Speaking at a Forth vegetable farm on Saturday as it poured rain, federal opposition leader Bill Shorten said if elected his government would spend $100 million to fund the third tranche of the state's irrigation scheme. 

Since 2010, Tasmanian Irrigation has modernised and built on the inter-connectivity of the state's irrigation networks over several projects in the first and second tranches.

Mr Shorten said that despite Tasmania making up just one per cent of the country's landmass, the state received 13 per cent of Australia's annual rainfall. 

"What that means is that we're not capturing all the water which comes during the rain, and not using it for irrigation," Mr Shorten said.

"Tasmanian ag at the moment is about $1.5 billion dollars.

"But in the next 20 years if... we put in the airport links to go to Asia, and we get the irrigation going, it's going to be a $10 billion plus industry. 

"This is Labor committing itself to be the party of farmers and agriculturalists." 

Mr Shorten was joined by Tasmanian Senator Anne Urquhart, federal labor member for Lyons Brian Mitchell, federal member for Bass Ross Hart and federal member for Braddon Justine Keay.

Ms Keay said the irrigation scheme was originally instigated and funded by state and federal Labor. 

"We understand how important these schemes are to transforming the Tasmanian landscape," she said.

Ms Keay said the funding was important for Tasmanian agriculture and farmers and the wider Australian economy. 

Michael Badcock, owner of the Enchanted Isle Farm at Forth where the announcement was made, thanked the ALP for their commitment to the third tranche and irrigation in Tasmania.

"This is a great initiative for governments helping farmers who can help themselves," Mr Badcock said. 

"Having guaranteed water on our farms... allows people to invest and look to the future." 

Mr Badcock said that the development of better export infrastructure should be next on the agenda.

"We are known for producing a very high quality, premium product and the world is requiring this. 

"As soon as we can get direct flights out of Tasmania... you watch Tasmania bloom."