Five projects of varying size and complexity were pursued related to economic aspects of biodiesel and oilseed production in the Willamette Valley. Each area is summarized below with links to additional information and sources.
- Willamette Valley Agricultural Model
- Meal Market Size
- Biodiesel Private and Social Cost Estimates
- Oilseed Crop and Biodiesel Production Cost Estimator Tools
- Specialty Seed Producers' Concerns Regarding Canola Production
1. Willamette Valley Agricultural Model
Model Overview: The purpose of the Willamette Valley Agricultural Model is to understand the possible effects of subsidies on the composition of the Willamette Valley’s agricultural system in the aggregate and by general land/soil categories. A nonlinear mathematical programming model of the Willamette Valley’s agricultural system is constructed to account for 17 major soil types, 19 major crops, irrigated/non-irrigated production options, 11 crop rotations, and 3 major regions. Oilseeds are assumed to serve as rotations for other crops. Estimates of yield differentials over soil types, transportation costs by region, costs by soil types, yield-based costs, and prices (endogenous & exogenous), are major determinants in the model. Programmatic constraints include contract limits for certain crops and feasible crop rotations. Land use constraints by region, soil type, and irrigation availability are derived using a Geographic Information System (GIS) developed by the author drawing upon multiple sources. The model is programmed to run using GAMS (General Algebraic Modeling System).
Thesis Findings: The study finds that 2008 oilseed subsidies (and 2005-2007 average commodity prices) are sufficient to induce oilseed production (approximately 240 million pounds total) on about 75 thousand acres, or about 7% of total the Willamette Valley’s land devoted to the production of its major and relatively easily interchangeable crops. Iterations of the model demonstrate that fallow and wheat acres are the first to decline due to increased oilseed production and that there is minimal change in terms of crops shifting from being grown on one general soil class to another. If flax and camelina can be grown for two years in a row before needing a year’s rotation, production levels would double given current subsidies and land use changes would be more dramatic. The model developed as a result of this research effort has the potential to be modified and used for future studies.
Documentation: Once Mr. Siegel’s thesis was completed, it was recognized that the WVAM may be used by others to simulate other scenarios and gain further insight. All of the relevant files were consolidated into one place to aid in this process. This document will explain how to use all of these files in order to parameterize, run, and analyze results from, the WVAM. Readers will not find a thorough explanation of data sources and methodology—Mr. Siegel’s thesis is recommended for this purpose. Furthermore, it is assumed that users of the model are already familiar with the GAMS and that the model is used for educational or non-profit reasons.
2. Meal Market Size
A cursory analysis explored the size of the DDGS and Canola potential markets to begin to explore how large the oilseed to biodiesel market can become while still taking advantage of co-product credits. Dhuyvetter, et al.’s paper is recommended for this purpose since it is the most transparent about its assumptions and is the most straightforward in estimating the size of the potential DDGS for feed market in the United States. The same structure was then used, in concert with local poultry and dairy experts, to estimate the size of the Canola for feed meal market. Dhuyvetter et al finds that the size of the national market for DDGS for feed is approximately 56.1 million metric tons, which translates into approximately 19 billion gallons of ethanol (assuming 2.7 gallons of ethanol per bushel of corn and 17.4 pounds of DDGS per bushel of corn). Using the same structure as Dhuyvetter with daily intake values for Canola we find that the national potential market is maxed at approximately 38.7 million metric tons or 5.1 billion gallons of biodiesel (assuming 35% oil content and 90% extraction efficiency). Assuming higher oil yields and hexane-extraction levels of efficiency, 40% and 99% respectively, the 38.7 million metric tons translates into 7.3 billion gallons. For the area around Oregon (Oregon, Washington, Idaho, California) the market for DDGS and Canola meal for feed is estimated to be 4.10 and 4.13 million metric tons, or 1,700 and 550 million gallons of ethanol and biodiesel, respectively. (The previous numbers assume 35% oil content and 90% extraction efficiency.) It is important to note, however that no assessment of export markets has been conducted. Such markets could indeed have significant local impact. Cascade Grain in NW Oregon, for example, was structured with exports as a business component.
