New Zealand's Ministry for Primary Industries has imposed a temporary ban on Yeti F, an Italian fertilizer that gained recent popularity as an unauthorized treatment for kiwifruit disease Psa.

Controversy arose following media reports that the product, which has not been tested as a Psa treatment, was being used with success to fight the disease by local growers, Kiwifruit Vine Health (KVH) chief executive Barry O'Neil explained.

"It was being marketed as a fertilizer but during our Christmas period, the media picked up the use of the product and a number of media outlets covered the story that it was the cure for Psa," O'Neil told www.freshfruitportal.com.

"In that reporting, the company and growers were quoted as saying it had an effect against Psa. That resulted in the government taking action."

The government has since requested the importer file for a trial license to test the product and has blocked further imports, the executive said.

O'Neil said he knew of a limited number of producers using the product but had received positive feedback, despite lack of approval.

"The growers that are using it claim there have been very positive results and would like to continue using it. We haven’t formally tested the product in our research program and we haven’t done any scientific monitoring to determine whether or not there is any beneficial effect at this stage. So the growers who are using it are making these claims that we haven’t been able to verify," he said.

O'Neil applauded grower innovation but encouraged caution and adherence to set legal standards.

"We have tested 300 products and only really found four compounds that have any beneficial effect against Psa. It’s highly unlikely that there’s a product that’s a single cure. I’m sure we will find more products that are helpful. But Psa is not going to be beaten by a single cure," he explained.

"I think it’s a combination of variety of kiwifruit that are grown. I think it’s a combination of how we manage our vines in the orchard and the orchard location. And I think it’s a combination of the sprays that we put on our vines to protect them against Psa."

www.freshfruitportal.com