Orchardists and grapegrowers have been told they need a resource consent to fight frost by burning oil in "frost pots" without chimneys.
The Environment Ministry's new national environment standards, which came into effect last week, prohibit burning oil in the open air.
An exception is allowed if the oil is being burned
to protect crops from frost.
But that can now be done only with a regional council resource consent.
Some councils are encouraging the use of smokeless heaters, rather than the traditional frost pots that blanket the orchard or vineyard with smoke.
The nationwide bans on toxic burning that releases dioxins into the air came into effect on October 8, and prohibit the open burning of tyres, coated wire, oil and bitumen and any landfill fires.
High-temperature hazardous waste incinerators are also banned.
In Otago, the regional council has told orchardists and grape growers they can continue burning clean oil to fight frost if the device they use sends discharges to the open air through a chimney or exhaust pipe.
The regional council will permit the use of smokeless heaters if they do not use waste oil and do not emit any discharge that is noxious, dangerous, offensive or objectionable at or beyond the boundary.
The council's director of resource management, Selva Selvarajah, said that previously the council allowed growers to burn cotton waste and virgin oil, but banned burning synthetic fibre or waste oil.
In places such as Marlborough, smoke billowing from frost pots - often drums burning waste oils and oil-based paints - has attracted criticism.
Some vineyards have burned straw bales, and some grapegrowers have burned broken vineyard posts, plastic sleeves and irrigation piping to create heat and smoke.
But critics have said smoke from frost pots adds only a little heat and does not act like a cloud or fog in trapping heat close to the ground. The smoke particles are too small to block longwave radiation loss.
- NZPA