Meal Market Size, Statistical Sources:
Papers referencing co-product market size in the US:
- 36.5 million metric tons (based on Cooper & Distiller Grains Feeding Recommendations) – Eidman, V.R. (2007) Economic Parameters for Corn Ethanol and Biodiesel Production. Journal of Agricultural and Applied Economics, Volume 39 (2) http://purl.umn.edu/6519
- 40 million metric tons (refer to Cooper) – Schilcher, M. (2000). Biofuels in the US: Today and in the Future. The Journal of Agrobiotechnology Management & Economics. Volume 11 (1) Article 1. http://www.agbioforum.org/v11n1/v11n1a01-schlicher.htm,
- 13.7 to 40.3 million metric tons depending on lower or upper limit inclusion level (use AU dataset) – Cooper, G. (2006). A Brief, Encouraging Look at ‘Theoretical’ Distillers Grains Markets. Distiller Grains Quarterly. http://distillersgrainquarterly.com/article.jsp?article_id=1176&article_title=A+Brief%2C+Encouraging+Look+at+%3FTheoretical%3F+Distillers+Grains+Markets
- 56.1 million metric tons (they refer to Dhuvetter, et al) – Kenkel, P. & R.B. Holcomb. Challenges to Producer Ownership of Ethanol and Biodiesel Production Facilities. Journal of Agricultural and Applied Economics, 38,2 (August 2006) 369-375. http://ageconsearch.umn.edu/handle/43772
- 56.1 million metric tons (51.5 million short tons) (used animal count dataset) - Dhuyvetter, K.C., T. L. Kastens, & M. Boland. (2005). The U.S. Ethanol Industry: Where will it be located in the future? Agricultural Issues Center, University of California. http://www.agmanager.net/agribus/energy/Ethanol%20Industry(AgMRC)--11.25.05.pdf
Other Related Papers:
- Examining the scale of Canola meal production in Australia. This may be a paper to emulate in terms of their approach to the size of the market. They use a large-scale linear programming feed optimization program. – Brennan, J.P. & R.P. Singh, I.P. Singh. (1999). Role of Canola Meal in Livestock Feed in Australia. Rapeseed Congress, Canberra, Australia, 1999. http://regional.org.au/au/gcirc/1/247.htm
- Similar paper but more comprehensive to “Role of Canola Meal in Livestock Feed in Australia”. Includes feeding rate assumptions for several animals. – Brennan, J.P. & R.P. Singh. (2000). Economic Assessment of Improving Nutritional Characteristics of Feed Grains. Economic research Report No 3. http://ageconsearch.umn.edu/bitstream/28000/1/er000003.pdf
- Paper on uses for Canola meal (for feed, soil amendments etc.), includes value for soil amendment at 100$/ton. Useful references. – Bonnardeaux, J. (2007). Uses for Canola Meal. Department of Agriculture and Food, Western Australia. http://www.agric.wa.gov.au/content/sust/biofuel/Usesforcanolameal_report.pdf
Corn-to-Ethanol Energy Use
- Similar paper to one below. Just updated. – Shapouri, H., J.A. Duffield, M. Wang. (2003). The Energy Balance of Corn Ethanol Revisited. Transactions of the ASAE. Vol. 46(4): 959–968.
- Useful break-down wet vs. dry, with sources, for various energy sources – Shapouri, H., J.A. Duffield, M. Wang. (2002). The Energy Balance of Corn Ethanol: An Update. Agricultural Economic Report No. 814. http://ageconsearch.umn.edu/handle/34075
- Wet vs. Dry: corn production (various), corn transport (GREET model), eth. conversion (BBI Intnl. industry survey), eth. distribution (GREET model) – See Table 6
- Paper detailing energy use for converting corn into ethanol. Their breakdown includes differentiation between wet and dry mill. – Lorenz, D. & D. Morris. (1995). How Much Energy Does it Take to Make a Gallon of Ethanol. Institute for Local-Self Reliance (ILSR). http://www.usask.ca/agriculture/caedac/PDF/netethan.PDF
- Paper which includes various estimates for Corn Ethanol production process energy use over time (page 71). – Wang, M. (1999). GREET 1.5a - transportation fuel-cycle model. Illinois USA: Argonne National Laboratory. http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=14775
- Referenced by Wang 1999 above. This paper includes a summary of other estimates for BTU/gall in the 90s for wet & dry processes. It also includes its own numbers. While it does not break energy consumption down by stage, etc. it does have a diagram describing the process flow for their wet mill vs dry mill. – Wang, M.Q., et al., (1997). Fuel Ethanol Produced from U.S. Midwest Corn, prepared by Center for Transportation Research, Argonne National Laboratory, Argonne, Ill., for Illinois Department of Commerce and Community Affairs, Springfield, Ill., Dec. 19. http://www.transportation.anl.gov/pdfs/TA/141.pdf
- Useful paper summarizing results from the Renewable Fuels Association (RFA). Contains data on overall energy use (by type), yields, and CO2 capture. Wu, M. (2007). Analysis of the Efficiency of the U.S. Ethanol Industry 2007. Argonne National Laboratory. http://www1.eere.energy.gov/biomass/pdfs/anl_ethanol_analysis_2007.pdf
Oilseed-to-Biodiesel Energy Use
- Kallivroussis, L., A. Natsis, & G. Papadakis. The Energy Balance of Sunflower Production for Biodiesel in Greece. Biosystems Engineering (2002) 81 (3), 347–354.
