The Impact of Genetically Engineered Crops on Farm Sustainability in the United States (2010) / Chapter Skim
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1 Introduction
1 Introduction
Pages 19-58
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From page 19... ...
Similarly, early pastoralists engaged in selective animal breeding. That those practices were recognized as important in the development of ancient human civilizations is apparent in the preservation of instructions on plant breeding in writing, such as in the works of Virgil and Theopastus (Vavilov, 1951)
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From page 20... ...
Hybrid corn varieties, which are developed from crossing different inbred lines, out-yield pure inbred lines, though the seeds produced by hybrid varieties yield poorly. When corn hybrids were first developed, they had no discernible yield advantage over the existing open-pollinated corn varieties of the time (Lewontin, 1990)
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Before the advent of genetic engineering, plant tissue-culture technology expanded the array of available genetic material beyond what was possible with traditional plant breeding by manipulating the fertil ization and embryos of crosses between more distantly related species (Brown and Thorpe, 1995)
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From page 22... ...
Though the three aspects of sustainability often interact with one another, the report organizes each in a separate chapter to facilitate access to the information. The chapter on production economics follows the environmental chapter because many of the economic gains and losses that farmers experience with GE crops result from changes occurring within the farm environment from GE-crop adoption.
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First, social impacts are widely considered to be a necessary element in the definition of sustainability as noted earlier. Second, with the sizable shift in cropping practices and systems to genetic-engineering technology (and the prospect of more GE crops to come)
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4. Human capital and personal values.
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. Just as natural-resource conditions, including pest pressures, vary among fields, farms, and regions, so will the indirect effects on yield and the rate of adoption of GE crops.
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Human Capital and Personal Values Every major study of agricultural-technology adoption has found that at least some aspects of human capital play a role in the process. Fre quently, the more education or experience a farmer has, the more likely he or she is to adopt a new technology.
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It also shows how the factors, up to this point presented as having distinct effects, may influence each other. Examples of potential interactions include the effects of information and social networks on personal values and production inputs and the effect of production-input substitution on productivity.
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GENETICALLY ENGINEERED TRAITS IN CROPS For agricultural crops, the first generation of genetic engineering has targeted traits that increase the efficacy of pest control. Since the introduction of GE crops, new seeds have provided pest control in one or more of three forms: • Herbicide resistance.
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From page 29... ...
The shikimate pathway helps produce aromatic amino acids; it is speculated that glyphosate kills a plant either by reducing aromatic amino acid production and adversely affecting protein synthesis or by increasing carbon flow to the glyphosate-inhibited shikimate pathway, causing carbon shortages in other pathways (Duke and Powles, 2008)
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From page 30... ...
Therefore, the familiarity of the chemicals involved, the size of the market for the seeds of and pesticides for GE crops, and the ease of manipulation of the genes for the traits contributed to HR and IR seeds' being the first GE products to emerge in large-scale agriculture. ADOPTION AND DISTRIBUTION OF GENETICALLY ENGINEERED CROPS Crops with GE traits aimed primarily at pest control have been widely adopted in the United States by farmers of corn, cotton, soybean, canola, and sugar beet and have caused substantial changes in farm-management practices and inputs, such as changes in pesticide use.
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From page 31... ...
. Rates of adoption have been influenced by the type of crop, the trait expressed in the crop, and the pest pressures occurring on the farm.
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SOURCE: USDA-NASS, 2001, 2003, 2005, 2007, 2009b. 54 percent of all soybean acres planted (Table 1-1)
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Minor Crops Widely Planted in Genetically Engineered Varieties by U.S. Farmers Canola.
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. Minor Crops with Genetically Engineered Varieties Not Widely Adopted by U.S.
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INTRODUCTION campaign against GE tomatoes caused some large processors to refuse to purchase the Flavr Savr variety for their products. In response, Calgene tried to sell the variety as a fresh-market tomato, but the vegetable bruised e asily.
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SOURCE: USDA-NASS, 2001, 2003, 2005, 2007, 2009b. 100 80 Percent of soybean acres HR s oy bean 60 40 20 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Year FIGURE 1-4 Herbicide-resistant soybean acreage trends nationwide.
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From page 37... ...
Furthermore, lack of market access for HR corn to the European Union provided an added deterrent against early adoption of HR corn in the late 1990s and early 2000s. TABLE 1-2 Insect Pests of Corn Targeted by Bt Varieties Common Name Latin Binomial Primary Pest Ostrinia nubilalis European corn borer Diatraea grandiosella Southwestern corn borer Diabrotica irgifera irgifera Western corn rootworm Diabrotica barberi Northern corn rootworm Helicoerpa zea Corn earworm Spodoptera frugiperda Fall armyworm Agrotis ipsilon Black cutworm Secondary Pest Diabrotica irgifera zeae Mexican corn rootworm Diatraea crambidoides Southern cornstalk borer Papaipema nebris Stalk borer Elasmopalpus lignosellus Lesser cornstalk borer Diatraea saccharalis Sugarcane borer Richia albicosta Western bean cutworm NOTE: This pest categorization does not describe specific pest pressures in different states or regions.
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From page 38... ...
* 1 2 5 20 37 35 South Dakota 2 3 10 17 21 22 34 43 58 65 Texasa 9 13 20 27 33 Wisconsin 1 1 2 2 2 6 10 22 35 37 Other statesb 1 1 2 2 6 6 10 14 22 28 United States 1 1 2 4 6 9 15 28 40 46 *
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From page 39... ...
