A biosecurity incursion: the impact of Pseudomonas syringae pv. actinidiae (Psa) on the New Zealand kiwifruit industry

Prior to November 2010, the New Zealand kiwifruit industry had a high economic growth rate. Kiwifruit was the largest horticultural export from New Zealand, with sales of approximately NZ$ 1 billion per year, and an 8.2% annual growth rate; and this industry was setting its sights even higher. With the incursion of Pseudomonas syringae pv. actinidiae (Psa), this impressive growth rate slowed. Psa is the causal agent of bacterial canker of kiwifruit. First recorded in Japan in 1984, the bacterial disease has had a serious economic impact on kiwifruit production. The virulent form of Psa, known as Psa-V, has severely affected kiwifruit orchards in Europe, New Zealand, Chile and China. The arrival and formal identification of Psa in New Zealand in late 2010 has transformed how kiwifruit will be grown in this country. The economic impact from the pathogen over the next ten years has been estimated to cost up to $ 1 billion. Adaption of the New Zealand kiwifruit sector to the disease is underway as the industry uses a fundamental understanding of the pathogen, the kiwifruit host and the environment, in conjunction with management, to map a pathway forward. An important aspect of the New Zealand research programme has been its linkages with a wide range of research providers both locally and offshore. Collaboration between organisations, industries and research agencies, both nationally and internationally, has been critical to the progress made so far. Lessons have been learnt with this incursion, and these will be shared as part of this paper.