A report predicting Australia's population will reach 36 million by 2050 overlooks the fact that the nation has no plan to feed so many mouths, a Queensland farm lobby group said.

The Federal Government's 2010 Intergenerational Report, released by Treasurer Wayne Swan on Monday, said Australia's population was expected to grow to 35.9 million in 2050 from 22.2 million in 2010.

Peak horticulture body Growcom said the 36 million Australians would need economical, fresh and healthy food supplies.

"There is no national plan in place to guarantee that arable land with suitable water and climatic requirements and adequate infrastructure will be available in the future to guarantee our food supply," Growcom chief executive Alex Livingstone said.

Mr Livingstone said the government's determination to lift productivity was admirable, but ignored the need for investment in infrastructure to provide enough food.

"It is ironic that the report mentions the government's commitment to investing in an improved hospital and health system while ignoring investment in the cheapest form of improving overall health of the population - access to a healthy diet," Mr Livingstone said.

He also said the government should refrain from placing a heavier tax burden on productive sectors such as horticulture, which was an important source of employment and flowon economic benefits in regional Australia.