasts based on M3 for 2011, forecasts based on M2 provide evidence that the upper limit of this zone might be violated in 2011.
Interest rate dynamics and monetary policy implementation in Switzerland
Authors: Abbassi Puriya , Nautz Dieter , Offermanns Christian J.
Published: January 2018

The maturity of the operational target of monetary policy is a distinguishing feature of the SNB’s operational framework of monetary policy. While most central banks use targets for the overnight rate to signal the policy-intended interest rate level, the SNB announces a target range for the three-month Libor. This paper investigates the working and the consequences of the SNB’s unique operational framework for the behavior of Swiss money market rates before and during the financial crisis.
Test of fiscal sustainability and causality hypotheses for Switzerland
Authors: Prohl Silika
Published: January 2018

This paper examines the causality between the Swiss federal governments revenue and expenditure over the 1900 to 2002 period by estimating the short- and long-run relation within an error-correction approach that places more emphasis on the long-run relation as a source of the causal link. The results suggest both that the fiscal policy is consistent with the governmental budget constraint — revenue and expenditure are cointegrated, and revenue cause expenditure and vice versa. There is also evidence that World War II had a significant impact on the stability of the cointegrating relation between revenue and expenditure.
‘Baumol’s diseases’: The case of Switzerland
Authors: Hartwig Jochen
Published: January 2018

Nordhaus (2008) has developed a testing strategy for what he calls ‘Baumol’s diseases’, by which name he designates a number of by-products of structural change that are unwanted from an economic policy perspective. He finds that the U.S. economy is strongly affected by the ‘diseases’. This paper applies Nordhaus’s testing methodology to Swiss data. The results suggest that — unlike the U.S. — Switzerland is not affected by the most serious of the ‘diseases’, namely the negative impact of structural change on economic growth.
Estimating a stock-flow model for the Swiss housing market
Authors: Steiner Elizabeth
Published: January 2018

This paper analyzes the development of housing market imbalances, housing prices and residential investment in Switzerland within a stock-flow framework. In the long run, the desired level of residential capital stock and the existing residential capital stock revert. Empirical results indicate, however, that housing demand can diverge from the existing supply for several years due to the slow adjustment of the residential capital stock to shocks. In the short run, the market therefore has to be cleared by price adjustments. And indeed, it can be shown empirically that changes in prices are significantly and strongly dependent on the level of stock imbalances. Furthermore, housing prices prove to be an important determinant of residential investment, which in turn drives the adjustment process of the residential capital stock towards its desired level.
Introduction to Energy Systems Modelling
Authors: Herbst Andrea , Toro Felipe , Reitze Felix , Jochem Eberhard
Published: January 2018

The energy demand and supply projections of the Swiss government funded by the Swiss Federal Office of Energy and carried out by a consortium of institutes and consulting companies are based on two types of energy models: macroeconomic general equilibrium models and bottom-up models for each sector. While the macroeconomic models are used to deliver the economic, demographic and policy framework conditions as well as the macroeconomic impacts of particular scenarios, the bottom-up models simulate the technical developments in the final energy sectors and try to optimise electricity generation under the given boundary conditions of a particular scenario. This introductory article gives an overview of some of the energy models used in Switzerland and — more importantly — some insights into current advanced energy system modelling practice pointing to the characteristics of the two modelling types and their advantages and limitations.
The weak rationality principle in economics
Authors: Kirchgässner Gebhard
Published: January 2018

The weak rationality principle is not an empirical statement but a heuristic rule for how to proceed in social sciences. It is a necessary ingredient of any ‘understanding’ social science in the Weberian sense. In this paper, first this principle and its role in economic theorizing are discussed. It is also explained why it makes sense to use a micro-foundation and, therefore, to employ the rationality assumption in economic models. Then, we discuss whether the anomalies of individual behaviour as highlighted in modern behavioural economics impair the applicability of the weak rationality principle. This is not the case. We conclude with some remarks on handling the problems of ‘free will’ as well as ‘weakness of the will’ within the economic approach.
Fiscal institutions at the cantonal level in Switzerland
Authors: Kirchgässner Gebhard
Published: January 2018

