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| Registros recuperados: 260 | |
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| Sell, Randall S.; Bangsund, Dean A.; Leistritz, F. Larry; Nudell, Daniel J.. |
| A survey of 459 ranchers was conducted to evaluate managerial, institutional, and social factors that may affect the rate and extent of implementation of various leafy spurge (Euphorbia esula L.) controls in a five-county region in Montana, North Dakota, South Dakota, and Wyoming. Ranchers returned 187 questionnaires. Weeds were considered a greater problem for ranchers with leafy spurge than for those without leafy spurge; however, even among ranchers with leafy spurge, there was strong agreement that other ranching issues were of greater concern. Over 65 percent of the respondents indicated that weeds on their ranch were a `minor problem.' Leafy spurge was ranked as the most important weed. Nearly 60 percent of ranchers felt that using herbicides,... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Leafy spurge; Control; Rancher opinion; Farm Management; Resource /Energy Economics and Policy. |
| Ano: 1998 |
URL: http://purl.umn.edu/23456 |
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| Sell, Randall S.; Bangsund, Dean A.; Leistritz, F. Larry; Nudell, Daniel J.. |
| A survey of 459 ranchers was conducted to evaluate managerial, institutional, and social factors that may affect the rate and extent of implementation of various leafy spurge (Euphorbia esula L.) controls in a five-county region in Montana, North Dakota, South Dakota, and Wyoming. Ranchers returned 187 questionnaires. Weeds were considered a greater problem for ranchers with leafy spurge than for those without leafy spurge; however, even among ranchers with leafy spurge, there was strong agreement that other ranching issues were of greater concern. Over 65 percent of the respondents indicated that weeds on their ranch were a `minor problem.' Leafy spurge was ranked as the most important weed. Nearly 60 percent of ranchers felt that using herbicides,... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Leafy spurge; Control; Rancher opinion; Farm Management; Resource /Energy Economics and Policy. |
| Ano: 1998 |
URL: http://purl.umn.edu/23186 |
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| Adams, Damian C.; Lee, Donna J.. |
| The invasive aquatic plants Hydrilla verticillata (hydrilla), Eichhornia crassipes (water hyacinth), and Pistia stratiotes (water lettuce) have the potential to negatively impact recreational use of Florida lakes if consistent, adequate control expenditures are not made. In the mid-1990's, Florida significantly reduced its spending on invasive aquatic plant control measures, which resulted in a significant increase in needed control expenditures in subsequent years. This paper attempts to formalize a relationship between coverage of these invasive aquatic plants and angler effort on Florida lakes using data on 38 lakes over 20 years. Estimated regression coefficients are used to simulate control alternatives, and expenditure cost-benefit comparisons are... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Hydrilla; Water hyacinth; Water lettuce; Bioeconomic; Invasive; Control; Resource /Energy Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/19146 |
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| Chalak, Morteza; Ruijs, Arjan; Hemerik, Lia; van der Werf, Wopke; van Ierland, Ekko C.. |
| Natural enemies such as herbivores that are introduced to reduce invasive plants can spill over into nature, threaten indigenous species and impose significant costs. We develop a bioeconomic model to analyse the optimal control management strategy of an introduced herbivore that has spilled over from a managed system to a natural area. Cost-effective control strategies are analysed that reduce the spillover effects of herbivores on endangered plants species to reduce the risk of extinction and increase benefits obtained from the ecosystem. We consider two competing indigenous plant species as the representatives of the plant community. Only one of these species is consumed by introduced herbivore. We show that the optimal level of controlling herbivores... |
| Tipo: Presentation |
Palavras-chave: Economics; Biological agent; Externality; Spillover; Control; Environmental Economics and Policy. |
| Ano: 2012 |
URL: http://purl.umn.edu/124374 |
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| Kim, C.S.; Lubowski, Ruben N.; Lewandrowski, Jan; Eiswerth, Mark E.. |
| We present a conceptual, but empirically applicable, model for determining the optimal allocation of resources between exclusion and control activities for managing an invasive species with an uncertain discovery time. This model is used to investigate how to allocate limited resources between activities before and after the first discovery of an invasive species and the effects of the characteristics of an invasive species on limited resource allocation. The optimality conditions show that it is economically efficient to spend a larger share of outlays for exclusion activities before, rather than after, a species is first discovered, up to a threshold point. We also find that, after discovery, more exclusionary measures and fewer control measures are... |
| Tipo: Journal Article |
Palavras-chave: Invasive species; Exclusion; Control; Eradication; Public expenditures; Environmental Economics and Policy; Resource /Energy Economics and Policy. |
| Ano: 2006 |
URL: http://purl.umn.edu/10176 |
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| Longworth, Natasha; Jongeneel, Roelof A.; Saatkamp, H.W.; Huirne, Ruud B.M.. |
| The new EU Animal Health Strategy suggests a shift in emphasis away from control towards prevention and surveillance activities for the management of threats to animal health. The optimal combination of these actions will differ among diseases and depend on largely unknown and uncertain costs and benefits. This paper reports an empirical investigation of this issue for the case of Avian Influenza. The results suggest that the optimal combination of actions will be dependent on the objective of the decision maker and that conflict exists between an optimal strategy which minimises costs to the government and one which maximises producer profits or minimises negative effects on human health. From the perspective of minimising the effects on human health,... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Avian influenza; Prevention; Control; Livestock Production/Industries. |
| Ano: 2008 |
URL: http://purl.umn.edu/44200 |
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| Stott, Alistair W.; Milne, Catherine E.; Gunn, George J.. |
