SPECIAL REPORT: Bt crops: Arguments for and against (2)

2nd of three parts
DAVAO CITY (MindaNews/20 Dec) – Bacillus thuringiensis (Bt) is a soil bacterium embedded in the genomes of plants such as eggplant to make them immune to fruit and shoot borer worms. Bt was first isolated in 1901 in Japan from diseased silk-worm larvae and later isolated from Mediterranean flour moths and named Bacillus thuringiensis in 1911, according to Carie Swadener in an article published in the Journal of Pesticide Reform (Vol. 14, No. 3, Fall 1994) and posted in www.mindfully.org. Its commercialization in the United States started in 1958, and by 1989, it had captured 90-95 percent of the biopesticide market, Swadener added. Aside from eggplant, the microorganism has been injected into the genomes of cotton, papaya and corn.

Advocates of genetically engineered (GE) crops say that using Bt crops means reduced costs on the part of farmers since they will no longer buy pesticides. They have also assured the bacterium poses no threat to human health and that cultivating crops injected with it will have no adverse impacts on biodiversity contrary to warnings issued by local and international environment groups.

Dr. Eufemio Rasco, a scientist at the University of the Philippines Mindanao called Bt “a friendly bacteria [sic], certainly not pathogenic, and inhabiting the soil.” (MindaNews, December 9, 2010) “Humans and plants have been cohabiting with it for a long time, probably we’ve been eating Bt even before Bt eggplant,” he said in a forum in UP Mindanao on December 9.

Rasco flaunted the long span of time that Bt has been used as proof that it is safe for human consumption. “The bacterium has been with us for over a hundred years,” adding he was more afraid of the Bt spray than the Bt eggplant. Some organic farmers are using Bt spray derived from the same microorganism.

UP Mindanao recently conducted a field trial for Bt eggplant. But Davao City Mayor Sara Duterte ordered it stopped and the plants uprooted for reportedly failing to meet some requirements for the field tests of genetically modified crops. Groups opposed to GE foods likewise criticized the test for allegedly omitting risk assessment tests. After failing to get a reprieve and apparently feeling the combined pressure from City Hall and anti-Bt eggplant advocates, the university uprooted the plants, on December 17. The roughly 1000-sq. meter test site was enclosed with a cyclone wire about 6 feet high.

Field tests for the same crop were also done in Sta. Maria in Pangasinan; UP Los Banos, Bay, Laguna; CSSAC in Pili, Camarines Sur; Sta. Barbara in Iloilo; VSU in Baybay, Leyte; and University of Southern Mindanao in Kabacan, North Cotabato. Research professor Desiree Hautea of UPLB, is the project leader of the Fruit and Shoot Borer Resistant (FSBR) eggplant project, which is funded by the US Agency for International Development and receiving “technical support” from seed giant Monsanto, the same company that promoted and commercialized the other Bt crops.
Rasco allayed fears that enclosing the field test site with cyclone wire may not be enough to prevent the contamination of homegrown eggplant varieties through pollinators like bees. He said that in addition to the physical trap they have put up a biological trap (five rows of non-Bt eggplants) to confine the seeds and pollen within the wire enclosure.

UPLB entomologist Mario Navasero likewise said the possibility of Bt eggplants cross-pollinating with regular varieties is farfetched. He said “cross-pollination occurs only within a forty-meter radius and therefore the 200-meter buffer zone between the testing site [in UP] and the indigenous eggplant is more than enough.” He added the distance traveled by bees, the common insect pollinators, should not be an issue in that “it is the behavior of bees to identify specific sites for collecting pollen and nectars.
Once they have identified the site they only forage there and do not visit flowers along their way going to the site and back to their hive/nest.”

Navasero was reacting to a study made by scientist Remy S. Pasquet and cited by anti-Bt eggplant groups that bees can travel as far as six kilometers, contrary to Hautea’s declaration that the 200-meter radius was too far for the insects to fly.

“Bees can visit flowers as far as six kilometres away from their nest. From complete flight records in which bees visited wild and domesticated plant populations, we concluded that bees can mediate gene flow, and potentially allow transgenes to escape over several kilometres,” Pasquet, who made the study for the International Research Center and the Institut de Recherche pour le Développement, said. (www.biobees.com, Sept. 22, 2008) The research was funded by USAID and the Rockefeller Foundation.

Swadener added another unflattering observation that “large-scale applications of Bt can have far-reaching ecological impacts.” He said “Bt can reduce dramatically the number and variety of moth and butterfly species, which in turn impacts birds and mammals that feed on caterpillars. In addition, a number of beneficial insects are adversely impacted by Bt.”

“Insect resistance to Bt has been well documented. Genetic engineering may greatly expand use of Bt, speeding up the development of more resistance,” he warned.

Monsanto scientists themselves found that worms and other pests could develop resistance to Bt. In November 2009 they discovered that the pink bollworm had become resistant to Bt cotton in parts of Gujarat, Amreli, Bhavnagar, Junagarh and Rajkot regions in India, marking the first instance of Bt resistance that was confirmed by Monsanto anywhere in the world. (“Bt cotton ineffective against pest in parts of Gujarat, admits Monsanto,” The Hindu, March 6, 2010)

The Southeast Asia Regional Initiatives for Community Empowerment (Searice), in an open letter to Agriculture Secretary Proceso Alcala posted in its website, also expressed apprehensions over the possible impact of propagating Bt eggplant on biodiversity and on the livelihoods of local farmers.

“This is very alarming and it is a real threat and one only has to look back at what happened in Mexico where their local maize varieties got contaminated with Monsanto’s GE corn. It has seriously destroyed not only their local germplasm, but [also] the culture and traditions of the Mexican people that are so embedded with it. The same happened in Hawaii and Thailand with GM papaya, which seriously compromised the livelihoods of many Hawaiian and Thai farmers, and jeopardized the countries’ agricultural trade. To let this happen in the Philippines — and compromise our diversity and the livelihood of Filipino vegetable farmers — would be plainly careless and irresponsible,” Searice told Alcala.

For his part, Swadener acknowledged that Bt is an offshoot of researches made to look for pesticides that are toxic only to the target pest and pose fewer environmental hazards. “However, there is evidence suggesting that Bt is not as benign as the manufacturers would like us to believe, and that care is warranted in its use,” he warned.

And while Swadener admitted that Bt is less toxic to mammals and shows fewer environmental effects than many synthetic insecticides, he cautioned that “this is no reason to use it indiscriminately” and that “its environmental and health effects as well as those of all other alternatives must be thoroughly considered before use.”

He noted that “few studies have been conducted on the chronic health effects, carcinogenicity, or mutagenicity of Bt. People exposed to Bt have complained of respiratory, eye, and skin irritation, and one corneal ulcer has occurred after direct contact with a Bt formulation. People also suffer from allergies to the ‘inert’ (secret) ingredients. People with compromised immune systems may be particularly susceptible to Bt.”

He did not propose totally rejecting Bt but to use it “only when necessary, and in the smallest quantities possible” and as “part of a sustainable management program.” (Tomorrow: The economics of Bt crops)