Australia's melon industry body warns farmers need to be "paranoidly careful" to avoid spreading a disease that wiped out three quarters of the Northern Territory's watermelon industry.

Biosecurity Queensland on Tuesday quarantined a watermelon farm in Charters Towers, west of Townsville, after finding the cucumber green mottle mosaic virus there.

CGMMV is harmless to humans but affects cucurbit fruit species such cucumber, melons, watermelon, zucchini, pumpkin and squash, making it a threat to the state's $130 million cucurbit industry.

It's the second major fruit disease scare in Queensland this year, following the discovery of the Panama Tropical Race 4 fungal infection in Tully and a second case in Mareeba.

Australian Melon Association industry development manager Dianne Fullelove said CGMMV was just as big a danger to the state's $90 million melon industry and other cucurbit growers.

She said the disease wiped out about 75 per cent of melon farming land in the Northern Territory since the first infection was confirmed in September last year and had spread to pumpkins, butter squash and cucumbers.

"It spreads from farm to farm very easily, so once you actually get it in plants, the mechanical transmission is quite easy, on wheels and boots and that sort of thing," she said.

"The on-farm biosecurity is just so important so it's really vital that they do that.

"We wouldn't want workers going from this farm to another farm using the same boots for example, without having them disinfected."

CGMMV creates mosaic-like mottling on affected fruit and can cause the fruit to rot internally, become discoloured, show lesions or become malformed.

Queensland chief plant health manager Mike Ashton said the case appeared to be isolated.

"We are moving quickly and working with the property owner to ensure the infection remains confined at this site," Mr Ashton said.

"We are hopeful the virus is not widespread in Queensland and we will be working to achieve eradication."

BQ believes the Queensland infection could stem from the same crop of seeds they think spread the infection to the Northern Territory.

Mrs Fullelove admitted the disease could be devastating for the industry if an outbreak became more widespread.

"In Israel they have 40 per cent (crop) losses," she said.

"They live with it on their farms and they do lots of practices to try and reduce the effect on their watermelon crops.

"An Israeli pathologist who was out here in January quoted 40 per cent losses and I really don't think growers can sustain that type of loss."

Growers are urged to check their crops and contact Biosecurity Queensland to report suspected cases.

Source - http://www.brisbanetimes.com.au/