North Dakota State
University Extension Service recommendations for canola are
to swath at the optimum stage to reduce green seed and seed
shatter losses. The canola swath should be allowed to cure and
ripen for a minimum of 10 to 14 days before combining.
"From 2004 through 2006, there have been
a number of small-scale and field-scale studies comparing
straight combining canola with traditional methods of swathing
and combining," says Kent McKay, NDSU North Central Research
Extension Center area agronomy specialist in Minot. "The results
of this research indicate that canola can be successfully
straight combined."
Combine headers, such as rigid, flex and
draper, all performed well with straight combining canola and
did not cause any harvest loss, compared with the pickup head.
When harvested at the optimum time,
straight combining canola can be successful with equal to or
higher yield than traditional harvest methods of swathing and
combining. There also is less green seed and generally higher
oil content and test weight with straight combining, compared
with swathing and combining.
"An important consideration with
straight combining is that it is more vulnerable to seed and
shatter loss when the harvest is delayed past the optimum,"
McKay says. "It is very important when straight combining canola
to harvest at the optimum time."
The optimum harvest time is identified
as the first time the canola moisture content falls below 10
percent. Research trials indicate that seed loss due to shatter
increases significantly approximately 10 days after the optimum
harvest time was reached with straight combining.
Spodnam and Biovital are polymers that
have been developed to reduce the seed shatter loss in
pod-bearing crops.
"Spodnam and Biovital were evaluated at
many trial locations," says McKay.
"There was no difference in yield with
the straight combining treatments with and without Spodnam or
Biovital when canola was harvested at the optimum time or when
harvest was delayed past the optimum."