Mr Little, a Forth-based vegetable haulage contractor, stands to lose about 20 per cent of his business next year and yet he says he got off lightly.

"The flow on effect of this is going to be absolutely massive and just devastating for a lot of people," Mr Little said.

"A lot of contractors have invested heavily in machinery and equipment, in harvesting gear - and many of these guys are growers too - but next year they've got no contract to fill, no crop to harvest."

Mr Little started his own company, Little Transport, 27 years ago, carting vegetables exclusively out to McCain. He now has 16 trucks, four of which haul peas, beans, cauliflower and broccoli to Smithton.

"I heard about the closure on the news on Friday and I'm still trying to get my head around how I'm going to find the business to replace McCain's," Mr Little said.

"And the thing is, if the Government does not step up to the mark and gets some import duties in place so we can compete with overseas vegetables, then Simplot will be the next one leaving."

Simplot, with processing plants in Devonport and at Ulverstone, has been the focus of much speculation surrounding its future in the state, whether it could handle any extra supply and how its new-found monopoly will affect farmgate prices.

The company has not been commenting.

Sassafras farmer Scott Elphinstone, a McCain grower, said that he would be trying to supply vegetables for Simplot next season, well aware he would be one of many.

"But things in general don't look particularly rosy right now," Mr Elphinstone said.

He said that news of the McCain closure was not completely unexpected and its impact was dulled by the company's recent contracts.

"We've already suffered the massive cutbacks - they hit us with them this season - so we're already down the path of diversification."