DEALING WITH A GROWING ISSUE
NOT my favourite subject is our burgeoning problem of herbicide resistance; however it has me very concerned.
My experiences from the past few years make me cringe somewhat, since attending my first information day on herbicide resistance back the early 1990s, down in New South Wales.
Travelling down to Moree from my Darling Downs and Western Downs precincts, my purpose was to find out what those southerners were talking about with plants not dying with certain chemical applications.
One plant like ryegrass getting resistance status to a certain herbicide, I could maybe understand, however three or four different species with widespread potential of multi group chemistry resistance? I wondered how that could be allowed to occur.
Step up to Queensland in 2014 and now I certainly have a better understanding of this fast-developing issue.
We know we have some hard plants to control like fleabane, feather top rhodes, the easily stressed barnyard or urachloa grass patches and finally sweet summer grass, particularly in Central Queensland.
Of course this partial list is only our painful summer weeds and let’s not consider wild oats into our calculations at this stage.
Anyone just using a similar mode of action herbicide at every opportunity is riding for a big fall one day. We have done it with glyphosate for over 20 years as the price decrease of this valuable chemical fell down to $4 per litre for the 450 gram strength product.
I can still revisit some of my 1990s recommendations and am just staggered by the amount of straight glyphosate applications performed.
The comments column in my recco books was like an excuse list to only use gly. Cotton too close, Sprayseed too nasty on operators and downwind crops, other mixing partners too expensive, plant back concerns from companion products, glyphosate is a safe product, immediate moisture conservation and the list goes on.
So now we have all this herbicide resistance issue growing in Queensland, which is much different to my 1990 beliefs, what can we do? The answer to this is to have a plan.
You should always have a plan I believe.
In Queensland we have distinct summer and winter cropping rotation options that makes it easier for us to have a wide ranging plan.
The whole secret of beating your herbicide resistance level is to stop seed set by any means.
For more on working out you plan see part two of my herbicide resistance column in the next edition of the Rural Weekly.