Alerts out for frost damage

The advanced growth of crops throughout the State has increased the risk of frost damage.

Grains Industry Association of WA Crop Report for author Alan Meldrum said frost was now the highest risk for crops in the southern districts, with crops at head emergence to flowering far earlier than in normal seasonal conditions.

Frost was also a risk to the south Geraldton area where frost was rarely a threat.

“Mid-season maturing varieties of wheat, such as Mace sown in late April, are now at head emergence to early flowering, and have heightened susceptibility to frost damage as a consequence,” he said.

Department of Agriculture and Food WA research officer Ben Biddulph said there had been several frost events in the region during the past fortnight which could result in minor impacts on crops.

Some localised areas recorded temperatures as low as -2C to -4C that would result in frost damage, most from the nights between August 1 and 2 in the central, eastern and Upper Great Southern agricultural region including Quairading, Bonnie Rock, Narembeen, Hyden, York, Beverley, Wickepin and Narrogin.

In some regions which experienced rain in the evening beforehand, there has been localised reports of stem and reproductive frost damage in canola, wheat, barley and lupin crops at susceptible stages, in susceptible parts of the landscape and soil types.

A series of milder frosts with minimum temperatures of -1C to -2C also occurred in agricultural areas in the northern Wheatbelt, Lower Great Southern, Lakes Districts and Salmon Gums.

“Growers should be looking for symptoms of damage in crops which will become visible over the next week,” Dr Biddulph said.

“When damage is clear, management and salvage options can be considered carefully.”

Frost symptoms may not be obvious for up to 10 days after a frost event. The damage tends to be patchy with variability within a paddock.

Dr Biddulph said early-sown crops, low-lying areas and light- coloured soil types were usually most at risk and these areas should be checked first.

“Growers must be confident about damage levels and consider a range of economic aspects before making decisions about damaged crops,” he said.