In this paper, institutions are described which are designed to reach sustainability of public finances in the Swiss cantons. These are on the one hand direct popular rights, the fiscal referendum in particular, which allow citizens to express their fiscal preferences. These are on the other hand debt breaks, i.e. institutions, which prevent expenditure and revenue from drifting apart too much in order to limit possible deficits. Both together, fiscal referenda and debt breaks, allow cantons to perform a sustainable fiscal policy. This also holds — and is particularly important — for those cantons that are financially weak. That these institutions are successful is not only demonstrated by descriptive analysis but also supported by econometric analyses. Moreover, they also reduce interest payments cantons have to bear for investment expenditure. Thus, with well-designed institutions federal states might even be able to better follow a sustainable fiscal policy than unitary ones.
The determinants of long-run economic growth: A conceptually and computationally simple approach
Authors: Hlouskova Jaroslava , Wagner Martin
Published: January 2018

In this paper we use principal components augmented regressions (PCARs), partly in conjunction with model averaging, to determine the variables relevant for economic growth. The use of PCARs allows to effectively tackle two major problems that the empirical growth literature faces: (i) the uncertainty about the relevance of variables and (ii) the availability of data sets with the number of variables of the same order as the number of observations. The use of PCARs furthermore implies that the computational cost is, compared to standard approaches used in the literature, negligible. The proposed methodology is applied to three data sets, including the Sala-i-Martin, Doppelhofer, and Miller (2004) and Fernandez, Ley, and Steel (2001) data as well as an extended version of the former. Key economic variables are found to be significantly related to economic growth, which demonstrates the relevance of the proposed methodology for empirical growth research.
Natural Hedging of Exchange Rate Risk: The Role of Imported Input Prices
Authors: Fauceglia Dario , Shingal Anirudh , Wermelinger Martin
Published: January 2018

In this paper, we estimate ERPT into imported input prices and export prices using disaggregated quarterly trade data for Switzerland over 2004–2011. We find evidence for high pass-through rates into imported input prices. This demonstrates the effectiveness of natural hedging. On the export side, ERPT exhibits substantial sectoral heterogeneity and changes in imported input costs are not transmitted to foreign consumers in most cases. This suggests the use of cheaper imported inputs to offset adverse effects of currency appreciation on export profit margins.
Valuing Public Investments to Support Bicycling
Authors: Götschi Thomas , Hintermann Beat
Published: January 2018

We develop a framework for assessing the net benefits of investments to promote bicycling, which explicitly accounts for internal costs of bicycling. We apply our model to eight Swiss cities using data from the Swiss national travel survey and find that increasing the level of bicycling by reducing internal costs leads to inframarginal benefits that exceed the net benefits from the additional bicycling. We further find that Swiss cyclists only partially internalize health benefits, which affects the benefits from infrastructure investments but also implies that there is scope for “soft” measures that would inform users about health benefits of bicycling.
A Real-Time Data Set for Switzerland
Authors: Indergand Ronald , Leist Stefan
Published: January 2018

Accessibility of real-time data is crucial for applied macroeconomic researchers who aim at evaluating forecasts, policy decisions or the accuracy of initial data estimates. To the extent of our knowledge, no appropriate and comprehensive real-time data set has been published for Switzerland so far. This paper introduces such a data set, which can be downloaded online. The balanced database includes quarterly, seasonally adjusted vintages of the most important economic variables on the national level. A short analysis of data revisions is provided for quarterly GDP. The magnitude of revisions are comparable to other countries such as the Euro Area or the United States. However, revision policy may differ considerably and potentially influence a statistical analysis.
The Exposure of Mortgage Borrowers to Interest Rate Risk and House Price Risk — Evidence from Swiss Loan Application Data
Authors: Brown Martin , Guin Benjamin
Published: January 2018

We study the exposure of mortgage borrowers in Switzerland to interest rate and house price risks and examine how the households' choice of risky mortgages is related to individual interest rate expectations and risk-aversion. Our analysis is based on a unique data set of household mortgage applications from September 2012 until January 2014. Our assessment of risk exposure among mortgage borrowers in Switzerland is highly sensitive to the underlying assumptions on mortgage costs, household income and house value. Our main results suggest that the exposure of mortgage borrowers to interest rate and house price risks is limited in the medium term. We further document that the choice of mortgage contract seems to be more influenced by affordability concerns than risk concerns. In particular, individual interest rate expectations hardly affect mortgage contract choice.
A Cautionary Note on the Put-Call Parity under an Asset Pricing Model with a Lower Reflecting Barrier
Authors: Hertrich Markus
Published: January 2018

