Frank and Margaret Brenmuhl were involved in a head-on collision on State Highway 73 at Kirwee about 9.30pm on Thursday last week.
Margaret died at the scene and Frank was taken to Christchurch Hospital in a critical condition, but died the next day.
The Brenmuhls moved to Hinau in the upper Grey Valley in 1984, where they had a dairy farm.
Mrs Brenmuhl was a teacher at Sacred Heart School in Reefton, while Mr Brenmuhl held leadership positions with Federated Farmers West Coast.
In 2005, he was elected as chairman of Dairy Farmers of New Zealand, and six years later put his name in the hat for national Federated Farmers president.
The couple left the Coast in about 2007, relocating to a walnut orchard they had developed near West Melton.
Mr Brenmuhl also served a term as president of North Canterbury Federated Farmers.
Mai Mai farmer Graeme Neylon said the Brenmuhls milked 220 cows at Hinau, and also bought and developed another farm over the road.
"(Margaret) was a very, very nice lady, real hard worker. She did a heap on the farm as well as teach every day."
Frank had the "gift of the gab," Mr Neylon said.
Atarau dairy farmer Paul Berry served on Federated Farmers with Mr Brenmuhl.
"Frank had his own way of saying things, he was out in the open.
"It's a tragedy."
Reefton school teacher Tony Fortune described the couple as "fantastic people and great friends".
Mrs Brenmuhl also taught with him at Inangahua College.
Their funeral will be held on Monday at St Joseph's Catholic Church in Darfield.
