Ministry for Primary Industries staff have put the brakes on a new product which some kiwifruit growers are heralding as a cure for the bacterial vine disease Psa.
Yeti F is being imported from Italy labelled as a fertiliser, but growers in the Bay of Plenty have been using it to battle Psa by injecting it directly into the stumps of ailing kiwifruit vines.
Te Puke grower Rob Thode said it has made a spectacular difference to the health of his orchard, with new and healthy shoots growing on previously sick vines.
However the ministry says this practice must stop.
The company importing the product, Perazim Technology, has been told that trials must wait until the product has been given provisional research approval.
However the Ministry for Primary Industries is allowing one trial to continue as it is in a contained glasshouse. Results are expected to be provided next month.
The Ministry said Perazim Technology was allowed to import Yeti F as a fertiliser but when it began trialling the product against Psa it breached the Agricultural Compounds and Veterinary Medicines Act.
It said it is important there are controls of the use of chemicals on food crops so New Zealand can assure domestic and international markets of the safety of its products.
Yeti F was trialled last year on 25 hectares of badly affected vines. The fertiliser was mixed with silver compounds, with small amounts of copper and iron.