The put-call parity is free from distributional assumptions. It is tempting to assume that this parity also holds when an asset pricing model includes reflecting barriers. This paper shows that in the case of geometric Brownian motion with reflection such barriers cause the standard put-call parity to differ from the riskneutral parity. This paper then analyzes the error that arises when the diffusion is bounded and the standard put-call parity is applied in a risk-neutral framework as a shortcut to impute put prices from call prices, and vice versa. The risk-neutral parity that is derived for a reflected geometric Brownian motion is then used to analyze the impact that the Swiss National Bank’s minimum exchange rate regime vis-à-vis the euro has had on foreign exchange hedging costs. The analysis shows that in the analyzed period domestic investors may have incurred substantial costs as a result of hedging exposure to the euro currency and may have been overexposed to foreign exchange risk.
Capital Markets Union in Europe: Why Other Unions Must Lead the Way
Authors: Acharya Viral V. , Steffen Sascha
Published: January 2018

Government bond markets in the Euro Area are highly fragmented causing further fragmentation in bond and equity markets. Capital Markets Union with fully integrated capital markets across member countries can only work when the status of member country sovereign bonds as risk-free assets is restored. Banking Union and fiscal union are both required for this outcome. However, the Banking Union remains an unfinished project without an European deposit insurance framework and there is little consensus at the moment for a fiscal union in the Euro Area. It appears thus that the fate of the Capital Markets Union solely rests with the European Central Bank in the near to medium term.
Emerging Lessons from Half a Century of Fiscal Federalism in Switzerland
Authors: Schmidheiny Kurt
Published: January 2018

Over the last six years, researchers collaborating through the SNF Sinergia Project have collected data on fiscal federalism in Switzerland over more than half a century. The analysis of these new data in a range of projects has generated new and robust evidence on fiscal interdependencies among local governments and on behavioral responses of households facing local differences This article presents some of the data collected and reports on nine examples of associated research projects.
A Case of Autosplenectomy in Sickle Cell Trait Following an Exposure to High Altitude
Authors: Yanamandra Uday , Das Reena , Malhotra Pankaj , Varma Subhash
Published: January 2018

A 24-year-old man presented with acute abdominal pain upon ascent to moderate altitude (3500 m). An immediate evaluation revealed a splenic infarct, and he was evacuated to sea level. Upon recovery, he was sent back to 3500 m without detailed etiological evaluation, whereupon he experienced recurrent episodes of left-side subcostal pain. Imaging suggested autosplenectomy, and workup revealed a negative thrombophilia profile but was positive for sickle cell trait (SCT). Individuals with SCT can be asymptomatic until exposure to severe hypoxia, upon which they can manifest clinically as sickle cell syndrome. We discuss the rare presentation of autosplenectomy in a patient with previously undiagnosed SCT on exposure to high altitude.
Prenatal vitamin D status and offspring’s growth, adiposity and metabolic health: a systematic review and meta-analysis
Authors: Santamaria Christina , Bi Wei Guang , Leduc Line , Tabatabaei Negar , Jantchou Prévost , Luo Zhong-Cheng , Audibert François , Nuyt Anne Monique , Wei Shu Qin
Published: January 2018

In this systematic review and meta-analysis of observational studies, we aimed to estimate the associations between prenatal vitamin D status and offspring growth, adiposity and metabolic health. We searched the literature in human studies on prenatal vitamin D status and offspring growth in PubMed, up to July 2017. Studies were selected according to their methodological quality and outcomes of interest (anthropometry, fat mass and diabetes in offspring). The inverse variance method was used to calculate the pooled mean difference (MD) with 95 % CI for continuous outcomes, and the Mantel–Haenszel method was used to calculate the pooled OR with 95 % CI for dichotomous outcomes. In all, thirty observational studies involving 35 032 mother–offspring pairs were included. Vitamin D status was evaluated by circulating 25-hydroxyvitamin D (25(OH)D) level. Low vitamin D status was based on each study’s cut-off for low 25(OH)D levels. Low prenatal vitamin D levels were associated with lower birth weight (g) (MD −100·69; 95 % CI −162·25, −39·13), increased risk of small-for-gestational-age (OR 1·55; 95 % CI 1·16, 2·07) and an elevated weight (g) in infant at the age of 9 months (g) (MD 119·75; 95 % CI 32·97, 206·52). No associations were observed between prenatal vitamin D status and other growth parameters at birth, age 1 year, 4–6 years or 9 years, nor with diabetes type 1. Prenatal vitamin D may play a role in infant adiposity and accelerated postnatal growth. The effects of prenatal vitamin D on long-term metabolic health outcomes in children warrant future studies.
Do Financial Analysts Restrain Insiders’ Informational Advantage?
Authors: Ellul Andrew , Panayides Marios
Published: January 2018

