As farmers prepare to get the headers out of the shed there are fears the Tier 3 rail lines won't be fit to cart grain this harvest.
The Tier 3 lines transport grain from up country receival sites to port and are due to close on October 31st this year.
The train lines were due to close last October but got a 12-month reprieve from the Minister of Transport Troy Buswell, who has ruled out any more state funding for the lines.
Brookfield, which operates the lines under lease from the State Government, has been negotiating the future of the Tier 3 lines with the state's grain handler the CBH Group for more than six months.
President of the Wheatbelt Railway Retention Alliance and Narrembeen farmer Bill Cowan is worried the lines will close before harvest.
"The 31st of October is really a short time away and when Brookfield and CBH have had virtually all year to come to an agreement and still haven't then the 31st of October is looming very close," he said.
CBH is expecting the grain harvest to be up to 13 million tonnes, more than expected after good rains over much of the grain belt.
Mr Cowan says the state's crop has been largely underestimated and it's not physically possible to cart this grain by road without the rail component.
"The bulk of areas within the Tier 3 may be their biggest season ever," he said.
"It's right up there with the best season.
"If we don't have the Tier 3 upgraded, there is no way physically that the trucks can handle the load to take it down to port.
Once the local sidings are full, farmers are going to be devastated. They are going to harvest as well as sending to port."
After a grain trail derailed last week on the Quairading to York line Mr Cowan says it's a sobering reminder the Tier three issues need addressing sooner rather than later.
"You have to remember this could be costing growers up to 6 dollars a tonne," he said.
"It's going to cost us extra.
"For people in the area, who are just about to have their first year to make a profit for many years, that could be costing them $15 million in the Tier 3 area alone."
CBH provided the ABC with a statement, "We are continuing negotiations with Brookfield with a view to an access agreement that would provide us use of the entire grain rail network, which includes tier three."