Scottish farmers say they've suffered some of the biggest losses in food crops the industry has ever seen as a result of the weekend's flooding.
NFU Scotland said millions of pounds worth of unharvested vegetables have been damaged by flood waters described as unprecedented for the time of year.
The union says tight profit margins mean many will not be able to absorb the significant losses.
The full impact won't be understood until flood waters fully recede.
But some individual farmers have reported losing whole fields of vegetables worth hundreds of thousands of pounds.
NFUS president, Martin Kennedy, said: "There's a lot of crops still in the ground that still have water over the top of it so a lot of it will be lost. We're talking about potatoes, broccoli, turnips - very high-value crops that are still to go into supermarkets."
He accepted that farmers are used to the weather affecting production levels but said that losses were "very, very difficult to bear the brunt of" because of the scale of the flooding experienced.
Efforts are under way by the farming union to try to count the losses, but its expected to take several days to see the full picture.
The area with the largest impact is thought to stretch from Inveraray in Argyll through central Scotland almost to the east coast.
The union has called for immediate help from the Scottish government and longer-term discussions about the burden being spread across the supply chain.
Stewarts of Tayside estimates that about half a million pounds worth of food crops destined for supermarkets have been ruined across 60 hectares of its land.
That equates to about 2,000 tonnes of food from swedes to strawberries and potatoes.
Managing director Liam Stewart said they experienced a low yield last year because of low rainfall, then had to delay planting in the spring because the ground was too wet.
He said: "There's body blow after body blow and farmers are no longer growing the same amount of buffer as they traditionally would, so if something grows wrong we take the hit."
"The cost of growing crops now is so high that you can't grow in the hope you'll sell it.
"We need everything to happen, otherwise it's the difference between making money and not making money."
Scottish government rural affairs secretary, Mairi Gougeon, said: "The rainfall we have seen over Scotland this weekend has been extreme, affecting many communities and businesses.
"We are engaging with the sector to determine how much they have been affected and what the implications of that are.
"Once we have the full picture we will explore what can be done to help those affected."