By collecting and disseminating price-sensitive information, financial analysts should reduce firm insiders’ informational advantage with a consequent impact on trading dynamics and market quality. We empirically examine the impact of complete analysts’ coverage termination on stocks’ liquidity, price discovery, and insider trading profitability. Termination leads to deteriorating liquidity and price efficiency, more informed trading, and higher profitability of insider trades. The magnitude of these effects depends on the strength of insiders’ ownership and on management’s decision whether to improve the firm’s information environment after coverage termination. Institutional investors alleviate, but do not eliminate, the negative effects of termination.
Biology of Sourgrass and Its Competition with Buffelgrass and Guineagrass
Authors: Pyon J.Y. , Whitney A.S. , Nishimoto R.K.
Published: January 2018

Establishment and early growth characteristics were defined for sourgrass [Trichachne insularis(L.) Nees], one of the most serious pasture weeds in Hawaii. Optimum germination of sourgrass seeds was obtained in the light at 30 C or with alternating temperatures of 20 and 30 C or 25 and 35 C. Germination in complete darkness was poor except at alternating 25 and 35 C. Sourgrass germinated better than buffelgrass (Cenchrus ciliarisL.) and guineagrass (Panicum maximumJacq.) at low moisture tension. Sourgrass was capable of emerging from a maximum depth of 5 cm but percent emergence was greatly reduced at planting depths greater than 3 cm. Sourgrass flowering response to photoperiod was day-neutral. Under conditions of adequate moisture, the growth of sourgrass was severely suppressed when grown with buffelgrass, or/or guineagrass. If grazing is restricted, either of these grasses would be useful for controlling sourgrass.
Competitive Mechanisms of Common Cocklebur (Xanthium strumarium) and Soybean (Glycine max) During Seedling Growth
Authors: Bozsa Robert C. , Oliver Lawrence R.
Published: January 2018

Experiments were conducted in the greenhouse and growth chamber to evaluate competitive mechanisms of soybean and common cocklebur during seedling growth. Soybean was approximately 1.5 to 2 times taller and was more competitive aboveground than common cocklebur during the first few weeks of growth. Common cocklebur had an approximate 20 to 50% finer root system and was more competitive belowground than soybean during early growth.
Common Lambsquarters (Chenopodium album) Competition and Time of Removal in Soybeans (Glycine max)
Authors: Crook Teresa M. , Renner Karen A.
Published: January 2018

Field studies were conducted in 1987 and 1988 to evaluate the control and competitiveness of common lambsquarters in soybeans when present at four densities and when removed at four time intervals. Common lambsquarters were removed by hand or treated with a postemergence herbicide application of bentazon plus acifluorfen. Common lambsquarters could remain 10 weeks following soybean emergence before a 20% soybean yield reduction occurred when weeds were removed by hand. When treatment was attempted with postemergence herbicides, a 20% yield reduction occurred in 1987 if application was not made prior to 5 weeks after emergence. In 1988, all postemergence herbicide applications failed to control lambsquarters due to drought conditions. The postemergence herbicide's degree of control was reflected in the number of remaining lambsquarters plants. Common lambsquarters seed production and germination was not influenced by postemergence herbicide application. There was a strong correlation between dry weight of uncontrolled common lambsquarters plants and seed produced per plant.
Texas Panicum (Panicum texanum) Growth as Affected by Irrigation Management and Planting Date
Authors: Schroeder Jill , Dowler Clyde C. , Stansell James R.
Published: January 2018

The effect of soil matric potential from −0.02 to <–1.5 MPa on Texas panicum growth in drainage lysimeters covered by an automatic rainfall shelter was measured in 1984, 1985, and 1986. Rate of tiller production was faster for plants established in April than June in 1984 and 1985, but not 1986. In 1985 and 1986, dry weight was greater, but total seed production was less for plants established in April than June. Irrigation when the soil matric potential was −0.02, −0.075, or −1.5 MPa did not affect rate of tiller production in 1984. Irrigation when the soil matric potential was −1.5 MPa decreased dry weight of plants but increased seed number per panicle compared to irrigation when the soil matric potential was −0.02 MPa in 1985 and 1986. Plants grown in lysimeters irrigated at soil matric potential <–1.5 MPa in 1985 and 1986 did not wilt at 8:00 a.m.; therefore, they were not watered after establishment. These nonirrigated plants averaged 0.9 and 0.4 kg dry weight and produced 92 200 and 16 100 seeds in 1985 and 1986, respectively.
The Effects of Supplemental Nitrogen on Shoot Production and Root Bud Dormancy of Canada Thistle (Cirsium arvense) under Field Conditions
Authors: Nadeau Léonie B. , Vanden Born William H.
Published: January 2018

