Title:
With Resistant Crops, Progress Can Raise New
Problems
Description: This is
a VOA Special English Agriculture Report.
See text below
Text:
Plant breeders and genetic engineers keep working to
give crops the strength to resist threats like
insects, diseases, droughts or floods. But before
you can resist a threat, you need to understand it.
We told you last week about a newly completed
genetic map of the organism that causes late blight.
That disease led to starvation in Ireland from
potato shortages in the middle of the eighteen
hundreds.
The new genome could lead to better ways to protect
potatoes, tomatoes and other crops. Science may
supply a stronger crop. Yet that does not always
guarantee demand.
Nik Grunwald from the United States Agriculture
Department worked on the international team that
completed the genome. He says it is possible to grow
potatoes that resist late blight. But these may not
look like Russet potatoes. And most American farmers
grow Russets because, as Nik Grunwald puts it, "that
is where the demand is."
Another example of scientific progress involves a
natural bacterium known as Bt. Bt is used as a
pesticide to fight cotton bollworms, corn borers and
other pests. Scientists have found a way to grow
cotton plants that contain a Bt gene, reducing the
need for pesticides.
But sometimes, when one problem gets solved, another
one appears.
In China, some farmers and researchers blame a
decrease in pesticide use for an increase in pests
unaffected by Bt. Also, there are concerns that some
organisms could begin to resist the plants designed
to resist them.
And in October, scientists reported on what they
call the "indirect costs" of a virus-resistance gene
in Cucurbita. This is the species of squash that
includes pumpkins and gourds.
The scientists say virus-resistant transgenic squash
are grown throughout the United States and much of
Mexico. The genetically engineered squash are
usually larger and healthier than wild squash.
But a three-year study showed that beetles like to
feed more on the transgenic plants, increasing cases
of wilt disease. The report by a team from the
United States and China appeared in the Proceedings
of the National Academy of Sciences.
The researchers point out that gene flow between
crops and their wild relatives is common and
difficult to contain. They note concerns that wild
plants could, as a result, gain genetically
engineered resistances. And these could affect the
natural balance in their environment.
And that's the VOA Special English Agriculture
Report.
Hi. I
personally reviewed this video and found it appropriate for
the news section of English Global Group. This
is a Voice of America video which covers an interesting
topic in Special English. I would appreciate some feedback from both
students and teachers about this video. You can comment in
the window below using any of a number of different services
including Facebook, Yahoo, AOL, and Hotmail.
To post a comment:
• Click "Comment using..." in
the window below
• Click your favorite service: Facebook, Yahoo, AOL, Hotmail
• Login to the service
• Click "Add a comment..."
• Post your comment in the window
Students: Please post a
comment stating what you found interesting about this video. You are
welcome to include links to your English study blogs and any
other materials you think might be useful for learning
English.
Teachers: Please post your
thoughts about this video. You are welcome to include links to
your sites, blogs, and any other materials you think might
be useful for learning English.
Hi. I
personally reviewed this video and found it appropriate for
the news section of English Global Group. This
is a Voice of America video which covers an interesting
topic in Special English. I would appreciate some feedback from both
students and teachers about this video. You can comment in
the window below using any of a number of different services
including Facebook, Yahoo, AOL, and Hotmail.
