Prosecution of kiwifruit growers who used antibiotics illegally on their vines is still possible.

A spokesperson for the Ministry of Primary Industry says investigations into the misuse of the product KeyStrepto by some growers is still under investigation.

Around 50 growers are currently under investigation, not all of them for injecting the antibiotic into plants.

'MPI continues to reserve the right to prosecute growers where that course of action is appropriate. Prosecution is not off the table. MPI approved the application of KeyStrepto and stipulated strict terms on how the antibiotic could be applied to kiwifruit vines.
'That said, MPI did clearly signal to growers that full voluntary disclosure of misuse of streptomycin would be taken into consideration when considering consequences,” the spokesperson says.

Around 50 growers are currently under investigation, not all of them for injecting the antibiotic into plants. A number are involved because they were unsure if their vines had been affected by spray drift from other orchards.

The growers who injected their vines volunteered that information to Zespri before harvest, and their fruit has been stripped from the vines and mulched.

Had they not owned up and attempted to sell the fruit the legal consequences would probably have been more swift and severe. The ministry says that under the Agricultural Compound and Veterinary Medicines Act (ACVM) 1997 it is an offence to sell produce that has been mistreated with an agricultural compound.

Growers who injected mainly male vines with Keystrepto did so in a desperate attempt to save them from the aggressive disease Psa-V, which has killed thousands of gold kiwifruit vines since it was first discovered in New Zealand in November 2010.

Zespri chief executive Lain Jager says each of the 50 growers involved had no intention of harming the Zespri brand or fellow growers by their actions.

However, the fact the antibiotic had been misused has cost the industry around $1.5 million to carry out 9000 tests on 3000 orchards to ensure there are no traces of antibiotics in fruit.

'We tested each orchard three times and have also carried out tests offshore and have not found any residues.”

Markets had questioned Zespri after TV One aired stories about the antibiotic use, but Lain says the company's assurances have been accepted and there have been no negative reactions in the markets.

Whether or not the growers will be prosecuted is out of the hands of Zespri as that is the domain of MPI.

However, Lain says the growers involved have already suffered from losing their crops and income for this season.

Meanwhile, Psa-V continues to infect vines with seven new cases reported in the last week bringing the total of orchards with the disease to 1218.