Engineered Bt Corn
don't just plant a crop and then wait for the profits to roll in
at harvest time. They must manage the crops in order to get a good
yield. They invest in herbicides (glossary id 82) to keep weeds
from choking out crops, and insecticides (glossary id 83) to protect
their crops from pests like the European cornborer. The cornborer
attacks corn plants, reducing the yield. Chemical insecticides are
one effective way to combat this pest, but scientists have hit upon
know that a soil bacterium Bacillus thuringiensis (Bt) is a natural
· Scientists isolated the blueprint for a protein within
the bacteria's DNA. This protein kills insects.
· This Bt gene was combined with the recombinant DNA (glossary
id 27) of corn. By inserting the Bt DNA into the corn gene, the
makeup and heredity of the corn was changed. The Bt protein that
kills insects is now made by the corn plant. It is a hereditary
trait that can be passed on to its offspring, which will be resistant
to the European corn borer.
· Genetic engineering created a new type of corn.
and the proteins made by Bt have been combined and used effectively
against potato beetles and cotton boll worms to protect against
pests and help increase potato and cotton yields.
It is important
to understand that pests can become reistant to pesticides like
Bt. In the future, cornborers could become resistant to Bt corn.
Source: U.S. Department of Agriculture. "Adoption of
Bioengineered Crops." (Online.) September 2002. http://www.ers.usda.gov/publications/aer810/
y-axis: percent of genetically engineered Bt crops.
Bt Corn -first available in 1995, 8% in '97, 26% in '99, 19% in