Correct crop desiccation
FOR many years now we have adopted farming practices of using herbicides to help in the dry down of our crops, after they have reached physiological maturity.
This herbicide desiccation operation in winter and summer crops really does allow us to get the headers into the paddock much sooner, rather than just allowing natural plant drydown.
Of course the challenge is always the judgement of assessing the over 90 per cent physiological maturity mark in our annual crops, which is the rough figure most agros use when scouting paddocks for desiccation timing. Physiological maturity has terms such as black point or black layer, which indicate in cereal grain, the seed has stopped filling and is separated from the mother plant. So logically, no external factors in that crop such as more irrigation/rain events or even environmental factors such as frost could affect the size or fill content of this grain. In legumes such as soybeans and mungbeans this physiological maturity timing is when the seeds in the pod have separated from the white membrane lining the plant pods.
So our best practice of crop desiccation is a necessary part of our farming system for drying down our crops to enable the harvest to occur, as soon as the header can operate and the grain sample is good.
The drier all the plants are, including the weeds in the paddock, the quicker and more effective is the harvest operation.
So having outlined the many of the benefits in desiccation that we have been using for over 30 years in some crops, what can go wrong in the future?
Some shock news last week was the intention of Europe to ban the active ingredient diquat (originally known as reglone) and all associated products in the EU. So unless negotiations by our grain export leaders in the European region are successful, by early 2020 this long-term desiccation product will no longer be able to be used in Australia for export pulse or oilseed crops to the EU.
Then a couple of weeks ago, there was major media exposure on our very useful farming product in glyphosate. The pressure is coming from everywhere, isn’t it, on our pesticide usage patterns?
What all this highlights in the year of 2018 is that our absolute critical herbicide weed control methods, which we have developed and used over many years, are getting strangled by forces outside our control.
These outside forces highlight a few things or warnings to me.
We all need to adhere strongly to the labels or the permitted use on all pesticide products.
We know from bleak experience the EU takes exception to having the grass killing active ingredient of haloxyfop MRLs exceeded in exported pulse crops to them. I believe some EU countries refuse to have our favourite fop herbicide at all on imported produce. This one example sure gives me the enthusiasm to explain at every field day I attend, to not apply this handy grass control agent of haloxyfop on to flowering pulse crops. Many labels are confusing on timing and some placement of wording is tricky to understand, when just glancing at the small print that labels often carry, so read carefully.
The second thing is our herbicide resistance levels are increasing and with large rainfall events being received by some of us , the amount of weed growth is enormous. So we have large numbers of weeds growing with herbicide resistance spreading rapidly. Many of us are going to be tempted to use larger rates of herbicide both in fallow and in-crop.
We are really pushing the boundaries and with so much sophisticated grain testing equipment these days, it could end in tears and be very costly for the grain producer.
So once again, I challenge us all to find and practise alternative cultural methods of weed control. It is a numbers game as usual with weed seeds, just like the heloithis resistance problems we had in the late ‘80s and ‘90s. Stop the weed seed set by other means, other than the herbicide bandwagon with a diversity of options.
We need our herbicides to last for many years yet, so antagonising our overseas markets and increasing the herbicide resistance levels on our own farms does not make sense to me.
My own lifetime of experience with pesticides use has been positive and I want that to continue along this pathway, however we need to be pragmatists and look at other options for pest control, especially our weeds.
PESKY WEEDS: Fencelines can become nurseries to weed seeds.