We examined effects of supplementary nitrogen on young Canada thistle stands in Alberta, Canada. Urea applied at 70 or 100 kg N ha–1increased shoot population densities, mostly through increased root growth in the top 20 cm of soil rather than through released root bud dormancy. Nitrogen fertilization, therefore, may increase the severity of a Canada thistle infestation. In 1-yr-old stands, the number of emerged and unemerged root buds/m of root was higher near the soil surface in fertilized plots than in unfertilized plots, and no underground shoots were detected at the time of sampling. In 2-yr-old stands, more unemerged root buds/m of root were found at depths below 20 cm in fertilized plots than in unfertilized plots, and twice as many underground shoots/m of root occurred between 20 and 40 cm in fertilized plots as in unfertilized plots. However, no effect of nitrogen on the number of emerged root buds was detected. Nitrogen treatment increased shoot production only for those replanted root fragments from deeper than 60 cm in 1-yr-old stands and deeper than 160 cm in 2-yr-old stands.
Eastern Black Nightshade (Solanum ptycanthum) Interference in Processing Tomato (Lycopersicon esculentum)
Authors: Perez Frances G. M. , Masiunas John B.
Published: January 2018

In replacement experiments in the greenhouse, plant relative yield (PRY) of both eastern black nightshade and tomato increased as the proportion of nightshade plants increased in the pots, indicating that nightshade is less competitive than tomato. In field studies tomato yield was reduced by two-thirds if three nightshade plants m–1of row were allowed to grow with tomato more than 6 weeks following tomato establishment The percent marketable fruit decreased linearly from 73% with no nightshade to 49% when nightshade were present for 12 weeks. When nightshade and tomato were transplanted together, tomato yield was 9000 kg ha–1and 49% of the fruit was marketable, while tomato yields were 30 000 kg ha–1and 70% of the fruit was marketable when nightshade was established 9 weeks after tomato planting.
Transformation of Alachlor by Microbial Communities
Authors: Sun Hone L. , Sheets Thomas J. , Corbin Frederick T.
Published: January 2018

A mixed microbial culture able to transform alachlor at a concentration of 50 μg ml-1was obtained from alachlor-treated soil after an enrichment period of 84 days. The microbial community was composed of seven strains of bacteria. No single isolate was able to utilize alachlor as a sole source of carbon. There was no alachlor left in the enriched culture after a 14-day incubation, but only 12% of the14C-ring-labeled alachlor was converted to14CO2through ring cleavage during 14 days in the basal medium amended with alachlor as a sole carbon source. The presence of sucrose as an alternative carbon source decreased the mineralization potential of the enriched culture, but sucrose increased the mineralizing ability of a three-member mixed culture. Thin-layer chromatographic analysis showed that there were four unidentified metabolites of alachlor produced by the enriched culture. Sucrose decreased the amount of two of the four metabolites. The absence of a noticeable decline in radioactivity beyond the initial 12% suggested that the side chain of alachlor was utilized as carbon source by the enriched culture. Little difference in radioactivity between growth medium and cell-free supernatant of the growth medium suggested that the carbon in the ring was not incorporated into the cells of the degrading microorganisms.
Detection of Herbicides Using Fluorescence Spectroscopy
Authors: Mueller Thomas C. , Moorman Thomas B. , Locke Martin A.
Published: January 2018

Fluorescence spectroscopy offers several advantages over other methods of detection and quantitation of chemical compounds. This technique has been underutilized in detection and quantitation of herbicides. The fluorescence properties of 39 herbicides representing several major types of chemistry were determined. The fluorescence of analytical standards was measured in acetonitrile, acetonitrile + water, and acetonitrile + water + strong acid. Fourteen of the 39 herbicides fluoresced to some extent, and seven (bentazon, chloramben, difenzoquat, fluometuron, imazaquin, MCPA, and norflurazon) were identified as good candidates for further method development. The technical advantages and disadvantages of fluorescence spectroscopy of herbicides are discussed.
Economic Impact of Leafy Spurge (Euphorbia esula) in North Dakota
Authors: Leistritz F. Larry , Thompson Flint , Leitch Jay A.
Published: January 2018

