View
219
Download
0
Category
Tags:
Preview:
Citation preview
Ver 2001 (c) 2001, Purdue University 1
Transgenic Crops in Indiana
Bob NielsenPurdue University
Email: rnielsen@purdue.eduWeb: http://www.kingcorn.org
On the Web at:http://www.agry.purdue.edu/ext/pdf/Transgenic_Crops-2001.pdf
Ver 2001 (c) 2001, Purdue University 2
Genetic Crop Improvement
The ‘old-fashioned’ way to achieve genetic improvement in corn and soy was through traditional sexual acts among consenting, or sometimes not consenting, plants of the same species.
Ver 2001 (c) 2001, Purdue University 3
‘Natural’ Corn Plant SexPollen produced in the tassel anthers contains the male genetic material.
Ovules produced on the ears contain the female genetic material.
Gravity, wind or human intervention allows the pollen to fertilize the ovules.
This ‘natural’ sex has been going on for thousands of years!
Ver 2001 (c) 2001, Purdue University 4
Results of ‘Natural’ Crop Sex
Domestication of crops. Improved crop traits for
enhanced yield and/or grain quality.
Genetic modification (GM) of crop species by: Rearrangement of genes within a species via
natural or directed-pollination Incorporation of genes from “wild” or “close”
relatives via natural cross-pollinationImage Source: USDA, Image Number K7743-13http://www.ars.usda.gov/is/graphics/photos/
Ver 2001 (c) 2001, Purdue University 5
‘Natural’ GM of Crops Works!
Indiana corn grain yields have increased by 1.6 bushels per acre per year for the last 70 years.
Primarily due to ‘natural’ genetic modification (GM) and improved crop production technologies.
Ver 2001 (c) 2001, Purdue University 6
But, some worry… The annual yield gain (1.6 bu/ac/yr) as a
percent of the yield potential of the corn crop has been decreasing for the past 70 years.
Nagging Question:Can we keep up with the increasing global need for food?
Ver 2001 (c) 2001, Purdue University 7
Limits to Crop Breeding? Slow process to develop new varieties.
Not uncommon for 8 – 10 years from start to finish using traditional breeding techniques.
Desired new or improved traits not always present in crop species. Disease or insect resistance Physiological improvements Stress tolerance Grain or plant composition
Ver 2001 (c) 2001, Purdue University 8
Thus, Genetic Engineering Allows for faster variety development.
Tissue culture, recombinant DNA, etc. Allows for transferring heretofore
unavailable genetic traits into a crop variety from unrelated species. e.g., transgenic traits such as Bt insect
resistance originating from soil bacteria.
Ver 2001 (c) 2001, Purdue University 9
Transgenic Example: Bt Bt genes originate from the soil bacteria,
Bacillus thuringiensis Researchers can identify and isolate the genes. “Blasted” into corn DNA using gold particle
gene guns Bt genes that successfully
incorporate into corn DNA express the insecticidal Bt protein in corn plant grown by farmer.
Image Source: Univ. of Nebraskahttp://www.agbiosafety.unl.edu/education/summary.htm
Ver 2001 (c) 2001, Purdue University 10
Genes vs. Events Different versions of a gene may exist.
Cry1a(b), Cry1a(c), Cry9c, etc. for Bt genes. Thus, different varieties marketed.
The combination of exact gene version and its eventual location within the corn genome is termed an ‘event’. Two companies may use the same
Bt gene, but located in different DNA positions; thus two different ‘events’.
Image Source: Univ. of Nebraskahttp://www.agbiosafety.unl.edu/education/transformation.htm
Ver 2001 (c) 2001, Purdue University 11
So, what about StarLink™?
StarLink™ corn hybrids contained the Cry9C insecticidal gene from Bacillus thuringiensis Technically, is a different version of
the Bt gene, but has the same mode of action as other Bt genes
However, the protein has different binding site in the insect gut than that from other Bt versions, which made it attractive for combating insect resistance to Bt.
Ver 2001 (c) 2001, Purdue University 12
Common consumer concerns?
Fears of unidentified food safety risks from transgenic modifications Toxins Carcinogens Dietary preferences
Not a risk, but a matter of choice Allergens
Soybean & Brazil nut genes Kraft™ taco shell recall & StarLink™ Bt corn
Ver 2001 (c) 2001, Purdue University 13
So, what about StarLink™?
Stability of protein to heat and gastric digestion are greater than those of other Bt genes Was the reason for allergen
uncertainty on the behalf of EPA regulators
Was the reason for non-approval of StarLink™ corn for human food use.
