A major frost last weekend over the great southern region in Western Australia belted crops. Early reports suggest barley, which was out in head, has fared the worst.
Wheat might have escaped major damage with only small percentage of crops out in head.
It is fair to say it’s still too early to get a picture of the full extent of the damage across crops but according to Grains Industry of Western Australia production losses could be as high as one million tonnes.
After a good winter, crops across WA were flying, but the event during last weekend highlights just how quickly conditions can change.
The size of the WA crop is becoming increasingly important from the points of view of market price and the east coast domestic end consumer.
A number of ships have already transported Western Australian grain from last harvest into the east coast domestic market.
Earlier this month ABAREs forecast total winter crop at 33.2 million tonnes with WA accounting for half.
But as the drought on the east coast expands down into Victoria and South Australia, the reliance of WA grain to make up the domestic shortfall will continue well into next year.
It’s not only the frost event at the weekend that has got the market nervous. The start of spring in WA has been dry.
Analysis of rainfall records indicates it’s the driest September so far across the state’s grain belt since 1939. So what’s the reason for a sudden turn in WA weather conditions?
The BoM recently updated its three month rainfall and temperature outlook for spring, and while it’s no surprise the bias was for continued dryness across much of the east coast, it also suggested WA would also be dry. It stated the major drivers were the potential of both El Nino and/or positive IOD developing.
Now the threat of El Nino developing has been hanging over us all cropping season, and a quick glance of sea surface temperatures in the central tropical pacific leads us to suggest it’s not going to happen.
But there has been a recent development in sea surface temperatures in the Indian Ocean – an imbalance where waters off West African coast have warmed, while cooling over Indonesia and northern WA. In fact the cooler waters have spread right down the WA coast.
This imbalance is called a positive IOD and when it occurs, it enhances the chances of dry weather developing to WA and south Eastern Australia.
The last positive IOD event was in the spring of 2015, resulting in well below average rainfall in September and October.
The WA crop needs a rain to finish them off. Crops in south eastern Australia need a rain to stop the drought progressing further south.
There is still six weeks of the season to go before harvest gets underway, and we are still some way off in getting this year’s winter crop made.