INTRODUCTION Herbicide-Resistant Only 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Percent of all corn planted 3 3 3 4 5 6 12 15 15 15 4 6 6 7 8 11 15 17 16 17 5 6 7 8 10 14 14 19 15 15 7 11 15 17 24 30 33 36 30 29 4 7 8 14 14 20 18 22 24 20 7 7 11 15 17 22 29 32 29 24 6 8 6 9 13 12 14 19 21 17 8 8 9 11 13 18 24 23 24 23 39 34 37 34 30 3 4 3 3 4 7 13 12 17 17 11 14 23 24 30 31 32 34 30 25 42 37 37 31 30 4 6 9 9 14 18 18 23 26 27 6 8 12 17 21 19 25 33 32 30 6 7 9 11 14 17 21 24 23 22 All GE Varieties 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Percent of all corn planted 17 16 22 28 33 36 55 74 80 84 11 12 13 16 21 26 40 59 78 79 30 32 41 45 54 60 64 78 84 86 33 38 43 47 54 63 68 82 90 91 12 17 22 35 33 40 44 60 72 75 37 36 44 53 63 66 73 86 88 88 28 32 34 42 49 55 59 62 70 77 34 34 46 52 60 69 76 79 86 91 75 83 88 89 93 9 11 9 9 13 18 26 41 66 67 48 47 66 75 79 83 86 93 95 96 72 77 79 78 84 18 18 26 32 38 46 50 64 75 77 17 20 27 36 46 44 55 67 74 78 25 26 34 40 47 52 61 73 80 85
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From page 40... ...
. European corn borer is a key pest in the western Corn Belt region (Pilcher et al., 2002; Hyde et al., 2003; Mungai et al., 2005)
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From page 41... ...
Thus, GE corn with the Bt trait for corn rootworm control and lower levels of seed-applied insecticide and fungicide substituted for the control tac tics in continuous corn in the 1980s and 1990s of soil-applied insecticides for rootworm control and seed-applied products with higher toxicity 3 for secondary pest control, which growers had to manually apply to the seed. In-plant resistance for rootworm control with low levels of insecticide already applied to the seed by professional seed handlers for control of secondary corn pests is safer for the farmers who plant the crops and for the environment.
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From page 42... ...
SOURCE: US-EPA, 2009. 100 IR-only Percent of cotton acres HR-only 80 St ac k ed traits 60 40 20 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Year FIGURE 1-6 Genetically engineered cotton acreage trends nationwide.
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From page 43... ...
Comparing the farmers' actions on fields planted to Bt and non-Bt cotton on the same farm controlled for variation in management, land quality, and machinery complement. The study found that one measure of human capital that was associated with a higher likelihood of adopting Bt cotton was experience (number of years of growing cotton)
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bIncludes all other states in upland cotton estimating program.
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. Those findings on human capital, yields, and the influence of pest problems are in accord with the explanations for adoption put forth by the diffusion and threshold theories.
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. The responses revealed that farmers growing corn on farms of less than 160 acres planted a greater percentage to GE corn for European corn borer control (54.5 percent)
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From page 47... ...
. DETERRENTS TO GENETICALLY ENGINEERED TRAIT DEVELOPMENT IN OTHER CROPS Soybean, corn, and cotton represent a substantial number of acres planted in the United States, but they do not reflect the diversity of American agriculture.
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From page 48... ...
That generally means that farmers growing such crops have access to genetic-engineering technology, whereas the option is not available to farmers growing specialty crops or crops that are not widely grown in the United States. The cost of regulatory compliance to ensure that GE crops do not pose unacceptable food safety and environmental risks has become an important component of the overall cost of new biotechnologies (Kalaitzandonakes et al., 2007)
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. Resistance to Genetic-Engineering Technology in Organic Agriculture As outlined above, genetic-engineering technology is not available to farmers of most crops.
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They also argued that organic agriculture is based on a set of values that places a high priority on "naturalness" (Verhoog et al., 2003) , a criterion that in their view genetic engineering did not meet.
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Social Effects The social effects of the adoption or nonadoption of geneticengineering technology have not been studied as extensively as those attributed to previous waves of technological development in agriculture, even though earlier studies demonstrated that revolutionary agricultural technologies generally have substantial impacts at the farm or community level (Berardi, 1981; DuPuis and Geisler, 1988; Buttel et al., 1990) and that there was a high expectation that genetic-engineering technology would also have substantive and varied social impacts (Pimentel et al., 1989)
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From page 52... ...
In the following three chapters, we examine how their adoption has changed or reinforced farming practices and what implications the changes have for environmental, economic, and social sustainability at the farm level. At the close, we identify remaining challenges and opportunities for GE crops in the United States and draw conclusions and recommendations for increasing their contributions to farm sustainability.
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From page 53... ...
2002. Use of transgenic Bacillus thuringiensis Berliner corn hybrids to determine the direct economic impact of the European corn borer (Lepidoptera: Crambidae)
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American Journal of Agricultural Economics 89(5)
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2003. Effect of postemergence glyphosate application timing on weed control and grain yield in glyphosate-resistant corn: Results of a 2-yr multistate study.
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1999. Evaluation of transgenic sweet corn hybrids expressing Cry1A(b)
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2002. Biotechnology and the European corn borer: Measuring historical farmer perceptions and adoption of transgenic Bt corn as a pest management strategy.
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From page 58... ...
2005. Transgenic corn for control of the European corn borer and corn rootworms: A survey of midwestern farmers' prac tices and perceptions.
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