Not all crops enjoying cold
AS YOU travel around our mostly very dry region, you do observe some paddocks beginning to green up.
No, not only with weeds, there is some winter crop in there as well.
Like the photo (pictured) of some very early planted chickpeas. It’s clear they are not liking the very cold mornings at all.
Indeed, I have looked at in past years, chickpea crops actually killed by frosts.
In a very cold winter of the early 2000 years, I had call to inspect a barley crop on the banks of Westbrook Creek, just west of Toowoomba.
It was nearly white and very prostrate in an unsprayed section in the mid-tillering stage and where we had sprayed with 24-Damine a couple of days previously, the crop never did recover.
We all realise very much how frosts can impact on our cereal and legume crops in their reproductive stages, however what can you do to guard against frost damage in July when it really is expected to get cold?
The answer is not much and we used to speculate about the term “cold hardened” – this refers to our winter cereal crops gradually getting accustomed to days of cold conditions by a bio-physiological process.
In other words, cold hardened.
Our dry soil conditions also act as an insulator and are not warmed in the daytime by the sun, so colder night time temps are experienced over these paddocks.
Moist soil profiles however are heated during the day and this stored heat is re-radiated out in the night time close to the ground, to take the edge off those cold and still frosty nights.
Windy nights also have a lower frost expectation by many of us.
Unfortunately one of our best assets in dryland farming is maintaining stubble from previous crops, and this adds to our increased frost damage by lower canopy temperatures.
The other issue in cold conditions for some of our numbers is applying a herbicide for weed control.
I have seen some dreadful crop affects with many, if not all, our herbicide range after being applied to frost-affected crops.
Even that sudden transition from warm too cold in a few days can leave your plants’ metabolism very weakened and not able to metabolise (grow out) any recently applied herbicide out of its system.
One of the worst sights I have seen is Metsulfuron applied on a wheat crop a few days before some first of the season big frosting events.
These mid-tillering wheat plants copped a battering and were prostrate on the surface for many days.
Fortunately some rain did arrive and assisted in some recovery.
So with herbicide application timing, you really need no growth stopping events like a frost to be at least seven days either side of your planned application.
Even then, with my experiences in stating seven days, I would be assessing my crops’ recovery from these cold snaps before application of any herbicide product and it may turn out to be 14 days delay.
Note I said either side of your application timing, as spraying today and then having some big frosts in two days’ time can also be fraught with potential cereal or legume crop damage.
So here is another issue to consider for those farmers and agros looking at weed spraying the crops we have and dodging these heavy cold events that put more pressure on our few winter crops that are in our region.
It is a very tough cropping period... again.