WEIGHING UP PLANTING DATES
WE ARE hopefully at the end point of any more severe, or even medium, frost events in much of our winter crop-growing area.
These winter cereal crops’ susceptibility to frosting events is a real compromise with respect to sowing date, with potential high temperatures at grain fill limiting grain development on one side and on the other hand, having the head emergence and flowering in among sub-zero temperatures.
Our winter crops have had enough of a beating with frost and dry weather this winter as the picture depicts, and these latest chilly conditions are really not required.
I know that the early April rain did a great job setting up our subsoil moisture levels for our impending winter crop and even for this coming summer crop.
Unfortunately, it created an earlier planting date that most of us would have preferred not to have.
Early plantings are excellent for extensive root development, for plant bio mass to be increased and maximised, while also providing longer grain fill time in cooler conditions.
And warmer soils at planting time usually deliver a better seed strike and plant establishment. All good points for yield and protein maximisation.
The downside is the risk of frost.
Many will say that more yield is lost through late plant dates, but while later plants may have a lower yield goal, you are at least faced with zero risk of a frost wipe-out on your wheat, barley and chickpeas.
Later planting dates may give us comfort on those icy mornings, when our wheat is still at elongation or flag leaf time, however I believe looking at frosted cereal and chickpea crops is a tough job all round.
Alternatively, face the reduced yield possibilities, which become more of a concern for these later plant dates.
Both are very old arguments and have been discussed by neighbours for years when setting up the planters for winter crop sowing.
So what to do for next year?
It must come back to variety selection, initially, and your own local experience from previous years for a planting date.
I acknowledge we had extremely warm weather until the end of June and the cereal crops really bolted, however when faced with these early soil moisture levels, you may also need to plant a variety that fits the time on the calendar, rather than what’s in the silo.
There is plenty of GRDC research occurring into mitigating the effects of frost, including frost effect-reducing chemicals, and my favourite is looking at possible nutritional elements in potassium and copper, plus other useful tools.
I believe our big advancement will be genetics and at this stage that just means germ plasm imported from around the world giving us security of yields in most of these challenging frost or warm spring years.
Until genetic modification becomes accepted by the world markets we are going to face this double dilemma of frost on one hand and warm spring conditions on the other.
I know which problem I would prefer to inspect each year and it is not turning wheat and barley crops into hay.
The argument of planting dates lives on for our winter crops, just like the argument we are all having now with warming soils and sorghum or millet planting.
To do or not to do is a very quotable quote right now.
That’s all folks.