The United Kingdom usually takes about 10,000 tonnes of New Zealand's annual 180,000-tonne export crop of onions - but local growers are worried UK buyers may not want any of our onions this year.
The devaluation of the British pound following Brexit means buyers will have to pay significantly more for New Zealand onions if growers here are to receive similar returns to last year.
Fields around Pukekohe are now striped with rows of onions, gently curing in the sun. They'll soon be heading into the packhouse where they'll be topped and tailed, graded and bagged for export.
But exporter Mike Blake from The New Zealand Onion Company says exporters are still unsure if they will ship to the UK.
"It's quite worrisome for many people in the industry. It'll mean we will be left with product and we'll have to try to redistribute into other markets of the world; places like Hong Kong and South East Asia."
Market gardener Hira Bhana and Co grows 160 hectares of onions a year near Pukekohe in South Auckland. Director Bharat Bhana says in order for New Zealand growers to achieve the same return as last year UK supermarkets will have to pay £125 more per tonne.
"And they've come back to us and said how they can't afford to pay it because they can get old onions from Holland or Spain or somewhere else. (The) quality's not as good. But everybody now wants a price that's level. They don't want the spikes in it any more. Onions is a risky business."
New Zealand's main export market for onions is Germany.
"They like good quality product and they are prepared to pay for it," Mike Blake says.
He was hoping to negotiate a price better than 500 Euros per tonne at Fruit Logistica - this week's huge international fresh produce show in Berlin.