- Paper looking at various policy aspects of biodiesel. Includes summary of various energy input studies. – Frondel, M., J. Peters. (2007). Biodiesel : A New Oildorado? Energy Policy 35 (2007) 1675–1684.
- Janulis, P. (2004). Reduction of energy consumption in biodiesel fuel life cycle. Renewable Energy 29 (2004) 861–871
- USDA & USDoE. (1998). An Overview of Biodiesel and Petroleum Diesel Life Cycles. http://www.nrel.gov/docs/legosti/fy98/24772.pdf
3. Biodiesel Private and Social Cost Estimates
This study assesses the economic potential of biodiesel production in the Willamette Valley for six oilseeds as potential feedstocks: canola, flax, camelina, yellow mustard, sunflower, and safflower. We evaluate costs and returns from feedstock production, oilseed crushing, and biodiesel processing. Our analysis is based on the best available information (available towards the end of 2008) on cost of production, yield, other technical parameters, market prices, and government subsidies and tax credits. The study evaluates the economic assessments in terms of current costs and returns excluding subsidies; costs and returns including subsidies; and, finally, in terms of the full “social cost” of production. Costs for the production of biodiesel at a small-scale (0.5 million gallons per year) are found to range between $5.82 to $12.94 per gallon depending on the feedstock.
Other Papers on the Policy Aspects of Biodiesel & Biofuels in General
- Tyner, W.E. & F. Taheripour. (2007). Renewable Energy Policy Alternatives for the Future. American journal of agricultural economics, 2007 Dec., v. 89, no. 5, p. 1303-1310.
- De La Torre Ugarte, D.G., B.C. English, & K. Jensen. (2007). Sixty Billion Gallons by 2030: Economic and Agricultural Impacts of Ethanol and Biodiesel Expansion. Amer. J. Agr. Econ. 89 (Number 5, 2007): 1290–1295
- Korbitz, W. (1999). Biodiesel production in Europe and North America, an encouraging prospect. Renewable Energy, Volume 16, Number 1, 4 January 1999 , pp. 1078-1083(6)
- Paper looking at biofuels, subsidies, and policy implications. – Steenblik, R. (2007). Subsidies: The Distorted Economics of Biofuels. Discussion Paper No. 2007-3. The Global Subsidies Initiative, International Institute for Sustainable Development, Geneva, Switzerland. http://oberon.sourceoecd.org/vl=8781987/cl=19/nw=1/rpsv/workingpapers/20708270/wp_5kzbxt6v057g.htm alternatively: http://www.internationaltransportforum.org/jtrc/DiscussionPapers/DiscussionPaper3.pdf
- World bank paper reviewing literature of biofuels and making research recommendations. Deepak, R. & D. Zilberman. (2007). Review of environmental, economic and policy aspects of biofuels. Policy Research working paper ; no. WPS 4341. http://econ.worldbank.org/external/default/main?pagePK=64165259&theSitePK=469372&piPK=64165421&menuPK=64166093&entityID=000158349_20070904162607
- Interesting paper looking at optimal scale of ethanol plants. Heavy on the theory side. Gallagher, P., H. Shapouri, & H. Brubaker. (2007). Scale, Organization, and Profitability of Ethanol Processing. Canadian Journal of Agricultural Economics 55 (2007) 63–81.
