Federated Farmers national president Bruce Wills said farmers who failed to protect themselves from the sun were paying the price with skin cancer.
"I'm now having melanoma spots cut out as are other farmers I know," Mr Wills said.
He said farmers were an older generation who were never told of the sun's dangers until it was too late.
"It was something we just didn't speak about growing up - no one wore sunblock and there was none of this slip, slop, slap and wrap. It can be hard to break old habits," Mr Wills said.
The study's lead author Associate Professor Tony Reeder said this was a basic health and safety issue for all outdoor workers.
"New Zealand really needs to do better in this regard," he said. Skin cancer accounts for 80 per cent of cancers registered in New Zealand each year. About 2000 of those are melanoma. APNZ