Wow - the arrogance of regulators to decide which potatoes farmers can sell. FFS 

In answer to your question, the following is from the article:

How a potato becomes decertified

The B.C. Food History blog, which is run by a group of university lecturers, says the Cariboo potato was developed by the federal Potato Research Centre in Fredericton, N.B., and did "unusually well" in the B.C. Interior's tough climate during the 1960s and '70s.

Diether says that, despite the potato's hardy nature, its thick vines and feathery foliage made it unsuitable for mechanical harvesting, as the vines would tangle with machine pickers.

He added the Cariboo potato was also sensitive to sunlight, which would make the spuds go green if they were sitting on a supermarket shelf for long.

The blog says the potato was "decertified" by Agriculture and Agri-Food Canada (AAFC) in 1976, which meant that commercial potato seed growers would lose their licence if they continued to grow them.