Australia
May, 2007
Cotton Seed Distributors
article
A video version is available
at
http://www.csd.net.au/default.asp?file=/showwow.asp?wow=2394
Welcome to this weeks Web on
Wednesday. In August 2006, Federal Regulators approved Liberty
Link® cotton technology in Australia. Liberty Link® cotton is a
new technology to Australian farmers which allows them to use
Liberty herbicide for the over-the-top control of hard-to-kill
perennial and annual weeds in cotton systems.
This week we will be talking to Mick Brosnan from B & W Rural in
Mungindi and Sarah Wilson from Bayer CropScience in Goondiwindi
about their experiences with Liberty Link® cotton.
The values of Liberty Link® cotton
can be best summed up in four points:
- The enhanced control of
hard-to-kill weeds like peach vine,
- control options for
volunteer cotton including Roundup Ready® volunteers,
- providing growers with an
interesting option in terms of rotation choice in herbicide
and technology for their production systems,
- and importantly, this
technology will help the industry to maintain its current
weed resistant status.
Sarah
Wilson, Bayer CropScience
I’m talking with Sarah Wilson from Bayer CropScience. Sarah
has been involved in a lot of the research and development work
with Liberty Link® cotton. Sarah, can you just tell us about the
Liberty herbicide, how it works and what it looks like when it
is sprayed?
The Liberty herbicide itself has the active ingredient
glufosinate-ammonium. The way this herbicide works is that it
causes a breakdown in one of the essential plant metabolism
lines and it causes a build-up of ammonia within the plant which
essentially leads to plant death. What you generally see after
application is that within about five days you will start to see
yellowing-off on the weeds. Plant death is probably (depending
on climatic conditions) within anywhere from 15-20 days
afterwards.
You have assembled a substantial list of the weeds it does
control. Can you tell us what is going to be on that list?
Yes the weeds on the list at the moment are annual polymeria,
bell vine, bladder kepmia, caltrop, conventional cotton and
Roundup Ready® cotton (which obviously includes Bollgard®
varieties), dwarf amaranth, European bind weed, paddy melon,
peach vine, red pig weed, rhyncosia, sesbania, sow thistle,
yellow vine and at the moment we also have a suppression claim
for Chinese lantern, noogoora burr.
Over the next few years, we will continue to add weeds to the
label and continue work so those suppression claims will
probably be upgraded to control but it is just a matter of
getting the field trials done to make the claim on the label.
Just from your experience with your trial work so far, is
there any group of weeds that there may be a slight limitation
on?
This product is (I would have to say) stronger on broadleaf
weeds as opposed to grass weeds. So, while it does control some
grass weeds in some instances, we have got no label claims at
the moment and we are probably a lot more comfortable sitting
with broadleaf weed control.
What sort of stewardship program or training will be required
for growers that decide to use Liberty Link®?
There will be an accreditation program. We will be running those
over the next couple of months. Basically the growers will be
accredited on the use of the herbicide and the growth of the
crop and the Technology Service Providers (TSP’s) will also have
an accreditation process and then auditors will go through an
accreditation process as well. That will all be a one day
process where the growers will come in for a couple of hours and
then if they want to stay for the audit process then they can;
it will be another couple of hours on top of that.
Can you just give us a comment on the application windows for
this product in terms of crop stage or time of the season?
Basically with this product, the cotton is completely tolerant
to the herbicide so there is no limitation as far as the crop is
concerned. The problem is withholding periods, so the
application is up to 70 days before picking because of the
withholding period. The important thing is that the application
of the herbicide is based on weed size, not crop size, so we are
targeting weeds at 2 – 6 leaf stage as opposed to looking at
crop stage limitations.
If some growers next year wanted to try it this technology
out, could you give some suggestions. Would it be good to pick
out a bad field with vine for instance and try it out?
Yes definitely, fields where you have had traditionally had
broadleaf problems or where you are looking to just clean it up
after other cotton varieties (cotton volunteers). This year we
had a grower put it into a brand new field (so it’s the first
year in crop) just to tidy it up and get rid of some of the
vines and things so that’s where he saw a real fit for it on his
farm.
Michael Brosnan, B & W Rural, Mungindi
I am talking with Michael Brosnan from B & W Rural in
Mungindi. Michael has had a couple of years experience with some
of his clients using Liberty Link® technology. Michael can you
just give us a summary of how you found the technology?
I found the Liberty Link® technology very good. As you said we
have had two years now and we have basically found the product
to be very good on all the broadleaf weeds.
Last season particularly, it was out as “Cleveland” (Mungindi)
it was on some brand new country which we knew would be very
dirty including some bad take-all (polymeria longifolia – the
bad one) and we found it to be quite good on suppressing it,
which was enough to let the cotton out-compete the polymeria and
all the other broadleaf weeds. We had a pretty broad range of
weeds and we were very happy with the result.
We put Stomp® down pre-plant because we were concerned that it
isn’t a great product on grass but they did some trials where
they left the Stomp® out and actually found it to be quite good
on the grasses as well so in future years we might go back to a
band of Stomp® at a lower rate.
You said they did some trials with the planting herbicides;
they also did some trials with lay-by as well?
Yes they left some lay-by out and they were still very happy
with the Liberty Link®. It suppressed the weeds enough, but I
think you would have to assess it every year; season by season.
Some years I think you would still need to put a lay-by down;
other years (like last year) it looked like we probably would
have got away without a lay-by.
What comments could you make on some of the specifics in
terms of application of the Liberty product?
The main key (in which Bayer told us to do) is that coverage was
the king and actually they were recommending up to 200 litres of
water to the hectare and that’s what we did; we put 200 litres
of water to the hectare out to get really good coverage and I
think that is the key to the product. It is pretty hard to
swallow when growers are use to putting out 50 up to a maximum
of 100 litres of water to the hectare but I think that is the
key to this product; water volume.
In a system where there are a range of weed control
technologies available, how do you specifically see the Liberty
Link® fitting into a farming system?
I think that one of the real benefits of this product will be as
a rotation tool to combat the Roundup Ready® volunteers. The
Roundup Ready® volunteers are a real issue, especially for the
growers that water-up but also for the pre-waters it still
becomes a problem there as well. So that’s where I see this as a
really valuable tool, you have one season of Roundup Ready® and
then follow it with a season of Liberty Link®. Obviously the
technology is only in Sicot 80 conventional at the moment but we
need it into the Sicot 71 line both (Bollgard® and conventional)
eventually.
Just on the Sicot 80L; you have probably seen it as much as
anyone has. What are your comments on that variety in terms of
its management and performance?
Sicot 80 is a good variety, especially if water is a little bit
limited. For this area the Sicot 71 line is absolutely
exceptional if you have got full water and good soil (which most
of this country is), but Sicot 80 is a very good performer and I
think the Sicot 80L and Sicot 80 conventional are identical in
terms of management; you wouldn’t manage them any differently I
don’t believe.
Liberty Link® cotton is being developed in collaboration
between CSD, CSIRO and Bayer CropScience. In 2007 we will have
two Liberty cotton varieties available for growers to consider
using.
They will be;
• Sicot 80L which is a variety suited to the warmer Northern and
Western areas of the cotton belt
• Sicot 43L a variety which has got good opportunity in the
Eastern and cooler areas.
We do have in development stacks of Liberty Link® Bollgard II
and those varieties will be available to growers in subsequent
seasons. |
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