The Art Gallery of South Australia says its $4.5 million purchase of a landscape by French Impressionist painter Camille Pissarro is the gallery’s most significant ever acquisition.

The purchase figure for Prairie à Éragny (1886), bought at Sotheby’s Impressionist and Modern Art auction in New York, is more than double the highest amount previously paid by the gallery for a single artwork: JMW Turner’s watercolour Scarborough Town and Castle: Morning: Boys Catching Crabs (c1810), which was bought for $2 million in 2006.

Announcing the Pissarro acquisition this morning, gallery director Nick Mitzevich described Prairie à Éragny (1886) as a “quintessential French Impressionist landscape – full of vitality and colour”.

“Painted at a defining moment in Pissarro’s career, Prairie à Éragny will enrich the gallery’s Impressionist collection, introducing a wonderful example of French Impressionism into the collection which has strong holdings of British Impressionism,” he said in a statement.

The gallery has been working on acquiring the painting for more than 18 months. Most of the money was provided by private donations, together with the James & Diana Ramsay Foundation, with a further $100,000 still being sought through further fundraising.

Prairie à Éragny will be unveiled at the gallery on August 22, and will go on public display in the Melrose Wing of European Art from August 23.

Pissarro is described as a defining artist of the French Impressionist and Neo-Impressionist movements, with this particular landscape introducing the new Neo-Impressionist style that he helped to pioneer.