Production of some food could become a casualty of the campaign against Covid-19, the horticultural industry says.
The industry said it strongly supported the fight against the disease, but no one should be blind to its real costs.
These included the risk of some growers quitting the business for lack of markets and workers, thereby reducing New Zealand's food supply.
The comments come in the wake of a desperate plea from a Northland producer Brett Heap who grows zucchini on 30 hectares near Kerikeri.
He was an early pioneer and long-standing supporter of the RSE scheme because, he said, he could not get New Zealanders to do the back-bending work of picking his crop.
Heap said he worried about paying big money for fertiliser to plant in winter and harvest in spring because RSE workers might not be available at that time.
That would leave a lot of sunk costs that might not be recovered, so an entire year's crop might not be planted - and a year's income could go down the drain.
The government has ruled out any relaxation of rules banning new migrant workers.
Immigration Minister Iain Lees-Galloway said the border was closed and would stay closed for a good reason.
He could not say when that border might reopen.
In the meantime, New Zealand businesses may look to New Zealand workers or redeployment of RSE workers who came into the country before the lockdown.
Horticulture New Zealand chief executive Mike Chapman said with or without the coronavirus, New Zealand had no real strategy on providing food security for its people, and that had to change.
He said he understood the minister's position and Covid-19 had to be fought, no question, but there were serious implications for growers.
"We need to develop ways in which to give growers certainty so they can plant their crops and give a secure supply of food to all New Zealanders."
"We don't know whether borders are going to reopen or not, we don't know if we are going to get on top of Covid-19 or not," Chapman said.
"Growers of vegetables who are making planting decisions, growers of strawberries who are making planting decisions, need to think about whether they have somewhere to sell their produce and will they be able to get the labour they need," Chapman said.
He said there was another problem: under both level 4 and 3, restaurants, farmers markets and other outlets were closed to growers' output.
"If you have got nowhere to sell, you don't plant, and so some growers would think, why would I remain in this industry?"
RNZ
