Prime Minister Scott Morrison announced the visa changes today, effective immediately, at a strawberry farm in southern Queensland as part of a four-day tour of the state.

The changes are designed to keep workers on farms for longer.

They are in response to widespread calls for a solution to the shortage of farm labour, and after grower groups criticised the Prime Minister's earlier proposal to engage unemployed Australians to fill the gap.

Under the relaxed rules, Pacific Islanders taking up seasonal work will be able to stay three months longer, and the age limit for working holiday visas for some countries will be lifted to 35.

Backpackers will no longer need to leave jobs every six months, and will be able to triple the length of their stay if they do extra agricultural work.

Mr Morrison said the changes would help farmers and growers get access to the labour they needed to ensure their businesses could be successful.

But he said his view regarding finding Australians to do the work had not changed.

"We need to ensure that we get as many Australians into these jobs as we possibly can," he said.

"But we also have to make sure that we actually get the job done."

Changes demonstrate Government 'taking concerns seriously'

Horticulture lobby group Growcom said the visa changes were a welcome relief but not a solid long-term solution.

"I think they're a fantastic first option on the table and they demonstrate that the Government is taking our concerns about our labour force seriously," chief advocate Rachel Mackenzie said.

"It will enable those backpackers who want to work in agriculture to have the capacity to work in agriculture and also stay longer."

But Ms Mackenzie cautioned against an expectation that the changes would lead to a significant increase in farm workers coming to Australia.

Backpackers who work on a farm are currently limited to a six-month stay, but Ms Mackenzie said that would now be changed to being able to stay on a single property for a year.

"That's of particular importance to some broadacre farms, particularly in the NT. They really need good workers to stay," she said.

National Farmers' Federation president Fiona Simson said the visa changes were a huge step forward.

Increasing the age limit for backpackers from several countries from 30 to 35 years was consistent with the feedback farmers had received, Ms Simson said.

"People are still backpacking now in their mid-30s and are quite happy to go out on farm, experience regional Australia, work hard for a couple of months and then keep travelling," she said.

The changes also shift some of the upfront costs for the seasonal worker program from employers to employees, but Ms Simson was not concerned this would put undue burden on workers.

"This is not about trying to take money out of the pockets of seasonal workers. This is actually about recovering some of those upfront costs that farmers have to pay," she said.

"This is about matching up farmers with employees in a way that is reducing some of the costs for employers, while giving seasonal workers a lot of options to come on farm."

More lobbying to improve options

But Ms Simson said the industry would continue to lobby for a dedicated agriculture visa to include more changes, including around the portability of a seasonal workforce.

"The seasonal worker program is still attached to a single employer, so an employer signs up for an employee or a number of employees to come for a period of time," she said.

"What we know is that in some districts of Australia, that whole district enters a period of picking for a number of months and that the district moves on from, say, citrus to stone fruit to grapes to vegetables.

"Over that period of time, it might be possible for workers to move from employer to employer, and so we think that an ag visa would be able to target that portability issue a little better than some of the current options we have on the table."

Changes will make a difference for backpackers, businesses East Bundy Backpackers owner Brian Sparkes said the changes were "fantastic".

"I think it's great for the local community. Not just the farming community but local businesses, shopping centres, restaurants, pubs, retail stores," he said.

"A lot of them [backpackers] would like to be here long-term. As in, more than just a one-year working visa.

Mr Sparkes said if backpackers were allowed to work longer for someone they trusted, they were less likely to be exploited.

Netherlands resident Anna Stoepman, who has been in Australia for three-and-a-half months, said she had finished her 88 farm work days towards her second-year visa, but would stay longer and work on the farm.

She said she hoped the changes would create more opportunities for people wanting to stay in the country. "I think for a lot of people it just opened doors. Perhaps people can get a sponsorship more easily," she said.

"It will really help backpackers who don't just do it for the days, but because they like the work and the experience. In that way I think it will make a difference for backpackers in general."