Farmers in South Australia's Mid North and Southern Flinders Ranges are reporting the worst frost damage to crops in recent memory.
Agronomist Matt Foulis says some growers could lose up to 90 per cent of their crop and are now considering cutting early for hay.
He says a week of temperatures below zero caused stem frost in plants that are now starting to rot.
"I've spoken to growers around the district. Some of them have been up here all their lives and have never come across it.
"I think a couple have had minor frost at flowering and those sort of things, but to cop this more severe stem frost is a completely new thing in our area."
Mr Foulis says a run of freezing temperatures could have caused the damage.
"I think we had a week of -4, or thereabouts, and it's taken its toll and we have unfortunately copped this stem frost."
John Carey farms between Wilmington and Melrose and says frost has potentially damaged up to 90 per cent of some of his paddocks.
Farmers and agronomists met at his farm this week to inspect the crops and discuss options.
He says damage may be severe enough to cut it for hay rather than trying to harvest any grain.
"I wanted a show of hands from the 70-odd chaps out in our paddocks as to whether we cut it and they didn't really say that.
"But it probably looks the best option for this paddock to be cut, because there would be very minimal grain to be harvested, from some of the assessments."
© ABC 2014
15:02 EDT South Australia is enduring one of its longest dry spells in years and despite cloud moving in from the northwest today, significant rain relief is a long way off.