Victorian farmers have their state government's blessing, but are awaiting federal government approval.

And as Tasmanian growers wait to see what happens across Bass Strait, Poppy Growers Tasmania chief executive Keith Rice said that it was really a matter for the UN.

"The federal government has indicated it would be happy for a managed and controlled expansion onto the mainland, but is yet to renegotiate the 1971 Intergovernmental Agreement, under which commercial growing was restricted to Tasmania," he said.

"Under this agreement, export of poppy product from Australia was quarantined to what was grown in Tasmania.

"Our position is that there is no need for mainland expansion at the moment because the market has decreased since 2012 and there is area available here to expand.

"We understand the need to continue with trials on the mainland, even commercial trials up to 200-300 hectares, to satisfy international customers that, if the need arose, any increase in demand could be met as required."

Mr Rice said that poppies were not a normal commercial crop and could not be treated as such.

"Even the UN has said that it does not want to see a proliferation of growing sites," he said.

"Tasmanian Alkaloids and GlaxoSmith Kline have given commitments that Tasmania is their home ground and anything going to the mainland will be a risk mitigation strategy — Tasmania will remain their home base."

Mr Rice said that while Tasmanian poppy growers understood a potential future need to grow product on the mainland,they "totally opposed" the import of material from overseas.

"Clearly the downy mildew issue will seek to reinforce that opposition," he said.