Horticulture New Zealand says there needs to be better understanding about why fruit and vegetables are more expensive at certain times of the year.
The Green Party wants supermarket chains to adopt a pricing code of conduct, after a survey it conducted found the difference between the wholesale and retail price for produce, ranged between 300% to almost 900%.
Horticulture NZ says the organisation does not oppose a code, but an expected shortage of some vegetables due to this week's adverse weather, highlights the seasonality of produce which determines the retail price.
Chief executive Peter Silcock says a lot of the products that are expensive now such as tomatoes, capsicums and lettuces, are not in season now so therefore they will not be cheap. Plus there's not great demand for them in the middle of winter.
Mr Silcock says at times when there's an oversupply of product, those benefits don't always get passed onto consumers by retailers, which is of some concern.
But he says on the other hand, when products are in short supply, the difference between wholesale and retail price is not that significant.