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Asgrow/Dekalb early orders going on now.
Soybean seed is extremely tight, so I suggest getting it bought wherever
you purchase your seed.
Here is a little info on soybean rust. As we go throughout the
year, I will try to keep this page updated with the latest and greatest
info we have on soybean rust. Like where it’s at in the country and when
or if it will get here.
What
is soybean rust?
Soybean
rust is caused by two fungal pathogens:
Phakopsora pachyrhizi,
or the Asian type of rust, is the most destructive pathogen of the two and
the one that poses the biggest threat to the North American soybean crop.
This has been found in
Australia
,
Africa
,
South America
,
Asia
, and most recently in the
United States
.
Phakopsora meibomiae,
by contrast, is less aggressive and is not known to cause severe yield
losses in soybeans.
Today, there are multiple races of soybean rust. More than 40 races
have been identified in
China
, 18 in
Japan
, and 2 in
Brazil
.
How
does soybean rust develop?
Once rust
spores land on a host(soybean), they must germinate and grow into tissue.
The disease infects the tissue and produces more spores for more possible
infection elsewhere. The presence of the soybean rust pathogen alone is
not sufficient to cause infection. To survive, it needs suitable living
host and environmental conditions conducive for disease development. Six
hours of free moisture (heavy dew or rain) with temperatures between 59-82
degrees are needed for optimum spore germination. Under these favorable
conditions the disease cycle is continuous and spreads rapidly. Soybean
defoliation has occurred as quickly as 7 days, if left uncontrolled.
Seed-borne transmission of soybean rust has not been documented.
Can
this pathogen over-winter in
North
America
?
For most
of the
United States
, soybean rust will not over-winter. The
pathogen must over-winter on host plants such as the kudzu in
South Texas
, southern
Florida
and other coastal states. Spores cannot
survive more than 5 days of temperatures below 39-41 degrees.
How
has soybean rust moved on a global basis?
Soybean
rust spores are windborne, thus it is highly mobile. Wind currents carried
spores from
Uganda
to
Zimbabwe
– approx, 1,200 miles – in 2001. From
2001 – 2003, it traveled more than 1,500 miles, from
Paraguay
to near the equator.
How
do we protect our soybean crop?
The
disease can be effectively controlled with the use of fungicides.
Experience in other countries suggests early detection and prompt action
are key to controlling the disease. These methods usually run around $13 -
$18 per acre.
There are several websites to get valuable info on this disease,
including these listed below:
www.stopsoybeanrust.com
http://www.soygrowers.com/rust/default.htm
, http://www.aphis.usda.gov/ppq/ep/soybean_rust/
www.unitedsoybean.org/soybeanrustguide.pdf
, http://www.apsnet.org/online/feature/rust/
http://deltafarmpress.com/news/050315-brazil-rust/
As bad as this disease sounds, don’t panic.
Northeast Kansas
is projected to have the spores travel to
our area about 30% of the time (3 of every 10 years). There are actions to
prevent it, but he most important is to keep an eye on what’s happening
south of us.
Texas
winters are vital to us getting the
spores. If
Oklahoma
gets them, then get out and spray your
soybeans.
We do have several advantages in
Northeast Kansas
.
1-
We don’t usually have the
dews like they do southeast of here.
2-
We are west of the
Mississippi
(anything east is more apt to get it)
3-
Winds generally blow from the
south. (if it doesn’t over-winter in
Texas
, we will probably be safe)
If
you have any questions, please call and I’ll be happy to help you. We
wish you a successful 2007 and thank you for your business.
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