Fruit and vegetable wholesalers have been put on notice by Australia's competition watchdog.

The Australian Competition and Consumer Commission (ACCC) has released its report into competition and fair trading in the country's horticulture and viticulture industries.

It revealed late and non-payments by wholesalers, a culture of fear around raising complaints because of retribution, uncertainty about contracts and ineffective codes of conduct are significant issues impacting the two sectors.

ACCC agriculture commissioner Mick Keogh is recommending the removal of the old Horticulture Code of Conduct and imposing new penalties if a party breaches the code.

A report earlier this year found the code needed a major overhaul with 13 recommendations made.

Mr Keogh said the fresh produce markets would have to change the way they treat growers.

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"What is often raised with us, is that there aren't many complaints, therefore the system must be working well.

"Yet when you talk to growers, you get the comment 'well if we raise a complaint, you're out of the system.'

"I think the culture of the whole structure of the fresh produce markets, is one that needs seriously looking at."

The ACCC plans to explore the use of an app that will allow for complaints to be filed anonymously and in a secure way.

Brian Simpson from the Riverina Winegrapes Marketing Board in southern NSW gave evidence at one of the ACCC workshops held across the country earlier this year.

His organisation represents more than 300 growers, some who have reported waiting months to be paid by wineries they supply.

Mr Simpson said South Australia's wine industry had successfully regulated payment terms and he felt the model should be adopted nationally.

"We need regulation in regards to terms of payment.

"It's hard enough growing a crop with all the vagaries of mother nature.

"If you don't get paid on time you can't push your buyer, because you won't have a home the following year.

"These are real issues that growers deal with annually."

Mick Keogh said contracting and competition issues in the viticulture industry would require further consideration by the ACCC's Agriculture unit.

This includes assessing terms in wine supply contracts relating to exclusivity and timing of the release of pricing information.

The ACCC is also looking to promote the potential benefits of collective bargaining, which it believes is an underutilised tool to combat imbalances in bargaining power in both the horticulture and viticulture industries.