Wet weather has wiped an estimated $A500 million off crop values in New South Wales.
Parts of the state are now declared natural disaster zones.
The ABC reports farmers had been expecting a bumper crop following good conditions in the spring.
But values have now dropped significantly as the rain continued to deluge regional centres into summer.
"This is simply devastating to farmers who after 10 years of drought will now see one-sixth of their crop lost to rain," said NSW Emergency Services Minister Steve Whan.