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| Registros recuperados: 22 | |
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| Cacho, Oscar J.; Jones, Randall E.. |
| It is argued in this paper that static approaches to weed management, where the benefits and costs are only considered within a single season, are inappropriate for assessing the economic benefits of weed control technologies. There are carryover effects from weed management as weeds that escape control in one season may reproduce and replenish weed populations in following seasons. Consequently, it is appropriate to view weed control in the context of a resource management problem where the goal is to determine the optimal inter-temporal level of weed control that maximises economic benefits over some pre-determined period of time. A dynamic optimisation model for weed control is presented. Using the tools of comparative static analysis and Pontryagin's... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Weed control; Resource economics; Optimal control; Dynamic programming; Wild oats; Farm Management. |
| Ano: 2000 |
URL: http://purl.umn.edu/12902 |
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| Jones, Randall E.; Cacho, Oscar J.. |
| It is argued in this paper that static approaches to weed management, where the benefits and costs are only considered within a single season, are inappropriate for assessing the economic benefits of weed control technologies. There are carryover effects from weed management as weeds that escape control in one season may reproduce and replenish weed populations in following seasons. Consequently, it is appropriate to view weed control in the context of a resource management problem where the goal is to determine the optimal inter-temporal level of weed control that maximises economic benefits over some pre-determined period of time. A dynamic optimisation model for weed control is presented. Using the tools of comparative static analysis and Pontryagin's... |
| Tipo: Presentation |
Palavras-chave: Crop Production/Industries. |
| Ano: 2000 |
URL: http://purl.umn.edu/123685 |
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| Wittwer, Glyn; Vere, David T.; Jones, Randall E.; Griffith, Garry R.. |
| A recent analysis indicated that the direct financial cost of weeds to Australia’s winter grain sectorwas approximately $A1.2bn in 1998–1999. Costs of thismagnitude represent a large recurring productivity loss in an agricultural sector that is sufficient to impact significantly on regional economies.Using amulti-regional dynamic computable general equilibrium model, we simulate the general equilibrium effects of a hypothetical successful campaign to reduce the economic costs of weeds. We assume that an additional $50m of R&D spread over five years is targeted at reducing the additional costs and reduced yields arising from weeds in various broadacre crops. Following this R&D effort, one-tenth of the losses arising from weeds is temporarily... |
| Tipo: Article |
Palavras-chave: CGE modelling; Dynamics; Weed management; Crop Production/Industries. |
| Ano: 2005 |
URL: http://purl.umn.edu/118584 |
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| Vere, David T.; Jones, Randall E.; Griffith, Garry R.. |
| The present paper reports an economic evaluation of the long-term benefits to Australia of research by the Cooperative Research Centre for Weed Management Systems (CRC) into the improved management of vulpia , the major annual grass weed of temperate pastures in New South Wales and Victoria. Vulpia reduces livestock production by competition with more desirable pasture species, by the production of low quality feed at critical times of the grazing cycle, and by injury to animals. A 20-year stochastic benefit-cost analysis indicated that reducing the impacts of vulpia in these pastures produced a mean net present value of # A58.3 million and a mean benefit-cost ratio of 33:1. Temperate pasture zone wool producers would capture the largest shares of these... |
| Tipo: Journal Article |
Palavras-chave: Agricultural and Food Policy; Farm Management. |
| Ano: 2003 |
URL: http://purl.umn.edu/118162 |
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| Marshall, Graham R.; Wall, Lisa M.; Jones, Randall E.. |
| Integrated Catchment Management (ICM) can be viewed as an institutional instrument designed to ameliorate losses of economic efficiency that have arisen due to incomplete specification of the privileges and restrictions attached to property rights. If applied appropriately ICM can facilitate the emergence of a market in which parties disadvantaged by incomplete specification attempt to bribe those advantaged, with the aim of obtaining the latter's agreement to more complete specification. The instrument provides potential for transactions costs of bargaining to be reduced substantially by reducing the number of parties eligible to participate in, and installing the state as broker and arbiter of, the bargaining process. Participation by sub-catchment... |
| Tipo: Journal Article |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 1996 |
URL: http://purl.umn.edu/12415 |
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| Islam, Q.; Mullen, John D.; Brennan, John P.; Li, G.D.; Helyar, K.R.; Jones, Randall E.. |
| Acid and acidifying soils occur extensively in Australia. Currently, some 90 million hectares of agricultural land in Australia is considered to be acidic and around 35 million hectares are considered to be highly acidic which is both a serious agricultural and environmental problem. The nature, impact, and causes of soil acidification vary across Australia, as do farming systems and the institutional and socioeconomic issues relating to land management. In high-rainfall areas of south-eastern Australia, managing acid soils is particularly difficult in permanent pasture systems. In this paper, an economic analysis is made of the results of a long-term trial (MASTER – Managing Acid Soils Through Efficient Rotations) aimed at developing a sustainable... |