- Production costs for making Ethanol. Shapouri, H. & P. Gallagher. (2002). USDA’s 2002 Ethanol Cost of Production Survey. Office of Energy Policy and New Uses, USDA. http://www.usda.gov/oce/reports/energy/USDA_2002_ETHANOL.pdf
- Interesting paper looking at the research thus far on energy balance for ethanol from biomass and introduced new approach which takes the whole life cycle into account, including the performance of the fuels, relative to gasoline. Gnansounou, E., & A. Dauriat. (2005) Energy Balance of Bioethanol: A Synthesis. European Biomass Conference and Exhibition. http://www.eners.ch/downloads/eners_0510_ebce_paper.pdf
- Interesting paper on the effects of market power on capturing the subsidy. Saitone, T.L., R.J. Sexton, & S.E. Sexton. (2007). The Effects of Market Power on the Size and Distribution of Benefits from the Ethanol Subsidy. Agricultural Issues Center, August 2007, University of California. http://aic.ucdavis.edu/publications/MarketPowerAndEthanolSubsidy.pdf
- Hill, J. E. Nelson, D. Tilman, S. Polasky, D. Tiffany. (2006). Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels. PNAS, July 25, 2006, vol. 103 no. 30. http://www.pnas.org/content/103/30/11206.abstract
- Farrell, A.E., R.J. Plevin, B.T. Turner, A.D. Jones, M.O’hare, & D.M. Kammen. (2006). Ethanol Can Contribute to Energy and Environmental Goals. Science 27 January 2006, Vol. 311. no. 5760, pp. 506 - 508 http://www.sciencemag.org/cgi/content/abstract/311/5760/506
- A paper looking at the costs of biofuels related to their objectives. Then it examines what objectives might actually be implied by the biofuel subsidies and finds that farm income support is one. They look into things a bit deeper…. “Implied Objectives of U.S. Biofuel Subsidies” http://purl.umn.edu/6333
- Interesting paper looking at limits to biodiesel industry. “Understanding U.S. Biodiesel Industry Growth using System Dynamics Modeling” http://www.sys.virginia.edu/sieds06/papers/FMorningSession8.2.pdf
- Interesting paper, with new estimates of biodiesel production costs (lower than what we estimated at OSU previously): “The Growth and Direction of the Biodiesel Industry in the U.S.” http://ageconsearch.umn.edu/bitstream/21402/1/sp06gi02.pdf
- This paper has some useful details like Net energy gain, maintenance, and total digestible nutrients. “Structure of the Canola and Biodiesel Industries” http://ageconsearch.umn.edu/bitstream/7644/1/aer606.pdf
- Paper looking at relationship between oil prices and vegetable oil prices. It appears to find a minimal relationship. “Examining the Evolving Correspondence Between Petroleum Prices and Agricultural Commodity Prices” http://purl.umn.edu/9881
- Very worthwhile to read paper looking again at some of the general equilibrium models to take into account the fact that biofuels from corn and biodiesel have co-products. http://purl.umn.edu/6452
- Important paper to have handy. ERS’ analysis. – Ash, M. & E. Dohlman. (2008) Oil Crops Outlook. USDA ERS. http://usda.mannlib.cornell.edu/MannUsda/viewDocumentInfo.do?documentID=1288
- Interesting paper. – Johnson, D.D., & V. Satyanarayana, B.L. Dahl, F.J. Dooley. (1996) Trade in Minor Oilseeds: A Spatial Equilibrium Analysis of Sunflower and Canola. Agricultural Economics Report No. 353. https://www.agecon.purdue.edu/cab/research/articles/minoroilseeds.pdf
4. Oilseed Crop and Biodiesel Production Cost Estimator Tools
The first decade of the 21st century has witnessed great variability in terms of agricultural commodity and input prices. Two tools were developed in order to be able to conduct an on-the-fly analysis of the feasibility of oilseed crop production as well as vegetable oil and biodiesel processing given various parameters (e.g. fertilizer prices, crop yields, electricity costs, etc.).
