The company's rural supplies manager, Grant Bunting, said management was working with those made redundant to find other positions within the company.
Mr Bunting said the lease on the building on the corner of Vogel and Gordon Sts in central Dunedin expired in late May, which contributed to the decision. The store will close on April 22.
Store patronage had also declined.
"We have noticed that rather than travel to the city centre, customers are now trading closer to their own farms and businesses, and the numbers coming through the store have steadily dropped away."
The company has rural supply stores at Mosgiel, Outram, Milton and Palmerston.
PGG Wrightson's Otago district manager Grant Edwards said as well as having access to a rural supply store network throughout the province, farmers had fewer reasons to visit cities.
Business for which they once had to come to town was now conducted by professionals visiting them in their home, over the phone or by the internet.
He had spoken to farmers who used the store and said they understood the need for the company to make such business decisions.
