Severe frosts and a cold spring in the United States have damaged wheat crops and delayed corn planting.
The poor weather is threatening to slash American yields and increase the demand for Australian grain.
Market analyst Arlan Suderman, from Wichita in Kansas, says global grain prices will rise if poor conditions linger in the US.
"If the pattern holds for several more weeks, then we could be looking at a much more substantial reduction in acreage," he said.
"(This) would dramatically impact the global feed grain balance sheet and probably lead to much sharper global feed prices."
© ABC 2013
16:38 EST Organisers of the Mulga Bill Quick Shear at Yeoval, in Central West New South Wales on the weekend, were a bit nervous about the weather on Saturday morning; there'd been good rain on Friday night and they didn't have a 'Plan B' if things didn't clear up.