16 April 2024. Last updated 16 April 2024.
Macca’s Musings – by Paul McIntosh (Pulse Australia/WeedSmart)
We have come a long way since I took this photo in the 1980s and by that I mean we have adopted this farming practice called Zero Till or Conservation Farming methods. This practice has very much reduced our soil losses down the creeks and gullies into the Murray Darling river system and given us many soil structure and moisture accumulation benefits in our grain and fibre producing activities for the Aussie landscape.
We loved our herbicide revolution so much, we even looked and implemented extra agronomic practices at using herbicides to spray out our uneven maturing crops like grain sorghum, our pulse crops and even oilseed crops like soybeans with great success.
That is a key subject in our current slowly drying out paddocks around much of Queensland at the moment. When you experience mostly continuous rain events over a week or two as we have in April, some species of cropping plants react by regrowing very vigorously. Not exactly a desirable aspect in this usual harvest period of summer. With this excessive growth and more green leaves and pods appearing, the obvious solution is to spray it out, with our number one herbicide in Glyphosate.
Glyphosate controls green plants does it not? Well, as we have found again this season with the registered application rates we use, many are not able to get control over these suddenly very actively growing, supposedly annual plants of Grain Sorghum and Mungbeans.
So options are to use heavier rates of Glyphosate or mix and rotate other hopefully registered modes of action herbicides.
The heavier rates plan is a very bad option as that could well exceed any Maximum Residue Levels or MRLs in place for our very important export customers. At the worst if you go down the trail of using heavier rates than the labels say and then grain testing labs pick up this herbicide residue on your grain or pulse crop seed, it could well come back at you on the farm. And cost you a lot of money. This did occur many years ago, so is not just fairytale story.
Many countries adopt various MRLs for incoming grains. These Maximum Residue Levels can differ from country to country, depending if they follow the international system of Codex or they make their own levels up and surprise surprise, sometimes use it as a artificial trade barrier to Aussie goods.
I believe we have been okay without being superb in these very few MRL exceedencies over the last decade , however this season is going to test us out with our current greening crops.
I cannot state hard enough, how important it is to use the label rates, at correct timing and obeying any withholding periods, whilst also completing a signed grower declaration form on pesticides applied to your particular crop at delivery time.
I know how hard it is from my decades of agronomic advising, to fall into line with the export requirements of our various grains with pesticide use and still maintain grain quality and yields, however it must be done. The extreme sensitivities that grain testing labs around the world (including Australia) are achieving, is testament to the consumers desire to have food safety and cleanliness standards improving this century.
A badly eroded paddock after heavy rain.