Ver 2001 (c) 2001, Purdue University 14
Common consumer concerns?
Fears of unidentified environmental risks from transgenic modifications Off-target injury or death to nonpests
Monarch butterflies & Bt corn pollen Genetic selection pressure for resistance to
transgenic trait or herbicide used with transgenic trait
Glyphosate (Roundup™) & ryegrass in Australia Gene escapes (cross-pollination) to weedy
relatives of crops Canola (rapeseed) & weedy mustards in Canada Corn & wild relatives in Mexico
Ver 2001 (c) 2001, Purdue University 15
Common consumer concerns?
Fears of corporate monopolies in agricultural production Control of global food
supply Elimination of small
farmers
Top 7 Agrochemical Co's
5.9
3.9
3.7
2.5
2.3
2.3
2.2
2000 sales ($ billion)
Ver 2001 (c) 2001, Purdue University 16
Marketplace response? Grain importers, buyers & processors have
responded to consumer concerns by limiting which transgenic varieties they will purchase. European Union has an accepted list
Includes Roundup Ready® soy & most Bt corn, but not Roundup Ready® corn or StarLink™ Bt corn
Acceptance by processors & public is less certain for the immediate future
Frito-Lay, Gerber, Staley, McDonalds, National Starch Kraft (taco shell recall)
Ver 2001 (c) 2001, Purdue University 17
Transgenic Crops in Indiana Herbicide tolerant varieties
Glyphosate resistant soy & corn Roundup Ready®
Glufosinate-ammonium resistant corn Liberty Link®
Insect resistant varieties Bt corn
Primarily European corn borer control Several Bt genes and events marketed
Ver 2001 (c) 2001, Purdue University 18
Transgenic Corn in U.S.
6%
6%
0%
5%
10%
15%
20%
25%
30%
35%
40%
NE IA IL IN OH U.S.
Perc
ent
of co
rn a
cres
StackedHTBt
2001 Crop Year
Source: USDA-NASS, June 2001, on the Web at: http://usda.mannlib.cornell.edu/reports/nassr/field/pcp-bba/acrg0601.txt
Ver 2001 (c) 2001, Purdue University 19
Transgenic Soy in U.S.
78%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
NE IA IL IN OH U.S.
Perc
ent
of so
y a
cres
HT
2001 Crop Year
Source: USDA-NASS, June 2001, on the Web at: http://usda.mannlib.cornell.edu/reports/nassr/field/pcp-bba/acrg0601.txt
Ver 2001 (c) 2001, Purdue University 20
Issues for Indiana Farmers Seed cost of TG crops?
Typically more expensive than non-TGs Agronomic benefits of TG crops?
Sometimes questionable Agronomic disadvantages of TG crops?
Sometimes ignored Market uncertainties of TG crops?
Sometimes dramatic TG consequence for non-TG crops?
Can be costly
Ver 2001 (c) 2001, Purdue University 21
Grow TG crops or not? Must determine the balance between
agronomic costs, agronomic or economic benefits and market uncertainties
High cost + some benefit + feed own livestock = little economic risk
For example:High cost + little benefit + uncertain market = substantial economic risk
Ver 2001 (c) 2001, Purdue University 22
TG crops as agronomic inputs
Nielsen’s Opinion: Insect-resistant or
herbicide-tolerant varieties are NOT CRITICAL for the successful production of corn & soybean in Indiana!
In other words, growing non-TGs will not result in economic ruin for most Indiana farmers!
Ver 2001 (c) 2001, Purdue University 23
Example: Bt corn
An “insurance” trait The Bt gene or trait, by
itself, does not increase yield Only useful when pest occurs
Little payback in years when European corn borer (ECB) infestations are minor
For example, 1998 & 1999 in Indiana ECB damage in 2000 and 2001 more severe,
but damage still questionable economically.
Image Source: USDA, Image Number K2634-8http://www.ars.usda.gov/is/graphics/photos/
Ver 2001 (c) 2001, Purdue University 24
Our position on Bt corn … Bt corn is not economical for the
average Indiana corn field due to low historical frequencies and severities of ECB outbreaks relative to “tech fees” of hybrids (Purdue Extension Publication ID-219)
25%
12%6% 7%
24%
NE IA IL IN OH
More <<<<<<< ECB Pressure >>>>>>> Less
Bt acreage, 2001
Ver 2001 (c) 2001, Purdue University 25
So, what about RR soy? Why so popular?
Good weed control Lower herbicide
cost For many farmers
More time flexibility
Less crop injury Less mgmt. effort
Any disadvantages? Higher seed cost Appl’n timing
Some wait too long to apply herbicide and consequently suffer yield loss to early weed pressure
Market acceptance?