| Tipo: Presentation |
Palavras-chave: Soil acidity/pH/amelioration/farming/rotations/gross margin/stocking rates; Crop Production/Industries; Farm Management. |
| Ano: 1999 |
URL: http://purl.umn.edu/123818 |
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| Jones, Randall E.; Marshall, Graham R.. |
| Soil salinisation and waterlogging are significant problems in the Irrigation Areas and Districts of southern New South Wales. Various actions can be taken at either a regional or farm level to alleviate these problems. District surface drainage, sub-surface drainage, pumping from deep aquifers and changes to water pricing policies are regional options, while possible on-farm options include laser controlled landforming, pumping groundwater from shallow aquifers, recycling drainage water, changes to crops and rotations and the adoption of improved irrigation systems. The purpose of this study was to analyse the agricultural benefits of a surface drainage scheme proposed for an Irrigation District in the Murrumbidgee Valley. The objective of the analysis... |
| Tipo: Journal Article |
Palavras-chave: Land Economics/Use. |
| Ano: 1992 |
URL: http://purl.umn.edu/7423 |
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| Jones, Randall E.; Cacho, Oscar J.; Sinden, Jack A.. |
| An appropriate economic framework for valuing the benefits of weed management technologies is to treat weeds as a renewable resource stock problem. Consequently, the weed seed bank is defined as a renewable resource that changes through time due to management and seasonal conditions. The goal of decision-makers is to manage this (negative) resource so as to maximise returns over some pre-specified period of time. A modelling framework is presented for evaluating the biological and economic effects of weed management. The framework includes population dynamics, water balance, crop growth, pasture growth and crop/pasture rotation models for measuring the physical interactions between weeds and the environment. These models link in with numerical optimal... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Weeds; Modelling; Dynamic analysis.; Land Economics/Use. |
| Ano: 2003 |
URL: http://purl.umn.edu/57902 |
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| Marshall, Graham R.; Jones, Randall E.. |
| The whole farm financial effects of laser land forming were analysed using a two stage modelling procedure. In the first stage, linear programming models of representative Murrumbidgee Irrigation Area (MIA) rice farms were used to predict the profit-maximising activity mixes with and without successive increments of land forming. In the second stage, the profit-maximising activity mixes with and without an increment became inputs into a spreadsheet model designed to undertake discounted cash flow analysis of investment in the increment. The transition over time of yields to the achievable levels for land formed layouts was accounted for in the spreadsheet model, as were the effects of taxation (including taxation concessions for land forming) and access to... |
| Tipo: Journal Article |
Palavras-chave: Farm Management. |
| Ano: 1993 |
URL: http://purl.umn.edu/10323 |
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| Marshall, Graham R.; Jones, Randall E.; Wall, Lisa M.. |
| When assessing farming strategies, it is important to account for the opportunities provided for tactically adjusting to outcomes of risk. The hypothesis that accounting for tactical adjustment is more important than accounting for risk attitude was supported in this study with regard to identifying the optimal drainage recirculation strategy for an irrigated dairy farm. Failing to account for tactical adjustment would lead to a sub‐optimal choice, costing the farmer about A$3 100 in present value terms. In contrast, failing to account for risk aversion would not affect the strategy chosen. The distribution method was found to be well suited to modelling tactical adjustment. |
| Tipo: Journal Article |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 1997 |
URL: http://purl.umn.edu/118064 |
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| Hoque, Ziaul; Farquharson, Robert J.; Taylor, Ian; Walker, Steve; Osten, Vikki; Jones, Randall E.. |
| Economic losses and costs associated with weeds in dryland cotton production are important, both for growers and for industry bodies when making decisions about research priorities and research and development funding. A survey was conducted to provide information on weed types, control strategies and estimated costs to growers. We used information from the survey to estimate conventional financial losses due to weeds, and as a basis for evaluating aggregate economic (society) impacts. An economic surplus model was used to estimate the aggregate societal impact of weeds for three production regions in north-eastern Australia. The annual economic costs associated with weeds were estimated to be $41 million, and the on-farm financial costs were $25 million.... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Weeds; Dryland Cotton; And Economics; Crop Production/Industries; Environmental Economics and Policy. |
| Ano: 2003 |
URL: http://purl.umn.edu/57893 |
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| Registros recuperados: 22 | |
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