Lemon producers in California have filed a lawsuit against the US Department of Agriculture (USDA), over a ruling allowing lemon imports from Argentina.

The US Citrus Science Council, which represents around 750 of the country's lemon farms and has launched the legal move, said domestic producers fear the USDA's decision risks introducing plant disease and pests to domestic lemon crops.  

The USDA said last December that it would drop its 16-year ban on Argentine imports, but issued a 60-day stay on the decision, which was subsequently extended by a further 60 days. The new rule takes effect on 26 May.

The lawsuit claims that proper procedures were not followed and that when the USDA visited Argentina last September, it was at a time when the Argentine citrus industry was in a "dormant stage". That meant the USDA would not have been able "to make an informed assessment as to the harvesting and packing practices of the South American citrus growers", the lawsuit claims.

Joel Nelsen, president of California Citrus Mutual, said: "If you start allowing shortcuts to be taken now, how does this affect other import petitions from other countries from pest and disease-infested areas?"

Nelsen said he hoped the dispute could be resolved within the next 12 months, although he acknowledged this was "entirely dependent on the court".

The first hearing into the lawsuit will be held in July.

Earlier this month, the US and the EU signed a deal under which the rules on US citrus imports to the EU were amended, including dropping a requirement that US groves be surveyed for citrus canker.