"There'll be massive reductions," Mal Peters, president of Australia's largest farmers organisation, the New South Wales Farmers Association, said of winter crops if good rain did not fall in coming weeks.

Planting of wheat, Australia's premier winter crop, normally begins in late April and continues through May. Planting can continue through to the end of June without a loss of yields.

But this will require good rain, which has not fallen for months, while autumn temperatures have soared to record highs.

At stake are some of the world's leading export crops, shipped mainly to markets in Asia and the Middle East. Australia is the world's second-largest exporter of wheat, after the United States, the world's largest exporter of barley, and the world's second-largest exporter of canola after Canada.

All are premier winter crops, and all hang in the balance.

"That is potentially a major problem for us if we don't see some substantial winter breaks in the very near future," Peter Corish, President of the peak lobby group the National Farmers Federation, said on Friday. "If we don't see some rain by the middle of June, we could be looking at a very significant potential drop in grain production, including wheat," he said.

"The potential is there for a situation like 2002 ... We need to see the breaks in the next couple of months," Corish said.

In 2002, Australia's worst drought in a century slashed wheat production to 10 million tonnes from 24 million tonnes the year before, requiring Australia to import the grain from Britain for the first time since colonial days.

Output of all other crops also plunged. Cattle and sheep slaughterings rose dramatically. Farm bankruptcies soared.

"Everyone is watching the sky very closely," Corish said.

Better farming techniques have made the April 25 rule-of-thumb less applicable than in the past, said Grant Beard of the Australian Bureau of Meteorology.

But wheat growing areas had been hit hard by very hot, dry weather that persisted through April, he said.

Two-thirds to three-quarters of Australia had less than one-fifth of the average rainfall for April.

Large parts of the prime eastern and southern grain growing area had had less than 20 percent of average April rainfall, while elsewhere, rainfall had been between 20 and 40 percent of normal.

April temperatures also soared to record highs across half to two-thirds of the country. "It's not just isolated areas, Beard said.

Rainfall broke the 2002 drought in February 2003. But there has not been a single very wet year since to compensate for it, and some areas have struggled on with less than average rainfall, he said.

In March, the government unit the Australian Bureau of Agricultural and Resource Economics (ABARE) forecast a rebound for Australian crops in the growing year to March 31 2006, with wheat seen rising to 22.6 million tonnes from 20.4 million, and barley rising to 7.3 million tonnes from 6.5 million.

That was based on assumed normal seasonal conditions.