Leafy spurge is a serious problem because of the speed with which it spreads and the difficulty of controlling it with available means. A rangeland economics model was developed to estimate the economic impacts of leafy spurge infestation on both ranchers and regional economies. A leafy spurge-induced carrying capacity reduction of about 580 000 animal unit months (AUMs), or enough for 77 000 cows, reduced ranchers' annual net income nearly $9 million. Ranchers did not spend another $14 million on input costs, which reduced regional business activity. The regional impacts are about $75 million in reduced business activity for all sectors. These impacts on rancher incomes and regional economies suggest the potential economic returns of leafy spurge control could be substantial.
Use of Ecophysiological Models for Crop-Weed Interference: Relations Amongst Weed Density, Relative Time of Weed Emergence, Relative Leaf Area, and Yield Loss
Authors: Kropff M. J. , Weaver S. E. , Smits M. A.
Published: January 2018

The performance of a mechanistic simulation model of crop-weed competition was evaluated with data on the effects of weed density, relative time of weed emergence, and environmental conditions on crop yield for three different crop-weed combinations. Reductions in crop yields due to weed competition were simulated accurately for all experiments, except for one case in which severe water stress combined with weed competition altered crop morphological development (height and leaf area). The mechanistic model was then used to assess the potential and constraints of two empirical models of crop-weed competition, one based upon weed density and relative time of emergence, and the other on relative leaf area. The empirical model describing the relationship between relative leaf area of the weeds shortly after crop emergence and yield loss appeared to have several advantages for management applications, whereas the mechanistic model is more suited for research purposes.
Use of Ecophysiological Models for Crop-Weed Interference: The Critical Period of Weed Interference
Authors: Weaver S. E. , Kropff M. J. , Groeneveld R.M.W.
Published: January 2018

The performance of a mechanistic simulation model of crop-weed competition was tested with data on the critical period of weed competition in sugarbeets and both seeded and transplanted tomatoes. In general, there was good agreement between simulated and observed yields for different periods of weed interference in each crop. The model was then used to evaluate the influence of weed density, weed height, and weather conditions on timing of the critical period. Simulations suggested that the greater the weed density, the shorter the period of time that the crop could tolerate early-season competition, and the longer the period of time that the crop must be kept weed free to prevent yield losses. Simulations also suggested that the length of time that a crop can tolerate early-season weed competition is related more to the availability of soil moisture, or possibly essential nutrients, than to light limitations.
Path Analysis of Red Rice (Oryza sativaL.) Competition by Cultivated Rice
Authors: Pantone D. J. , Baker J. B. , Jordan P. W.
Published: January 2018

During 1985 to 1989, a series of field experiments were conducted at the Rice Research Station in Crowley, LA. Path analysis was employed to evaluate the competitive interaction between a weed (red rice) and cultivated rice (Mars). The path analysis quantified direct effects of red rice and Mars rice densities on the yield components (grain weight, percent filled florets, number of florets panicle−1, and panicles plant−1) of red rice and Mars rice. The model illustrated the direct and indirect effects of the yield components on fecundity and grain yield plant−1. The direct effects of Mars and red rice densities on panicles plant−1and florets panicle−1were always negative. In contrast, the effects of density on percent filled florets and grain weight varied from positive to negative and were relatively small, implying that they were determined primarily by density-independent factors. Path analysis indicated that the number of panicles plant−1and florets panicle−1were the most important yield components determining the responses of fecundity and grain yield to competition.
Biological Control of Ducksalad (Heteranthera limosa) by the Waterlily Aphid (Rhopalosiphum nymphaeae) in Rice (Oryza sativa)
Authors: Oraze Michael J. , Grigarick Albert A.
Published: January 2018

Ducksalad, an annual broadleaf weed in rice, was infested by waterlily aphid which destroyed much of the above-water vegetation. Field experiments showed aphids reduced total weed biomass by 58 and 87% in 1985 and 1986, respectively. Biomass of seed pods was reduced by more than 82% in both years.
Metribuzin Absorption and Translocation in Two Barley (Hordeum vulgare) Cultivars
Authors: Gawronski Stanislaw W. , Haderlie Lloyd C. , Stark Jeffrey C.
Published: January 2018