| An epidemiological model is described that closely mimicked results of a published serological study of natural transmission of Maedi-Visna virus in a low ground flock of sheep. We adjusted parameters in the model from this baseline to explore the possible implications for the control of Maedi-Visna virus in typical British flocks. On closed hill farms, low probability of effective contact was most critical for control. In open low ground flocks, purchasing accredited replacements eliminated disease spread, otherwise flock size was the most important factor governing flock prevalence. Results highlighted the need for more epidemiological information about Maedi-Visna, particularly whether hill farms act as a hidden reservoir of virus or reduce the impact... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Livestock Production/Industries; Maedi-Visna; Model; Markov Chain; Sheep; Control. |
| Ano: 2009 |
URL: http://purl.umn.edu/61102 |
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| Frentrup, Mechthild; Theuvsen, Ludwig. |
| Transparency has gained much relevance in food chains. This paper summarizes the determinants of transparency and points out that transparency in the sense of effective information exchange needs trust as a mediator in order to become a powerful tool in supply chain management. In addition to that this paper analyses the characteristics of trust and highlights the reciprocal and dynamic mechanisms of trust on transparency and vice versa. It is argued that both constructs should be enhanced at the same time in order to realize the benefits of trust and transparency on supply chain management. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Transparency; Trust; Power; Control; Agribusiness; Agribusiness. |
| Ano: 2006 |
URL: http://purl.umn.edu/7733 |
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| Jones,RC. |
| The emergence and nature of different strains of infectious bronchitis virus (IBV) in Europe are described. Infectious bronchitis (IB) is the most important endemic viral respiratory disease where highly pathogenic Newcastle disease and avian influenza are not present. IB was first described in the UK in 1948 and identified as Massachusetts type. In the 1970s and 80s new serotypes were reported in Holland and elsewhere and new vaccines were developed. The 1990s saw the emergence of the major variant commonly called 793B, again needing a new vaccine. Two novel types have been recognised since 2000, Italy 02 and QX. Italy 02 appears to be well controlled by the use of two different live vaccines (H120 and the 793B-related 4/91) while for QX, associated with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Control; Chickens; Europe; Infectious bronchitis; Vaccine. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2010000200009 |
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| Cardoso,Josiane Teresinha; Lázzari,Sonia Maria Noemberg. |
| Adults and larvae of coccinellids were observed feeding on populations of the giant conifer aphids Cinara spp. on Pinus spp., in Southern Brazil. The objective of this research is to evaluate the consumption capacity of Cycloneda sanguinea (Linnaeus, 1763) and Hippodamia convergens Guérin-Méneville, 1842 (Coleoptera, Coccinellidae) on these aphid species, in order to obtain information for biological control programs. Ten larvae of each predator species were fed with aphids of small size (nymphs of 1st and 2nd instars), and 10 with aphids of medium size (nymphs of 3rd and 4th instars), maintained under 15ºC, 20ºC and 25ºC, 12 h photophase and 70 ± 10% relative humidity. The aphids were counted every 24 hours, replacing those that were consumed. The total... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Control; Giant conifer aphids; Pinaceae; Prey-predator relationship. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262003000400004 |
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| Silva,William Ribeiro da; Soares-da-Silva,Joelma; Ferreira,Francisco Augusto da Silva; Rodrigues,Iléa Brandão; Tadei,Wanderli Pedro; Zequi,João Antonio Cyrino. |
| ABSTRACT The aim of this study was to analyze the effectiveness of different control agents of Aedes aegypti and Aedes albopictus associated with ovitraps under laboratory and field conditions. Five treatments were used: grass infusion + Bacillus thuringiensis israelensis (gI + Bti), grass infusion + Saccharopolyspora spinosa (gI + Ss), grass infusion + Pyriproxyfen (gI + P), distilled water + Toxorhynchites haemorrhoidalis (dW + Th), and grass infusion (gI) (control). The highest mean number of eggs of both species were obtained with grass infusion in the laboratory. Among control agents, the lowest mean of A. aegypti eggs occurred with gI + Ss and the lowest mean of A. albopictus eggs occurred with dW + Th. There was no difference between treatments in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chikungunya; Control; Dengue; Insecticides; Zika. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262018000400304 |
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| Narváez,Yimmy Alexander Zapata; Beltrán-Acosta,Camilo Rubén. |
| Abstract The production of blackberry in Colombia is a source of income and rural employment in 18 departments; however, the plant is affected by diseases such as gray mold, anthracnose and powdery mildew that can cause losses of up to 70%. The control of these diseases is mainly carried out with chemical fungicides such as benomyl, carbendazim and mancozeb applied every 7 or 15 days. Nevertheless, being a continuous fructification plant of weekly harvest, the proximity between the application of the pesticides, the harvest, and its consumption represents a health risk due to the residually of these molecules, condition that affects its innocuousness and sustainability. Accordingly, this work aimed to develop an integrated management strategy for these... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Control; Efficacy; Food safety; Environmental impact; Residuality. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452019000500406 |
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| Colley,Eduardo; Fischer,Marta Luciane. |
| The giant African snail Achatina fulica Bowdich, 1822 was introduced into Paraná, Brazil, in the 1980s. Since then, it has spread across the country, despite its known invasive status on a global scale. The main objective of this study was to assess the problems faced in the management of the giant African snail. To accomplish that, we gathered and analyzed information available on the internet, scientific databases, field studies, as well as interviews and consultations with official agencies, NGOs, museums, the scientific community and people that coexist with the species. Despite the fact that extensive information has been generated regarding A. fulica (1,340 articles, 65 summaries in national annals, 40,700 pages on the internet), essential to promote... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biological invasions; Control; Economic; Environmental; Impacts; Invasive exotic species; Health. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000400012 |
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| Registros recuperados: 260 | |
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