Heinz Watties has stopped purchasing New Zealand-grown asparagus in favour of cheaper Peruvian product.

The decision affects up to 15 growers in Hawke's Bay and several in the Rangitikei. Growers elsewhere sell all their asparagus fresh on the domestic market or to Japan.

About 3000 tonnes of asparagus is produced in New Zealand a year, of which 2500 tonnes is sold domestically, 300 tonnes, goes to Japan and the remainder is canned. "It will have a significant impact on growers, removing an outlet for them to sell their asparagus, and creating a possible oversupply in the domestic market," New Zealand Asparagus Council chairman Tony Rickman said.

Heinz Watties said it had always been "second choice to fresh" in the asparagus market. In a competitive market it never made sense to buy ingredients at a price that left the company uncompetitive. "That is the challenge particularly with asparagus," a Heinz Wattie spokesman said.

"We've imported asparagus for many years to be able to meet demand. The fact that consumers see 'Product of Peru' on the label is that we declare Country of Origin despite local regulations not requiring us to do so. Being transparent seems to work against us."

Heinz Wattie said it valued "very much our relationship with growers" and was processing all the peas "we can get our hands on".

Other crops grown and canned in Hawke's Bay include carrots, peas, beetroot and sweet corn.