Mr Verry said if as few as 10 stallholders were to leave the Farmers' Market in favour of the growers' market "it would severely compromise us".
Earlier Mr Verry wrote to Hastings Mayor Lawrence Yule, saying the 14-year-old market had "struggled in recent years with high cost".
Stallholders were concerned that Hastings could not support two large markets as well as the association's Thursday night market, Black Barn's Saturday Growers' Market in summer and various smaller markets.
"We understand the interest of the CBD retailers to promote the CBD and relate strongly to the problems afflicting retailing generally - we are in that same space," Mr Verry said.
In his submission, he said dual stallholders experiencing success on Saturdays in the CBD were a threat to Farmers' Market sustainability.
"The unseen risk is stallholders running out of produce on any given day and simply not turning up to the Farmers' Market the next day," he said.
"This would strike at the heart of the consistency that Hawke's Bay Farmers' Market provides our customers and prides itself on. If we can't offer a consistent supply of produce, local customers will shop elsewhere as our relevance is diminished."
Hastings City Business Association chairman Michael Whittaker said about 30 Farmers' Market stallholders wanted to also participate in the growers' market, which was "a fantastic result" because it gave Farmers' Market stallholders "a significant additional sales opportunity".
Black Barn events manager Francis De Jager also submitted on the road closure.
"This is further example of continued dilution of community resources by individual organisations pushing their own barrow without the thought, support or dialogue with existing successful Hastings District and Hawke's Bay event stakeholders, namely markets in this instance," he said.
"I don't see how a Saturday market will increase shopping in the CBD when the Thursday market doesn't and is basically a collection of food vendors. To me, this would only create chaos for shop owners.
"What the CBD needs is shops that people are attracted to and wish to shop at, not a recreation of a great Hastings Sunday market, already in a beautiful location, in the CBD. It doesn't make sense."
Mr Whittaker said the growers' market was modelled on the Whangarei Growers' Market.
"It has a huge benefit to that local community," he said.
A recent study said its $3.66 million turnover created an additional $5.84 million of activity for the Northland economy and was responsible for 112 jobs and 69 per cent of market attendees shopped elsewhere in the city before going home.
It found the social impact significant. Customers appreciated the atmosphere of the market, its "community building nature" and its benefits for local retailers. Fresh produce provided "a vital component of the local health network".