Australian horticulturalists have said the recent poisoning of about 4m tomato seedlings and 2m capsicum seedlings is an example of industrial sabotage, the ABC has reported.
Police believe a herbicide was put in the irrigation system used by two nurseries at Bowen, in North Queensland, around 10 days ago, and they have launched a major investigation into the incident.
"That's the view of the police - that it's been deliberately sabotaged," said Carl Walker, a spokesman for the Bowen District Growers Association (BDGA).
"We don't like to think that someone inside the industry has done this deliberately to try manipulate the price.
"Anything could be possible - `police are` chasing every single lead they can at the moment, which is really good."
Mr Walker said as much as 350 hectares of growing land could be lost because of the poisoning.
Queensland primary industries minister Tim Mulherin said the attack will be a major setback for more than 30 growers this tomato season.
"It has a knock-on affect, not only for the Bowen district, but also for the price of tomatoes, zucchinis, pumpkins, melons and eggplants," Mr Mulherin said.
Communications manager with peak body Ausveg, Hugh Tobin, told Fruitnet.com that at the moment things were normal in the market, but said prices in September could almost double.
"At the moment it's business as usual but there will be three weeks in September, when those seedlings would be coming to market, the prices will increase," Mr Tobin said.
"This sabotage could cost the Bowen economy as much as A$23m (US$19.9m), and with the flow on effects, it could be as much as A$50m (US$43.26).
"To put it in perspective, 80 per cent of Australia's tomatoes are coming out of the Bowen region at this time of year."
Mr Tobin said it was particularly concerning that the poisoning was not an isolated incident.
"This is the fourth incident in eight years, and it's disturbing that someone is repeatedly targeting this region.
"Police are saying it could be a disgruntled worker, or someone else may be trying to control the market, but it's all just speculation at the moment."