Kiwifruit growers are preparing to spray their vines with antibiotics, in an unprecedented attack on the rampant Psa fruit disease.

Psa has infected 27 new vineyards in the past week.

The Pesticide Action Network warns human health could be affected by the antibiotic spray, but the Kiwifruit Vine Health board says it is an urgent and temporary measure.

KVH and grower-owned kiwifruit marketer Zespri are planning applications of Keystrepto, a product containing the antibiotic streptomycin, used to treat tuberculosis and the plague.


The antibiotic is due to be applied by the end of next week, sprayed by ground-based machines before flowering to stop any fruit becoming contaminated.

The European Union, a major kiwifruit export market, places zero residue tolerance on fruit. The spray will be restricted to growers in the priority zone around Te Puke and in high-risk areas in the wider Bay of Plenty.

Debbie Morris, the Agriculture Ministry's agricultural compounds director, said Keystrepto had already been regulated for the treatment of fire blight on other fruits. But Pesticide Action Network's Dr Meriel Watts said the Food Safety Authority has found growing streptomycin resistance in E.coli bacteria in dairy calves. "We have a pool of bacteria developing resistance," she said. "If we spray it on kiwifruit vines ... sooner or later it will become a problem in humans. It's a crazy idea."