About 12 citrus orchards in the Gayndah area in Queensland's southern inland have lost 85 to 100 per cent of their crop to hail damage.
Storms swept through the area on Tuesday night and also damaged some homes.
Judy Shepherd from the Gayndah Fruit Growers Association says about another 10 orchards suffered damage to a lesser extent.
"Trying to work on values, get some figures at the moment but it's a very significant amount for next year's market," she said.
"[We are] looking at about 30 per cent of the crop size in the Gayndah area alone for next year.
"We've all, most of us, spent a lot of money getting it to this point - it's especially heartbreaking, it really is.
"It's very difficult to mitigate the losses from the crop at this time."