Canada
August 10, 2009
Straight cutting canola can
improve yield and seed quality and it can be economical, but the
right conditions must exist, says Tiffany Martinka, agronomy
specialist for the
Canola Council of Canada (CCC).
"Make the decision to straight cut over swathing after you have
assessed canola fields individually," says Martinka. "It’s all
about minimizing losses due to pod shatter and drop. Anything
that may have weakened the pods or petioles makes a canola crop
a less than ideal candidate for straight cutting."
The CCC advises growers to assess each canola crop carefully
before choosing straight cutting, based on four factors:
Crop canopy
The crop should be well knitted and slightly lodged to
reduce potential seed loss through pod shelling and drop. If
a large proportion of the plants appear to move
independently in the wind, they will be at high risk for
shattering loss as the plants senesce and dry down. The
plant stand should be thick (hard to walk through). Pod
integrity can be affected by frost, drought and insect
damage. A uniform crop with minimal green weed growth is
also a huge advantage when straight cutting.
Disease
The crop should be relatively free from blackleg, fusarium
wilt, sclerotinia and alternaria, as these diseases can
result in premature ripening, causing the crop to be prone
to pod shatter.
Hail
Crops affected by hail are poor candidates for straight
cutting because the physical damage reduces pod integrity
and they normally see greater disease infection. If late
season hail is common in a certain area, growers should keep
in mind that hail will typically cause more damage to a
standing crop than a swathed crop.
Frost risk
Canola seed is at significant risk for fall frost damage
until seed moisture drops below 20%. This moisture drop will
take much longer in a standing crop, and as such, late
maturing crops are poor candidates for straight cutting.
They will be much more vulnerable to yield loss, and to
downgrading from frost damage when standing.
Short, severely lodged, or
excessively branched canopies may be candidates as well, because
if swathed there would be minimal stubble left to anchor the
crop. In this situation growers should consider the potential
for wind damage to the swath relative to shattering risk if left
standing.
"Growers should also note that when trying pod sealants for the
first time with straight combining, it is important to leave a
check strip" says Martinka. "Conditions vary from region to
region and even field to field, so with check strips, producers
are able to see whether a product was useful for them on that
field, that year. Over time this information will help determine
what crop conditions are most likely to benefit from an
application."
Timing of straight cutting is also an important consideration,
says Martinka. "In order to get the proper seed moisture
content, straight cut harvest often requires a delay of two
weeks or so relative to a swathed and combined canola crop. The
crop should be harvested as soon as the seed moisture and
percentage green seed have dropped to acceptable levels, in
order to minimize the time the crop is susceptible to wind
damage. The main stems will often still be retaining some green
colour".
Keep in mind that the distinctly green % cut-offs for No. 1, 2,
and 3 Canada canola are 2, 6, and 20% respectively. More
information on canola grading can be found on the Canadian Grain
Commission website at
http://grainscanada.gc.ca/oggg-gocg/10/oggg-gocg-10e-eng.htm.
Martinka also advises that reel and ground speed should be kept
evenly matched when straight cutting. "Producers should consider
cutting at an angle to the direction of lodging to minimize
shelling losses that are caused by the header. Combining in this
direction also helps canola to feed into the combine more
smoothly, which helps reduce harvest losses".
If straight cutting canola at seed moisture above 10% as a
strategy to reduce losses out in the field, growers are advised
to have adequate bin space with aeration and/or drying capacity
since safe storage will be an issue at higher seed moisture
contents.
If considering straight cutting for the first time this year,
growers are advised to start with a relatively small number of
acres and build up from there in future years, says Martinka.
This way, growers have a chance to assess whether straight
cutting works for them and their own farm management.
To learn more about straight combining, go to the Canola Growers
Manual online:
http://www.canola-council.org/contents11.aspx.
And check out this fact sheet:
https://canola-council.merchantsecure.com/canola_resources/product35.aspx. |
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