Update - Liberibacter, 07 November 2008
Science Programme
Our science programme, which focussed on the distribution of the bacterium in commercial crops and answered some key questions on how this was being transmitted, has been completed and findings have been summarised as below.
Results show the bacterium is not transmitted in seed. We germinated seeds from infected tomato, capsicum and tamarillo and found no evidence of the bacterium in the seedlings at various stages of growth. We have confirmed that the bacterium can be transmitted by grafting. Results from both of these experiments are consistent with previous research that has been carried out on other known Liberibacter species.
Research carried out also confirmed that the Tomato Potato Psyllid (TPP), Bactericera cockerelli, can transmit the bacterium from the infected green parts of plants into healthy plants. This confirms findings from recent studies conducted by researchers in the USA.
Our study on the expression of the symptoms was inconclusive as we found that the bacterium could also be present in asymptomatic plants.
During the survey of commercial production sites, we tested a number of suspect host plants and found the bacterium in tomato, capsicum, tamarillo, potato, cape gooseberry and chilli.
Exports
Biosecurity Australia (BA) is currently undertaking a non-regulated Pest Risk Analysis (PRA). MAF Biosecurity New Zealand (MAFBNZ) understands that the formal consultation on this analysis may not be required. If this is the case, the time for completion of the analysis would be kept to a minimum.
The full reports from our science programme have been sent to BA. Horticulture New Zealand and associates have completed the Industry’s Code of Practice for managing TPP, as the vector of the bacterium, and this document has been passed to BA. Current indications are that BA is making good progress towards completion of the analysis and we have requested to see the final draft PRA and asked for confirmation of the completion date.
MAFBNZ staff will be meeting BA officials during the week of 17th November for bilateral discussions - one of the topics for discussion will be Ca. Liberibacter. MAFBNZ will then meet with industry and its representatives following this meeting to update them on progress with recommencing trade in solanaceous export products with Australia.
We are continuing our correspondence with Niue, French Polynesia and Fiji to negotiate amendments to their importing conditions so that those conditions, while still managing phytosanitary risk posed by the bacterium, do not unjustifiably disadvantage New Zealand’s growers and exporters to these markets.
Response Options
Now that the surveillance and science programme have been completed, MAFBNZ and industry will work together to determine the most appropriate course of action for the long term management of the bacterium and its vector.
Page last updated: 1 December 2008