New South Wales has ordered a temporary ban on all citrus produced in the Northern Territory — a move that could be replicated across the country — after the devastating citrus canker disease was detected in Darwin.

It is believed three citrus plants sold from a Darwin nursery and three from a Palmerston nursery were infected with the contagious plant disease, which was uncovered last week.

Citrus canker destroyed more than half a million citrus trees in Queensland 14 years ago, and Citrus Australia warned the latest outbreak could impact trade.

The NSW Department of Primary Industry has since enacted a control order, banning all citrus from the Northern Territory, including plants, fruit and leaves.

Acting Director of Plant Biosecurity and Product Integrity Chris Anderson said the order was "necessary to prevent the biosecurity risk" in New South Wales.

The ban will remain in place for 18 months, or until it is revoked.

"There's not a lot of commercial stuff that comes out of the Territory … it's very much precautionary at this stage," NSW DPI deputy director general of biosecurity and food safety Bruce Christie told the NT Country Hour.

"There's national meetings going on at the moment. I understand that NSW and Victoria have already put in place orders.

"Queensland, South Australia, Western Australia are also looking at doing something similar."

States, territories 'agree to restrict movement'

Citrus canker destroyed nearly 500,000 orange, lemon and mandarin trees in Emerald. ( ABC News: Elias Clure )

The NT Department of Primary Industry spent the morning meeting with local citrus growers.

Citrus Australia said the number of plants tested and found to be infected with citrus canker had "increased slightly" since last week, but were contained to the same nursery.

"There's been no trade to commercial citrus producers, and that's a positive in what isn't a great situation to be in," Citrus Australia CEO Nathan Hancock told the NT Country Hour.

"Last week there was a meeting of the domestic market access representatives for each state and territory, and they agreed to … restrict the movement of material temporarily.

"For Northern Territory growers it means they can't trade out of the state."

Mr Hancock said all state and territory representatives who attended last week's meeting had agreed to implement a ban, and though it may be "in process in their [state's] legislation", the trade of plant material out of the Northern Territory had been "effectively banned".