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Discontinued Transgenic Products

FlavrSavr tomatoes
These tomatoes, introduced in 1994 by Calgene, contained a genetic sequence that made them soften more slowly than conventional tomatoes. The FlavrSavr tomato often was marketed as a transgenic variety that cost more because of its improved flavor. Calgene has said that there were quality control problems with the FlavrSavr. The company did not have access to the best cultivars, so the genetic sequence was inserted into a cultivar that lacked consistent production qualities. The resulting tomatoes sometimes fell below the marketing standards set for the FlavrSavr label. FlavrSavr tomatoes were available sporadically for several years, but eventually production was discontinued. Two informative and highly readable web pages on the FlavrSavr tomato are available at http://www.usis.usemb.se/biotech/tomatoes.html and http://www.comm.cornell.edu/gmo/crops/tomato.html.


Zeneca tomato paste
Zeneca tomato paste was another product openly marketed as transgenic. Zeneca tomatoes were slower to soften, as were FlavrSavr tomatoes, but the method for achieving this was somewhat different. In both tomatoes the activity of polygalcturonase, the softening enzyme, was reduced. But FlavrSavr tomatoes were engineered with an anti-sense gene for this enzyme while Zeneca tomatoes were engineered with a non-functional, shortened version of the gene. Safeway and Sainsbury's supermarkets in Britain stocked Zeneca tomato paste for about three years, but it was withdrawn in 1999 because of negative public opinion about transgenics in general. More information on Zeneca tomato paste is available at http://www.ncbe.reading.ac.uk/NCBE/GMFOOD/tomato.html.


NewLeaf potatoes
Monsanto's NatureMark "NewLeaf" potato, genetically engineered with the Bt gene to provide resistance to insect pests, was first marketed in 1996. Two additonal products, NewLeaf Y, which had Bt and resistance to potato virus Y, and NewLeaf Plus, which had Bt and resistance to the potato leaf roll virus, were introduced later. NewLeaf potatoes never commanded a large share of the market, partly because several fast-food chains and chip makers declined to accept them. Monsanto announced in the spring of 2001 that NewLeaf potatoes would be discontinued so that the company could focus on more profitable products. More information about NewLeaf potatoes is available at http://www.comm.cornell.edu/gmo/crops/potato.html. A news story on Monsanto's announcement is available at http://cbc.ca/cgi-bin/templates/view.cgi?category=


Triffid flax
Triffid flax, developed by the University of Saskatchewan to be tolerant to the herbicide sulfonylurea, was discontinued in the spring of 2001. Canadian flax growers were concerned because their biggest customers, European buyers, declined to buy GM flax. Worries about possible contamination of conventional flax seed led to the withdrawal of Triffid flax. A story on the discontinuation is available at http://www.cp.org/english/online/full/agriculture/010621/a062152A.html.


StarLink corn
StarLink corn, like other kinds of Bt corn, was genetically engineered to be resistant to the European corn borer. In tests, the Bt Cry9C protein used in StarLink corn showed several similarities to allergens. Among other characteristics, it was slower to break down in simulated disgestion tests than the Cry1A protein used in other kinds of Bt corn. Concern about the possibility of allergic responses led U.S. regulators to approve StarLink corn for production with the restriction that it be used only for animal food or non-food purposes. Before regulators could determine whether the Cry9C protein was allergenic or not, it was reported that StarLink corn products were showing up on grocery store shelves. Aventis, the maker of StarLink corn, discontinued seed sales in the fall of 2000. More information on StarLink corn is available on our StarLink news page and on our Hot Topics page dealing with StarLink corn.


Bt 176 corn
The transgenic corn known as Event 176 was used to produce Bt seed corn sold under the labels KnockOut (Novartis) and NatureGard (Mycogen). In contrast to other types of Bt corn, sold as YieldGard by Novartis, Cargill, DeKalb, and Pioneer, the pollen from Bt 176 corn was toxic to Monarch caterpillars, which often live in corn fields but do not eat corn. Studies showed that even small amounts of this pollen caused Monarch caterpillars to eat less of the milkweed leaf tissue that is their exclusive diet, and amounts of pollen commonly encountered in corn fields killed many of the caterpillars. Bt 176 corn was not a commercial success, probably because it provided good protection against the European corn borer early in the summer but not later in the season. It was estimated that acreage planted to Bt 176 varieties constituted 2 percent of the total in 2000, declining to 1 percent in 2001. The registration was allowed to lapse in the fall of 2001 and no more of this kind of corn will be sold. More information is available on our Hot Topics page dealing with Bt and Monarch butterflies.


Page last updated : March 11, 2004

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