Establishing canola into retained stubble - how to make it work!
The annual Streatham ute drive was held last Thursday and an excellent turnout of 50 growers,
advisors and industry reps was on hand. Paul Breust & Aaron Vague showed off the work being done
as part of the GRDC funded stubble project.
The first stop was on Scott Blurtons property where replicated plots were direct drilled into retained
stubble of different heights with his JD 1890 single disc opener. Stubble was harvested at 30cm tall,
spread and retained, 15cm, spread & retained and 30cm, windrowed and baled. The aim is to see if
higher stubble reduces establishment, early & late growth and final yields. No significant differences
were found for establishment between any of these treatments which is encouraging for growers
wishing to remove the need to burn paddocks prior to sowing.
Paul listed a range of benefits and potential problems when retaining stubble. He also outlined the
benefits that disc seeding equipment can bring to a stubble retained sowing system. Excellent trash
handling, lower horse power requirements, increased sowing speeds and therefore more hectares
sown per day. He warned growers that there can be some problems associated with using disc
seeding equipment. Disc’s generally cannot handle sowing conditions as wet as a tyne, there are no
registered pre-emergent herbicides for disc seeding systems, some conditions increase crop damage
from pre-emergent herbicides and some disc seeders require increased levels of maintenance in
comparison to tyned seeders. For all the data and info presented on the day visit the SFS web site
using the link below. (add link to web)
Each strip was 2 seeder widths wide and one seeder strip was rolled post sowing to determine if
there was a negative effect on slug numbers. Unfortunately, or fortunately, there were no slugs
found from sowing until now so no data was able to be collected for this purpose. Rolling did not
have a positive effect on establishment at this site.
Stop 2 was at a similar trial where we compared the establishment, seed placement and early
growth for a JD disc and Myles Reads Morris contour drill in replicated and randomised strips at
paddock scale. The disc sowed into 30cm high stubble and the tyne used the more traditional
method of 15cm high stubble with the trash spread. Again there were no significant differences
between establishments but there was a significant difference between early growth in some strips.
These were considered to be a results of variability in the paddock and not related to seeder
performance. ( add link DvT handout)
At stop 3 Annieka Paridaen discussed the practice of sowing long season winter habit varieties of
wheat & canola to take advantage of substantial summer rainfall. Annieka has been trialling this
practice for several years and detailed the pro’s & cons for farmers with livestock, soil benefits and
successful management techniques. The group were shown a crop of CL971 sown in January 2015
which had not been grazed and its was significantly in front of nearby Autumn sown canola. Annieka
expressed that not grazing can have detrimental impacts on crop performance as grazing has been
shown to minimise disease and insect damage. The biggest advantage of this system is the large
roots mass developed as a result of early sowing. This allows these crops to source additional
moisture and nutrient throughout the growing season.
The final stop on the drive was to a site where Aaron Vague outlined the trial work being conducted
on harvest weed seed capture techniques at Gary Meeks property. The treatments tested were
harvest high & burn all stubble, harvest at 15cm to collect weed seeds and windrow burn and
harvest low and treat the chaff with a weed seed mill integrated (PIM) into the header. The aim is to
determine how many weed seeds can be destroyed by each treatment as part of an integrated weed
management program.
The site had high numbers of annual rye grass, giant brome and wild oats at harvest last season.
Counts collected pre harvest showed that 36% of weed seeds were situated below 15cm high and
would not be collected by the low harvest height and thus treated by the windrow burning or the
weed seed mill. A similar site at Inverleigh late sown with Barley which was much shorter resulted in
95% of weed seeds being captured which is at the critical level required to reduce weed seed
numbers. The 65% weed seed capture had not reduced this year’s weed germination enough to have
a positive impact and Aaron was looking forward to seeing how a few years’ treatments would
impact over time. (add link HWS handout)
A small plot trial has been sown at Lake Bolac trials site to test how sowing date, variety and harvest
height impacts on the numbers of weed seeds collected at harvest. This is a replicated trial aiming to
find out how growers can manipulate their crops to get the best result from harvest weed seed
capture techniques.
Overall a very interesting afternoon was had with excellent discussion on the trials and the existing
outcomes. It finished with an informal gathering at the Lake Bolac pub where the discussion
continued. Some interesting points to note from the day were;
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At Scotts, a CT site, wheel tracks initiated higher emergence of ARG
Portuguese millipedes at numbers 50/m2 did not seem to damage seedlings
Harvesting 10cm lower is 10% slower
Sheep did not have a big detrimental effect on windrows and burn temperatures at this site
Burning windrows at Inverleigh escaped into surrounding stubble
Stubble incorporated late at site 2 seriously blocked the tyne seeder but the disc was fine
Coming up 
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Seeder demonstration site visit Inverleigh & Bradvale – 30/7/15 1pm
Boom spray demonstration and training day Mininera Footy oval – 11/9/15