Root and foliar absorption and translocation of14C-metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] were determined in tolerant (‘Steptoe’) and susceptible (‘Morex’) barley (Hordeum vulgareL.) cultivars grown in nutrient solution culture under greenhouse conditions. Root-applied metribuzin toxicity to the two barley cultivars was also examined. A 50% reduction in growth occurred at 0.22 and 0.72 μM metribuzin for Morex and Steptoe, respectively. Root absorption was similar for both cultivars at 1 day, but Steptoe absorbed about two times more metribuzin 4 and 8 days after application than did Morex. Steptoe absorbed 19% of the total applied metribuzin by 8 days. Root absorption was positively correlated with water uptake (r≥ 0.87). Leaf absorption was three times greater for Morex than for Steptoe after 4 days. Transport to leaves from root application was rapid, and, by 1 and 8 days, leaves of Steptoe contained 71 and 82% and leaves of Morex 78 and 84% of the total absorbed14C, respectively. Translocation was apoplastic following both root and leaf absorption and was similar for both cultivars. Differential tolerance could partially be accounted for by differences in foliar absorption but not by differences in root absorption.
Effects of Haloxyfop on Corn (Zea mays) and Soybean (Glycine max) Cell Suspension Cultures
Authors: Cho Hyung-Yul , Widholm Jack M. , Slife Fred W.
Published: January 2018

To investigate the mode of action of a grass-specific herbicide, haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} was added to corn and soybean cell suspension cultures containing metabolic intermediates such as sucrose [14C-U], sodium acetate [14C-1,2], or L-leucine [14C-U]. Death of the corn suspension cells occurred within 3 days after haloxyfop was added at a concentration of 1.0μM to supplemented Murashige and Skoog's medium. At 0.1μM haloxyfop,14C-sucrose uptake and14C loss due to respiration of the corn cells declined without a significant reduction in cell fresh weight, cell viability, cellular ATP level, free sugar content, cell wall materials, or level of glycolytic intermediates. The proportions of sucrose, glucose, and fructose in the free sugar fraction were not affected. However, the14C-labeled free amino acid level was increased. During a 24-h incubation period, incorporation of leucine [14C] as a precursor revealed that haloxyfop did not inhibit protein synthesis. Incorporation of acetate [14C-1,2] showed that total lipid synthesis was inhibited by 42% at 0.1μM haloxyfop (sublethal). Similar responses were observed in the soybean suspension cells; however, the calculated 50% lethal concentration (LC50) was 47 times higher than for corn cells. The results of this study suggest that the site of action of haloxyfop is located where metabolic intermediates enter the Kreb's cycle and lipid synthesis. Glycolysis is not inhibited.
Germination of Horse Purslane (Trianthema portulacastrum) in Relation to Temperature, Storage Conditions, and Seeding Depths
Authors: Balyan R. S. , Bhan V. M.
Published: January 2018

Horse purslane (Trianthema portulacastrum L. # TRTPO) seeds germinated from 20 to 45 C. Maximum germination of 90% was observed at 35 C. Germination was highest between the 4th and 8th days of incubation. Horse purslane seeds did not exhibit dormancy. Freshly harvested seeds when incubated at 35 C germinated to the extent of 54 to 56%. Seed germination steadily increased up to 7 and 8 months when stored under laboratory and field conditions, respectively. Seeds stored in soil had significantly higher germination than those stored in the laboratory. Maximum seedling emergence resulted when seeds were planted at 1 cm and gradually declined with the increased seeding depth. Seeds lying on the surface gave very poor seedling emergence.
Weed Seed Response to Methyl Isothiocyanate and Metham
Authors: Teasdale John R. , Taylorson Ray B.
Published: January 2018

Methyl isothiocyanate (MIT) consistently killed large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA] seed at concentations of 4.0 mM or greater. Concentrations of 0.6 to 1.0 mM MIT delayed germination of large crabgrass seed but ultimately allowed the majority of seed to germinate. Dormant large crabgrass seed were killed at concentrations of MIT similar to those required to kill nondormant seed. MIT stimulated germination of dormant large crabgrass seed at sublethal concentrations (0.1 to 1.0 mM). Experiments with metham (sodium methyldithiocarbamate) in the greenhouse and field (metham rapidly degrades to MIT in soils) confirmed results of laboratory experiments with MIT.
Population, Temperature, and Substrate Influences on Common Milkweed (Asclepias syriaca) Seed Germination
Authors: Farmer Janis M. , Price Steven C. , Bell C. Ritchie
Published: January 2018

