The range of organic vegetables available in Australia would shrink and hundreds of organic businesses be devastated under federal government plans to change import rules, the industry has warned.

The Department of Agriculture and Water Resources has proposed compulsory fungicide treatment on a host of vegetable seeds entering Australia, saying increasing globalisation of the vegetable seed trade, among other factors, has brought a heightened risk of pathogens entering the country.

Andrew Jones of BurraBee Farm in NSW said the proposed changes would "kill my business".

The changes would apply to some brassicaceous crop seeds including broccoli, cauliflower, kale, rocket, cabbage, turnips, bok choy, brussels sprouts and radishes.

Australia is almost totally reliant on imported vegetable seeds. However seeds treated with fungicide would not be considered organic, meaning the range of organic or pesticide-free vegetables grown in Australia would fall dramatically under the proposal.