11 March 2025. Paul McIntosh, Pulse Australia and WeedSmart.
Last week was the annual GRDC update at Goondiwindi with around 300 agronomists or advisors in the turnout.
Lots of issues and research presented with plenty of discussions, plus of course weeds and weed solutions were very prominent in various sessions.
The photo shows three of my Weedy peers from NSW, to the left of me in an early risers panel session.
Now weed issues at Quirindi and Dubbo in central part of NSW, where Pete McKenzie and Maurie Street respectively hail from, are very different to what we experience in Queensland. However, we all agree about the huge cost of weed control and what impacts weeds can have in our farming systems.
Control measures do vary for weed species and I really wanted to take away from this panel session, extra knowledge for our weed scene north of the border.
Now take a deep breath here , whilst I admit that somehow we are going to have to adopt, engage, use, apply some of these specific winter crop herbicides with an IBS tag on them. What is an IBS tag and that is for specific residual herbicides that need to be incorporated by sowing.
The general plan is apply these herbicides at the pre plant stage, then use a Tyne opener for the seeding operation with soil in-flow around the tyne and point system into the seed trench with usually with a press wheel behind that. All pretty standard for our deep seeding of chickpeas some year.
However, many of us in the Northern Australian region have preference for a single or double disc opener and press wheel set up in our heavier soil. By heavier I mean we have much less sand and more clay. Disc soil openers hardly leave a groove or soil trench rills, much better for upright stubble retention systems, can go in sooner into our wettish heavier soil types and gives us good seed to soil contact and eventual plant population establishment.
The issue is here within this IBS or Incorporated By Sowing technique along with the Critical Comments on several labels with these newer generation herbicides, is crop safety.
When they use a tyne or even a possibly a double disc opener in their loamier soils, they move the top soil area previously sprayed with residual herbicides, away from the plant line or seeding trench. This soil movement to the nearly next seeding trench is a key aspect of these herbicides crop safety.
So completely unlike our post plant pre emergent herbicides like Atrazine, Metolachlor, or even to some extent good old Chlorsulfuron, these group 15 and 13 mode of action herbicides , used mostly for Annual Ryegrass in Southern areas, certainly need good IBS methods to protect crop safety.
Can we do it physically with some modified planting systems and maintain our summer and winter cropping sequencing?
Not too sure am I at this stage, however with the increasing presence of Annual Ryegrass and even some of our more difficult weeds like Phalaris and Wild Oats, the search and development is on to handle this IBS requirement in our planting systems.
That's all folks.
Image caption: GRDC Goondiwindi Update Weeds Panel in March 2025.
L to R. Peter McKenzie, Maurie Street, Mitch Cuell, Paul McIntosh.