Sometimes an issue
Genetic yield diff.?
76%
73%
64% 78%
64%
NE IA IL IN OH
RR soy acreage, 2001
Ver 2001 (c) 2001, Purdue University 26
TG Consequences for non-TG
Because some grain buyers will not accept TG grain, some farmers need to take extra precautions to avoid TG contamination of their non-TG grain. TRANSLATION: Extra costs and
headaches placed on farmers and the grain buying industry.
Ver 2001 (c) 2001, Purdue University 27
Costs of non-TG production
Ensuring seeding purity Seed source certification for non-TG Prior crop in the field Planting operation
Avoiding cross-pollination w/ TGs (corn) TGs or not in adjacent fields Buffer rows around edges of field Tinkering w/ planting date to manipulate
timing of pollination of corn relative to adj. fields
Ver 2001 (c) 2001, Purdue University 28
Costs of non-TG production
Ensuring harvesting purity Super cleanout of harvester prior to harvest
of non-TG field Harvest non-TG fields before TG fields
Avoiding grain commingling Super cleanout of storage facilities
Store TG separate from non-TG Super cleanout of transport equipment Consider selling or delivering grain directly
from field harvest
Ver 2001 (c) 2001, Purdue University 29
StarLink™ lessons for future
Biotech firms should not be allowed to market a biotech variety until: The variety has been approved by regulatory
agencies and accepted by the grain industry for all end uses, including feed, industrial, food and pharmaceutical;
Thoughts courtesy of:
Dirk Maier, Purdue Ag. Engr.
Thoughts courtesy of:
Dirk Maier, Purdue Ag. Engr.
Ver 2001 (c) 2001, Purdue University 30
StarLink™ lessons for future
Biotech firms should not be allowed to market a biotech variety until:
The variety has been approved by regulatory agencies and accepted by the grain industry for all end uses, including feed, industrial, food and pharmaceutical;
Reliable and inexpensive testing technology is available for use at the first point of sale (such as strip-test kits for elevator use);
Case in Point:
Roundup Ready® corn, 2001 harvest season, test kits available (as of 10/8/01) for new NK603 event (lesser acreage) but not older GA21 event (greater acreage).
Case in Point:
Roundup Ready® corn, 2001 harvest season, test kits available (as of 10/8/01) for new NK603 event (lesser acreage) but not older GA21 event (greater acreage).
Ver 2001 (c) 2001, Purdue University 31
StarLink™ lessons for future
Biotech firms should not be allowed to market a biotech variety until:
The variety has been approved by regulatory agencies and accepted by the grain industry for all end uses, including feed, industrial, food and pharmaceutical;
Reliable and inexpensive testing technology is available for use at the first point of sale (such as strip-test kits for elevator use); and
Tolerance levels based on detectable limits have been established in order to give the U.S. grain handling, exporting and processing industry the ability to meet customer demands with respect to the presence of approved but undesired transgenic crop traits in their end-products.
Ver 2001 (c) 2001, Purdue University 32
Bottom Line … The “GMO” debate will continue into the
near future. Current TGs are not critical for the
agronomic success of most Indiana corn/soy operations.
Farmer’s choice to grow or not depends primarily on his/her perception of the agronomic benefits of the TG, the market uncertainties for TGs in the coming crop year & seed availability of non-TG varieties.
Ver 2001 (c) 2001, Purdue University 33
References Hyde, J., M.A. Martin, P.V. Preckel, C. R. Edwards. 1998. The
Economics of Bt Corn: Implications for Adoption. Purdue Ext. pub ID-219. On the Web at: http://www.agcom.purdue.edu/AgCom/Pubs/ID/ID-219.pdf
Nielsen, Bob. 2001. Biotechnology Issues on the Web. On the Web at: http://www.kingcorn.org/cafe/biotech.html
Nielsen, Bob. 2001. Silk Emergence. On the Web at: http://www.kingcorn.org/news/articles.01/Silks-0626.html
Nielsen, Bob. 2001. Tassel Emergence & Pollen Shed. On the Web at:http://www.kingcorn.org/news/articles.01/Tassels-0626.html
Nielsen, Bob and Dirk Maier. 2001. GMO Issues Facing Indiana Farmers in 2001. On the Web at: http://www.agcom.purdue.edu/AgCom/Pubs/GQ/GQ-46.pdf
Univ. of Nebraska-Lincoln. 2001. AgBiosafety. On the Web at: http://www.agbiosafety.unl.edu/
Recommended