Tuti yang baik,
Informasi Anda sangat berharga. Mestinya info semacam itu juga diperdalam dan
disampaikan ke para pihak. Sebetulnya memang ada beberapa penelitian yang
berkaitan dengan dampak negatif Bt ini. Tapi para pembela tetap saja
menegasikan temuan-temuan tersebut.
Di bawah ini berita salah satu penelitian lain di Iowa.
Salam
Rahmad
==========
> Biotech corn toxic to butterflies,
> study finds
>
>
>
> WASHINGTON (AP) -- A study of genetically engineered corn
>stirred
> new concerns about the crop after finding that it spreads
>enough pollen to
> nearby weeds to kill the monarch butterfly caterpillars
>that are feeding on
> them.
>
> Iowa State University scientists found that one in five
>monarch larvae died
> after being exposed to the toxic corn pollen for two
>days. Three days after
> the initial two-day exposure more than half the larvae
died.
>
> The biotech corn, known as Bt corn for a
> bacterium gene that makes it toxic to the
> European corn borer, became controversial
> last year after a laboratory study at Cornell
> University showed it was toxic to monarch
> butterflies. The Iowa State study was geared to
> approximate how the pollen would affect
> butterflies who encountered it in the field.
>
> "In the field you may have higher mortality rates
> because of the cumulative effect of being
> exposed to the toxin throughout the larval
> stage," said researcher John Obrycki, whose
> study appears in the Internet edition of the
> journal Oecologia. "Coming up with a good ecological
>assessment of this
> technology probably needed to be done before planting it
>across the
> Midwest."
>
> The Cornell finding produced a public outcry in Europe
>and calls from
> environmental groups to curb the spread of gene-altered
>crops, but biotech
> supporters have criticized that study and the one from
>Iowa State for being
> unrealistic.
>
> "Much of what (the Iowa State study) reports is based on
>analyses taking
> place in laboratory manipulations rather than field
>conditions," said Val
> Giddings, vice president of food and agriculture for the
>Biotechnology
> Industry Organization.
>
> But Jane Rissler, a biotech expert with the Union of
>Concerned Scientists,
> said more research needs to be done.
>
> "This is a study that confirms another study but this
>isn't the end of the story.
> It still hasn't resolved the issue," she said. "All of
>this should have been done
> five years ago instead of having this research come out
>in dribs and drabs."
>
> The Iowa State researchers planted breeds of biotech corn
>that produced
> different levels of the insecticide pollen along with
>some corn that hadn't
> been engineered. They then placed potted milkweed plants
>at varying
> distances from the fields. After two or three days they
>took the milkweed
> plants into the lab and exposed the butterfly larvae to
>the plant leaves.
>
> Significant numbers of the larvae died after exposure to
>leaves coated with
> pollen, while those placed with leaves that were washed
>or unexposed to the
> Bt pollen died at a normal rate.
>
> Giddings said butterfly caterpillars are unlikely to
>encounter the pollen in
> nature in any great numbers and that the monarch
>butterfly population
> increased almost as much as the plantings of Bt corn last
>year.
>
> An estimated 19 percent of the 80 million acres of corn
>growing this year
> was Bt.
>
> Environmental groups have petitioned the Environmental
>Protection Agency
> to have farmers surround fields of Bt corn with buffer
>zones of conventional
> corn to prevent the pollen from spreading to milkweed.
>
> The EPA has been reviewing its standard for biotech crops
>and plans to
> release recommendations in September, said Steve Johnson,
>deputy
> assistant administrator of the office of prevention,
>pesticides and toxic
> substances.
>
> Early this year the EPA put new planting restrictions on
>Bt corn to prevent
> insects from developing resistance to the toxin. The
>restrictions require
> farmers to plant at least 20 percent conventional corn in
>most regions, and
> 50 percent in areas where cotton is grown.
>
> In June, University of Illinois scientists placed black
>swallowtail butterflies
> near a farmer's field and found no evidence that they
>were harmed by the
> biotech corn. The swallowtail is considered less
>sensitive to the corn toxin
> than the monarch, but is more likely to be exposed to the
>pollen.
>
> Copyright 2000 The Associated Press. All rights
>reserved. This material
> may not be published, broadcast, rewritten, or
>redistributed.
>
>Jill Goetz
>Senior Public Information Representative
>College of Natural Resources and
>Division of Agriculture and Natural Resources
>University of California, Berkeley
>Phone: (510) 643-1042
>Fax: (510) 642-4612
>
***************************************
Miguel A. Altieri, Ph.D.
University of California, Berkeley
ESPM-Division of Insect Biology
201 Wellman-3112
Berkeley, CA 94720-3112
Phone: 510-642-9802 FAX: 510-642-7428
Location: 215 Mulford, Berkeley campus
http://nature.berkeley.edu/~agroeco3***************************************