Oilseed Enterprise Budget Comparison Tool: The purpose of the oilseed enterprise budget comparison tool is to assist with the decision making process that a grower in Oregon might face when considering to grow his or her own oilseeds for biodiesel production. The first step in this process naturally involves the decision to grow oilseeds. This spreadsheet assists the grower to evaluate his or her options in this regard. The workbook has been designed to conduct relatively rigorous comparisons between the estimated cost of growing a variety of oilseeds to other crops conventionally grown in the Willamette Valley in Oregon. Crops include: canola, flaxseed, camelina, winter wheat, annual ryegrass, perennial ryegrass, tall fescue, and crimson clover. The default values are drawn from hypothetical (for oilseed crops) and actual enterprise budgets developed by teams of agronomists at Oregon State University. The enterprise budgets were created using the Mississippi State Budget Generator (MSBG). The MSBG allows one to edit all parameters and ensure full comparability (accross variable and fixed costs). It was recognized, however, that a simpler tool was needed. This workbook was developed in response. It allows for comparability accross variable cost estimates and permits the user substantial control over the parameters. It does not, however, allow for detailed comparisons of fixed costs since it does not incorporate practices.
Small-Scale Oilseed to Biodiesel Cost Estimator: The purpose of the biofuel cost estimator is to assist with the decision-making process that a grower in Oregon might face when considering to produce his or her own biofuel. The workbook has been designed to estimate the costs associated with extracting oil from oilseeds and subsequently processing the oil into biodiesel. The default values should not be regarded as authoritative in any way. Instead, they are estimates based on limited data available to the designer of this tool. The tool is split up into three distinct worksheets where the user can enter unique parameters to see how the final cost of biodiesel looks.
5. Specialty Seed Producers' Concerns Regarding Canola Production
As the world seeks out renewable sources of energy it has seen a major increase in the production of biodiesel and the raw materials it requires. Within that context, Oregon has turned its attention to Canola, the oil of which can be used as a basic raw material for the production of biodiesel. As soon as investigations commenced regarding the profitability and agronomic viability of Canola in Oregon reactions quickly came from the specialty seed industry. Since much of the specialty seed industry’s vegetables belong to the same genus as Canola (Brassica), if the crops are in close proximity, the genes of one may carry over into another. This investigation examines the concerns regarding the adverse effect that Canola production may have on the specialty seed industry in Oregon (potential mechanisms) and the argument that Canola has had a deleterious effect on specialty seed production elsewhere (historical cases). Findings include that it can be safely stated that there are historical, although very recent and limited, cases demonstrating the negative effect Canola may have on the specialty seed industry. Overall, interviews point to four areas as having had a decrease in specialty seed production due to Canola, all within the last fifteen years: Arizona (reason: lack of coordination), France (reason: pollen beetle), Italy, Denmark (reason: volunteer control). The investigation also finds, however, that there is a long list of concerns specialty seed producers have regarding how Canola may negatively impact specialty seed production. Five key highly interrelated aspects were mentioned: the need for a system and willingness to coordinate/collaborate in the face of differing crop approaches; volunteers, weeds, and oilseed persistence; monoculture & pest or disease effects; GMO out crossing. Of special significance is the sensitivity that Japanese and European purchasers have regarding GM traits in imports and the importance of coordination/cooperation between specialty seed growers and Canola growers to ensure safe distances between fields and appropriate field practices are conducted avoid volunteers, etc.
