GENETICALLY modified (GM) Bacillus thuringiensis (Bt) talong (eggplant) has no negative impacts on the biological diversity of nontarget organisms, the first-ever field-level study of the effects of insect-resistant Bt eggplants on nontarget arthropod species showed.
The study was carried out in the Philippines by researchers from the University of the Philippines Los Baños (UPLB) working with Cornell University. It has been published in the prestigious open-access scientific journal PLOS One.
The data, collected over three growing seasons in the Philippines’s main eggplant-growing region of Pangasinan, shows no significant differences between the number of insects and other arthropods and species between the GM Bt and non-Bt control eggplants. Anthropods include insects and spiders.
This finding is consistent with previous studies on insect-resistant Bt crops, such as cotton and corn, the study authors pointed out. The study came after the Supreme Court unanimous decision reversing its earlier ruling that temporarily stopped the field testing of the GM eggplant.
The paper is entitled “Assessing Potential Impact of Bt Eggplants on Non-Target Arthropods in the Philippines” and was published on October 31. The author of the study, which was subjected to PLOS One’s rigorous scientific peer review, is Dr. Desiree Hautea, professor of crop biotechnology of UPLB’s Institute of Plant Breeding, College of Agriculture.
“This first published report from extensive field studies of Bt eggplants affirms that the technology is ecologically benign,” Hautea asserted. Study coauthor Dr. Anthony Shelton, international professor of entomology at Cornell University, welcomed the publication of the results.
He commented: “This study confirms the environmental safety of Bt eggplant to non-target organisms under field conditions in the Philippines. Our previous study, published earlier in the same journal, documented the effectiveness of Bt eggplant against the destructive eggplant fruit and shoot borer. Combined, these studies clearly document the benefits of Bt eggplant to growers, farm workers, consumers and the environment.”
The study was funded by United States Agency for International Development, with match funding provided by the University of the Philippines Los Baños and the Philippine government’s Department of Agriculture Biotechnology Program Office (the funders had no direct role in the study, however).
The eggplants used were varieties (purple, long fruits) preferred by Filipino farmers and consumers, with the Bt gene crossbred into them from an original transformation event carried out in India by the seed company Mahyco, which donated its genetic technology to the project. The field trials were carried out between March 2010 and October 2012.
Bt eggplant could be of significant benefit to Filipino farmers and consumers, the study authors suggest, because conventional eggplant is typically sprayed with insecticide up to 72 times during the 180-day cropping season to control infestation by the eggplant fruit and shoot borer (EFSB) pest. Bt eggplant, as a previous study by the same authors has demonstrated, is fully resistant to the fruit and shoot borer pest, so it does not require pesticide sprays to prevent damage by this insect.
Filipino farmers use broad-spectrum insecticides for the conventional control of EFSB, including profenofos, triazophos, chlorpyrifos, cypermethrin and malathion.
In contrast, EFSB-resistant Bt eggplant varieties can be grown by farmers as part of a more ecologically friendly integrated pest management agricultural system.