Transgenic Rootworm Corn: Assessing Potential Agronomic, Economic, and Environmental Benefits

Abstract

The potential benefits of transgenic rootworm corn (Cry3Bb1 protein) are expected to include: increased root protection; increased intangible benefits to farmers (safety of not being exposed to insecticides, ease of use and handling, time and labor savings, better pest control); increased economic benefits to farmers ($231 million from yield gains [$25-$75/acre relative to no insecticide control, $4-$12/acre relative to control with a soil insecticide] and $58 million in reduced insecticide risks and time savings); reduced incidence of corn stalk rot; and increased yield protection (9 to 28% relative to no insecticide use, 1.5 to 4.5% relative to control with a soil insecticide). If transgenic rootworm corn is planted on 10 million acres, the annual impact will be a reduction of 5,344,462 lb a.i. (75.2%) of insecticide use; increased resource conservation (3.07 to 5.23 million gal of diesel fuel equivalents conserved that would have been consumed in the manufacture and delivery of insecticides); increased water conservation (5,657,734 gal of water not used in insecticide application); conservation of aviation fuel (68,845 gal of aviation fuel not used); reduced farm waste (1,187,035 fewer insecticide containers used); increased planting efficiency; and improved safety to wildlife and other nontarget organisms. Accepted for publication 1 February 2004. Published 1 March 2004.

Scientific Opinion on an application from Pioneer Hi‐Bred International and Dow AgroSciences LLC (EFSA‐GMO‐NL‐2005‐23) for placing on the market of genetically modified maize 59122 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003

“…Therefore, maize 59122 is expected to result in a reduced environmental load from chemical insecticides (Alston et al, 2002;Rice, 2004), and lead to fewer adverse side effects on non-target arthropods in the maize ecosystem, when it replaces chemical insecticides (Marvier et al, 2007;EFSA, 2008b;Wolfenbarger et al, 2008;Naranjo, 2009). As indicated in Section 6.2.3.1, the cultivation of maize 59122 could lead to the evolution of resistance in the target pest and so cultivation practices will need to be adapted accordingly.…”

Susceptibility of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) to the Entomopathogenic Fungus Metarhizium anisopliae when Feeding on Bacillus thuringiensis Cry3Bb1-Expressing Maize

“…Since 2003, Diabrotica-resistant transgenic maize expressing the cry3Bb1 gene from the bacterium Bacillus thuringiensis (Bt maize) has been grown commercially in the United States (12,15,49). The deployment of Bt maize has huge potential for reducing insecticide applications and yield losses (8,39). Continuous exposure to the B. thuringiensis protein, however, puts high selection pressure on the pest population and may lead to the development of resistance, as has frequently occurred with chemical insecticides (10,23,41,44).…”

The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM

“…In higher value crops, such as seed maize, popcorn and sweet corn (Shelton et al,chapter 9), management is more aggressive and in some cases may use biologically-based insecticides or biological control (e.g., Kuhar et al, 2003;Musser et al, 2006 In the USA estimates of insecticide a.i. applied annually to control this pest complex range from 2,400 to 3,500 MT (Gianessi et al, 2002;James, 2003;Rice, 2004). This represents approximately 60% of the total insecticides used on maize pests in the USA and, as mentioned previously, 25-30% of the insecticides used against maize pests worldwide.…”

“…However, coleopteran-active Bt maize shows a much greater potential benefit in the near future, as insecticides used against Diabrotica spp. comprise 25-30% of the global total in maize (James, 2003;Rice, 2004). Table 5.3 Important lepidopteran and coleopteran (Diabrotica spp.)…”