Seed & Other Relevant Agricultural Websites:
Commodity, including Seed, Data Websites:
Commodity Data:
Related Papers on Biological/Ecological Aspects:
- Andow, D.A., & C. Zwahlen. (2005). Assessing environmental risks of transgenic plants. Ecology Letters, Volume 9 Issue 2, Pages 196 – 214. http://www3.interscience.wiley.com/journal/118634037/abstract
- Andow, D.A., C. Zwahlen. (2006). Assessing environmental risks of transgenic plants. Ecology Letters, Volume 9, Number 2, February 2006 , pp. 196-214(19). http://www.ingentaconnect.com/content/bsc/ele/2006/00000009/00000002/art00013
- Aono, M., S. Wakiyama, M. Nagatsu, N. Nakajima, M. Tamaoki, A. Kubo, H. Saji. (2006). Detection of feral transgenic oilseed rape with multiple-herbicide resistance in Japan. Environ Biosafety Res. 2006 Apr-Jun; 5(2):77-87. Epub 2006 Dec 8. http://www.ncbi.nlm.nih.gov/pubmed/17328854
- Beckie HJ (2007) Beneficial Management Practices to Combat Herbicide-resistant Grass Weeds in the Northern Great Plains. Weed Technology: Vol. 21, No. 2 pp. 290–299. http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1614%2FWT-06-083.1
- Beckie HJ, G. Séguin-Swartz, H. Nair, S.I. Warwick, & E. Johnson. (2004). Multiple herbicide–resistant canola can be controlled by alternative herbicides. Weed Science: Vol. 52, No. 1 pp. 152–157. http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1614%2FP2002-163
- Beckie HJ, Leeson JY, Thomas AG, Brenzil CA, Hall LM, et al. (2008) Weed Resistance Monitoring in the Canadian Prairies. Weed Technology: Vol. 22, No. 3 pp. 530–543. http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1614%2FWT-07-175.1
- Beckie, H.J. (2006). Herbicide-Resistant Weeds: Management Tactics and Practices. Weed Technology: Vol. 20, No. 3 pp. 793–814. http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1614%2FWT-05-084R1.1
- Beckie, H.J., S.I. Warwick, H. Nair, G. Seguin-Swartz. (2003). Gene flow in commercial fields of herbicide-resistant canola (Brassica napus) Ecological Applications. Ecol. Appl. Vol. 13, no. 5, pp. 1276-1294. Oct 2003. http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=5764146&q=&uid=793306391&setcookie=yes
- Blackshaw, R.E. (2006). Chapter 6 – Monitoring Genetically Modified Crops in Canada. Genetically Modified Organisms in Crop Production and their Effects on the Environment: Methodologies for Monitoring and the Way Ahead. 18-20 January 2005. Food and Agriculture Organization of the United Nations. ftp://ftp.fao.org/docrep/fao/009/a0802e/a0802e.pdf#page=91
- Bock, A.K, K. Lheureux, M. Libeau-Dulos, H. Nilsagard, E. Rodriguez-Cerezo. (2002). Scenarios for co-existence of genetically modified, conventional and organic crops in European agriculture. European Commission, Joint Research Centre. Report EUR 20394EN. ftp://ftp.jrc.es/pub/EURdoc/eur20394en.pdf
- Brûlé-Babel, A.L., C.J. Willenborg, L.F. Friesen, & R.C. Van Acker. Modeling the Influence of Gene Flow and Selection Pressure on the Frequency of a GE Herbicide-Tolerant Trait in Non-GE Wheat and Wheat Volunteers. Crop Sci 46:1704-1710 (2006). http://crop.scijournals.org/cgi/content/abstract/46/4/1704
- Chandler, S. & J.M. Dunwell. (2008). Gene Flow, Risk Assessment and the Environmental Release of Transgenic Plants. Critical Reviews in Plant Sciences, Volume 27, Issue 1 January 2008 , pages 25 – 49. http://www.informaworld.com/smpp/content~content=a793238082~db=all
- Clark, E.A. (2006). Environmental risks of genetic engineering. Euphytica, Volume 148, Numbers 1-2 / March, 2006. http://www.springerlink.com/content/ln241106gx04p170/
- Damgaard, H., G. Kjellsson, C. Haldrup. (2007). Prediction of the combined effect of various GM contamination sources of seed: A case study of oilseed rape under Danish conditions. Acta Agriculturae Scandinavica, Section B - Plant Soil Science, 57(3) 247-253. http://www.informaworld.com/smpp/content~content=a769551242~db=all
- Devos, Y, D. Reheul, D. De Waele, L. Van Speybroeck. (2006). The interplay between societal concerns and the regulatory frame on GM crops in the European Union. Environ Biosafety Res. 2006 Jul-Sep; 5(3):127-49. Epub 2007 Mar 24. http://www.ncbi.nlm.nih.gov/pubmed/17445510
- Devos, Y., D. Reheul, A.DE Schrijver, F. Cors, W. Moens. (2004). Management of herbicide-tolerant oilseed rape in Europe: a case study on minimizing vertical gene flow. Environ. Biosafety Res. 3 (2004) 135-148. http://www.ebr-journal.org/index.php?option=article&access=doi&doi=10.1051/ebr:2005001
- Downey RK, & H. Beckie. (2002). Isolation Effectiveness in Canola Pedigree Seed Production. Internal Research Report, Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan, S7N 0X2, Canada, 2002, 14 pp.
