Have we learnt the lessons from Psa?

Hort Talk
with Mike Chapman
HorticultureNZ CEO


Ten years ago, the kiwifruit industry found out that it had a bacterium called Psa-V that rapidly killed kiwifruit vines. But for the collective efforts of the industry, Government and Plant & Food Research, this crisis could have been the end of the kiwifruit industry. 

There were a number of lessons to be learnt but as with all learning, the question remains: Have we really learnt these lessons?

The first lesson was how important it is to control what crosses our borders and into New Zealand, to protect the primary sector and, as we know with Covid-19, people as well. The only effective control is to close the border, but as a trading nation that is not practical. So, what we need to do is make our border as tight as possible. Achieving that has fallen to a partnership between government and industry, where decisions and costs are shared should there be an incursion, but the responsibility for the border remains with the Government. This partnership is the ambulance at the bottom of the cliff. 

Queensland fruit fly is an example of a pest that gets into NZ every few years. And, each time we have had an incursion, government and industry have worked to eradicate it. The animal sector has been battling Mycoplasma bovis at some enormous cost, and it would seem from the reports that M. bovis will be eradicated. That is the gold standard. Most pests and pathogens cannot be eradicated, once here. They stay, and growers and farmers have to learn to live with them and somehow control them. Psa is one of those pathogens. It is here to stay and costs thousands of dollars per hectare to control so that we can have a successful kiwifruit industry.

Increase protections

We, therefore, need to be constantly working to increase protections, at our border and pre-border. This protection is an endless task to which we can never apply too much effort.  It is also a very expensive task but not as expensive as having to fight a pest or pathogen that arrives in NZ and settles.

Be prepared

The second Psa lesson was, be prepared for any likely incursion. Being prepared is difficult when there are so many possible pests and pathogens knocking at NZ’s border. What is being done is preparation for the most likely and devastating pests and pathogens. In the case of Psa, this was not the case. The concern remains, are we doing enough to be prepared for the next major incursion? This is where the Government and industry partnership becomes very important.


The third lesson goes to research into how to control pests and pathogens, and the breeding of new disease resistant plant varieties. The kiwifruit industry had and still has one of the world’s best kiwifruit breeding programmes. Out of that programme – and just in time – came some new gold varieties that were more resistant to Psa. But we always need to research new control methods, be they biopesticides or biological control agents. This research requires considerable funding and direction from the Government, supporting the industry.


Whole community

The fourth lesson was looking after the growing community – the whole community – so that it was able to manage and come out of the crisis. This is as important – if not more important – than the first three lessons. In NZ, we have an excellent network called the Rural Support Trust, which – supplemented by industry resources – can provide the welfare and mental health support the growing community critically needs. 

In times of crisis, people step up and lead, and the Psa crisis was no exception. Across the industry, people took on leadership roles that saw the industry recover. The programmes that were put in place held the industry together and, along with new plant varieties and management techniques, have enabled the industry to recover and come back stronger than before.

Through marvellous leadership, good planning and hard work, the kiwifruit industry survived. There will be more threats in the future, and today other sectors are facing incursions and learning how to manage and deal with invading pests and pathogens. 

What we must not forget are the Psa lessons. We must not cut back on preparation and funding. Covid-19 is teaching us that the world is a very uncertain place when it comes to human disease. It is no different with animals and plants. Constant vigilance is required.


There are no comments on this blog.

Leave a Comment

You must be logged in to make a comment. Login Now
Opinion Poll

We're not running a poll right now. Check back soon!