Kiwifruit Vine Health says it's likely to be only a matter of time until bacteria resistant to copper appears in New Zealand, if disease-fighting tools are continued to be used inappropriately.
Copper sprays and antibiotics have been used to try and prevent the development and spread of the kiwifruit vine-killing disease PSA-V.
Kiwifruit Vine Health chief executive Barry O'Neill says there have been reported cases overseas of both antibiotic and copper resistance to pseudomonas bacteria.
He says in Japan resistant strains of PSA to streptomycin have also been found.
Mr O'Neill says no resistant strains of PSA to antibiotics or copper have been found in New Zealand yet, but Kiwifruit Vine Health wants to make sure everything that can be done is being done to minimise the risk of the bacteria developing.
"We are advising growers to follow label rates and not to go lower than label rates with coppper products so there is less likely changes of resistance developing."
And Mr O'Neill says the concern is that if bacteria that is resistant to copper appears in New Zealand, it will reduce the amount of tools available to prevent the spread of PSA-V.