- Engels, J, A. Ebert, I. Thormann, M. Vicente. (2006). Centres of Crop Diversity and/or Origin, Genetically Modified Crops and Implications for Plant Genetic Resources Conservation. Genetic Resources and Crop Evolution, Volume 53, Number 8, December 2006 , pp. 1675-1688(14). http://www.ingentaconnect.com/content/klu/gres/2006/00000053/00000008/00001215
- Friesen, L.F., A.G. Nelson, & R.C. Van Acker. (2003). Evidence of Contamination of Pedigreed Canola (Brassica Napus) Seedlots in Western Canada with Genetically Engineered Herbicide Resistance Traits. Agronomy Journal 95:1342–1347. http://agron.scijournals.org/cgi/reprint/95/5/1342
- Funk, T. & G. Wenzel, G. Schwarz. (2006) Outcrossing frequencies and distribution of transgenic oilseed rape (Brassica napus L.) in the nearest neighbourhood. Europ. J. Agronomy 24 (2006) 26–34 http://www.botanischergarten.ch/EPOBIO-Brassica/Funk-Outcrossingrates-2006.pdf
- Gaines, T., C. Preston, P. Byrne, W.B. Henry, P. Westra. (2007). Adventitious Presence of Herbicide Resistant Wheat in Certified and Farm-Saved Seed Lots. Crop Sci 47:751-754. http://crop.scijournals.org/cgi/content/abstract/47/2/751
- Halfhill, M.D., J.P. Sutherland, H.S. Moon, G.M. Poppy, S.I. Warwick, A.K. Weissinger, T.W. Rufty, P.L. Raymer, C.N. Stewart Jr. (2005). Growth, productivity, and competitiveness of introgressed weedy Brassica rapa hybrids selected for the presence of Bt cry1Ac and gfp transgenes. Molecular Ecology, Volume 14 Issue 10, Pages 3177 – 3189. http://www3.interscience.wiley.com/journal/118705891/abstract
- Halfhill, M.D., R.J. Millwood, P.L. Raymer, C.N. Stewart, Jr. (2002). Bt-transgenic oilseed rape hybridization with its weedy relative, Brassica rapa. Environ. Biosafety Res. 1 (2002) 19–28. http://www.ebr-journal.org/index.php?option=article&access=standard&Itemid=129&url=/articles/ebr/pdf/2002/01/Halfhill.pdf
- Hall, L., A. Good, H.J. Beckie, & S.I. Warwick. Gene Flow in Herbicide-Resistant Canola (Brassica Napus): The Canadian Experience. Ecological Impact of GMO Dissemination in Agro-Ecosystems. http://www.biosicherheit.de/pdf/dokumente/gmo-dissemination_oecd.pdf#page=57
- Hall, L., K. Topinka, J. Huffman, L. Davis, and A. Good. (2000). Pollen flow between herbicide-resistant Brassica napus is the cause of multiple-resistant B. napus volunteers. Weed Science: Vol. 48, No. 6 pp. 688–694. http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1614%2F0043-1745(2000)048[0688%3APFBHRB]2.0.CO%3B2
- Hall, L.M. & K. Topinka, M. Hartman, A. Good. (2002). Agronomic effects of gene flow: multiple herbicide resistance in volunteer crop plants. The 7th International Symposium on the Biosafety of Genetically Modified Organisms Beijing, China October 10-16. http://saveourseeds.org/downloads/proceedings_BEIJING_oct_2002.pdf#page=47
- Harkera, K. N., G. W. Clayton, R. E. Blackshaw, J. T. O'Donovan, E. N. Johnson, Y. Gan, F. A. Holm, K. L. Sapsford, R. B. Irvine and R. C. Van Acker. (2006). Persistence of Glyphosate-Resistant Canola in Western Canadian Cropping Systems. Agron J 98:107-119 (2006). http://agron.scijournals.org/cgi/content/abstract/98/1/107
- Jorgensen, T., T.P. Hauser, R.K. Jorgensen. (2007). Adventitious presence of other varieties in oilseed rape (Brassica napus) from seed banks and certified seed. Seed Science Research (2007), 17 : 115-125 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1004020
- Knispel AL, McLachlan SM, Van Acker RC, Friesen LF (2008) Gene Flow and Multiple Herbicide Resistance in Escaped Canola Populations. Weed Science: Vol. 56, No. 1 pp. 72–80. http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1614%2FWS-07-097.1
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