A study in the UK has found 10 species of Phytophthora in one puddle of water!
The Forest Research findings highlight that water management is an important element of disease management for all nurseries. The group undertook a survey of nurseries across the UK and found almost 50 Phytophthora species, and at least one species was present in 50% of samples.
It is well known that water is often linked to Phytophthora and that good drainage is a key management tool. This was confirmed in the study, which also found where river water was used for irrigation Phytophthora loads could be high and open water sources such as tanks or reservoirs could be prone to contamination and should be covered where possible.
The study also found that shelter belt trees could be infected with Phytophthora and add to the inoculum load, which is one reason why we have included shelter plants in our proposed Pathway Management Plan for the kiwifruit industry.
Phytophthora is present around the world, including New Zealand, in a wide range of hosts. There are many reports of different Phytophthora damaging kiwifruit vines in different regions globally and it is considered highly likely that under certain conditions (i.e., wet soils) kiwifruit would be susceptible to several Phytophthora species. Read more, and see images, on the KVH website.
KVH has incorporated Phytophthora measures into our Kiwifruit Plant Certification Scheme (KPCS) to reduce the likelihood of Phytophthora being spread on kiwifruit nursery plants, and we have also supported the development of the Plant Pass certification scheme which looks to reduce the likelihood of high-risk organisms (including Phytophthora) being spread on all species of nursery plants.
KVH is also interested in hearing from growers who would like to be included in the industry survey of Phytophthora pathogens in kiwifruit orchards. This spring a further 25 sites from the Northland, South Island and Bay of Plenty regions are planned to be sampled as part of this two-year project. Read more here.