Copper resistance workshop

KVH continues to work with the science community and agrichemical company experts to better understand copper resistance in Psa.

A science workshop was held last week where presentations on the latest research from Otago University, Plant and Food and Massey University were discussed.

Genome sequencing of Psa samples collected from a range of regions carried out by Otago University has identified two different genome altering mechanisms (Plasmids and ICE) capable of conferring copper resistance into Psa bacteria. These Plasmids and ICE mechanisms are present in other bacteria readily found in the orchard environment and can transfer from these other bacteria to Psa.

We are still working with the scientist to better understand what these latest finding mean when it comes to Psa control on orchards with copper over the longer term, but importantly there is no evidence that the application of copper is resulting in this situation.

Another workshop is scheduled to take place in May to ensure in light of this information we are recommending the best control programmes to recommend to growers.

As a result of these latest findings KVH will be reviewing movement control Protocols for orchards that are known to have these forms of Psa. However other forms of Psa that are deemed a risk to the industry (i.e. mutations conferring Streptomycin resistance, other forms of Cu resistance and non-New Zealand forms of Psa) will continue to be restricted under existing protocols for both orchards and nurseries.