Seed from 21 common milkweed (Asclepias syriacaL. # ASCSY) populations from six states were germinated on six substrates (filter paper, sand, peat, clay, and mixtures) under three temperature regimes. The variation in germination response between populations and experimental conditions was analyzed. The greatest percent germination (59% average over all substrates) was obtained with an alternating 20 C (16 h), 30 C (8 h) temperature regime. At a constant temperature of 30 C, germination was lower (32% average) and much more variable among seeds from different populations. At 25 C, average percent germination dropped to 1.2% over all substrates. Germination appeared to be strongly correlated with seed source (population), temperature, and substrate type, and poorly correlated with seed size. No association was found between geographical origin and germination response.
Enhanced Herbicide Biodegradation in South Carolina Soils Previously Treated with Butylate
Authors: Skipper H. D. , Murdock E. C. , Gooden D. T. , Zublena J. P. , Amakiri M. A.
Published: January 2018

Experiments were conducted to investigate enhanced biodegradation of carbamothioates and to evaluate the effect of microbial inhibitors on the efficacy of butylate [S-ethyl bis(2-methylpropyl)carbamothioate], EPTC (S-ethyl dipropylcarbamothioate), and vernolate (S-propyl dipropylcarbamothioate) in soils that had received butylate treatment in previous years (butylate-history soils). Inhibitors used were fonofos (O-ethyl-S-phenylether phosphonodithioate) and R-33865 (O,O-diethyl-O-phenylphosphorothioate). R-33865 and fonofos significantly improved control of large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA] with butylate and EPTC in corn (Zea maysL. ‘Coker 21’). Bioassay data reflected more residual phytotoxicity from butylate and EPTC when these herbicides were combined with the microbial inhibitors. In butylate-history soils planted to soybeans [Glycine max(L.) Merr. ‘Wright’], R-33865 did not improve the efficacy of vernolate. These results indicated some cross-adaptation of the butylate-adapted microorganisms for EPTC, but no cross-adaptation was detected for vernolate. Under laboratory conditions,14C-butylate was degraded more rapidly to14CO2in butylate-history soils than in non-butylate-history soils.
Absorption and Translocation of Fluazifop with Additives
Authors: Nalewaja John D. , Skrzypczak Grzegorz A.
Published: January 2018

The influence of various additives on the absorption and translocation of fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid} butyl ester in oats (Avena sativaL. var. ‘Lyon’) was determined. Fluazifop absorption and translocation by oats 48 h after application were less when applied with safflower (Carthamus tinctoriusL.), sunflower (Helianthus annuusL.), soybean [Glycine max(L.) Merr.], linseed (Linum usitatissimumL.), and palm (Eleais quineeneisJacq.) oil than with petroleum oil. However, fluazifop absorption and translocation continued to increase for the 96-h duration of the experiment when applied with soybean oil but only for 24 h when applied with petroleum oil. The14C-fluazifop-label recovery was higher when applied with oils than when applied alone, which may have been due to reduced fluazifop volatility when it was emulsified with the oils. Absorption and translocation of fluazifop applied with glycerol or various emulsifiers were equal to or less than fluazifop absorption and translocation when applied with petroleum oils but were greater than fluazifop absorption and translocation when applied with seed oils 48 h after application. Fluazifop absorption and translocation were similar whether soybean or petroleum oil additives were applied with or without emulsifiers. Totally refined seed oils only slightly increased fluazifop absorption and translocation compared to fluazifop with once-refined or degummed seed oils.
Weed Control in No-Till Sorghum (Sorghum bicolor)
Authors: Wicks Gail A. , Grabouski Phil H.
Published: January 2018

Field research was conducted in Nebraska to evaluate the efficacy of herbicides for the control of summer annual weeds in sorghum [Sorghum bicolor(L.) Moench.]. During 1976 to 1979, no-till plots treated with a mixture of paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine], and terbutryn [N-(1,1-dimethylethyl)-N′-ethyl-6-(methylthio)-1,3,5-triazine-2,4-diamine] yielded 33% more sorghum grain than plots receiving the same herbicides when a seedbed was prepared by disking. During 1981 to 1983, season-long weed control was obtained with acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl) acetamide], alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide], cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl] amino]-2-methylpropanenitrile}, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], or terbutryn added to paraquat plus atrazine and metolachlor plus cyanazine plus paraquat applied 10 days prior to planting. The use of seed safeners did not increase sorghum yield.