New Zealand
April 17, 2007
Keeping brassicas free from
caterpillar damage – without the use of synthetic pesticides –
is the goal of research being undertaken at
Crop & Food Research near
Lincoln, Canterbury.
Research leader Dr Mary Christey has produced plants of these
species using molecular techniques – genetic modification – so
that the natural pesticide produced by the Bacillus
thuringiensis bacteria (known as Bt) is produced by the
plant.
She is now applying to the Environmental Risk Management
Authority for approval to undertake garden scale field tests in
Canterbury of the pest resistant forage kale, cabbages,
cauliflower and broccoli. A public hearing on this application
begins in Christchurch next week.
Contained tests like this one have been possible under existing
regulations for many years, and Crop & Food Research has
conducted 34 similar field tests on a range of crops since 1988.
Crop & Food Research’s General Manager Research Prue Williams
says it is important that New Zealand scientists continue to
explore the benefits of GM technology. “This application for
brassica research falls within the Government’s recommendation
to ‘proceed with caution’. What we learn from this study will be
essential to robust assessment of GM technology.
“New Zealand must be involved with GM research in order to
preserve options for the future. By staying on the leading edge
of this research we can continue to explore science which should
have outcomes of benefit to New Zealand.”
Dr Christey has been working on the problem of brassica pests
for more than five years and says there is great potential for
Bt-producing plants to kill caterpillar pests.
“As anyone who grows cabbages knows, caterpillar pests can wreak
havoc in a short space of time if they are not controlled.
“Under laboratory conditions, caterpillars feeding on cabbage
which has been genetically modified so it produces Bt all die
within 48 hours, and the plant is virtually undamaged.”
The natural pesticide only kills the caterpillars that are
feeding on these brassica plants, being mainly cabbage white
butterfly, diamondback moth and soybean looper. These are
serious pests of brassicas – the plant family which includes
cabbage, broccoli, cauliflower and forage kale – in New Zealand.
So far the work has been carried out in the laboratory and
controlled glasshouses. It has proved so successful that Dr
Christey now needs to test whether this success can be
replicated under field conditions.
Bt has been used as a biological control for insects for more
than 30 years. It is used by organic farmers worldwide as a
spray. In addition more than 30 million hectares of genetically
modified Bt crops were grown globally in 2006.
“The good thing about using Bt is that it has many different
strains, and each strain is specific to particular pests. In
addition, consumers of organically grown cauliflower and
broccoli have been eating the bacterium for decades and It has
not been shown to have any effect on the health of humans or
animals.”
Dr Christey says pest resistant brassicas could be grown with
far fewer applications of pesticides. “In the US the average
number of insecticide applications for cotton has decreased
fivefold largely because of the introduction of Bt cotton. We
expect that this pattern will hold true for pest resistant
brassicas as well.
“This is a great trend in terms of the environmental
sustainability of our food production and if pesticide use could
be reduced even further that would be great for the
environment.”
More information:
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Application summary
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ERMA have released their
Evaluation and Review Report on the Bt Brassica field trial
application.
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View the full
ERMA Evaluation Report. |
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