For over two decades, the kiwifruit industry, in collaboration with relevant regional and district councils, has been controlling wild kiwifruit in areas near kiwifruit orchards.

The reason we do this work is to prevent pests and diseases from spreading from wild kiwifruit vines into kiwifruit orchards, while also protecting the environment and the kiwifruit industry’s reputation.

Surveillance and control of wild kiwifruit now costs the industry and our partners over $600,000 annually. For this reason, KVH, with support from Zespri Innovation, is proactively looking for ways to slow the spread of seed from kiwifruit orchards into the wild in New Zealand.

To start, we needed to know what animals were feeding on the kiwifruit in our orchards and potentially spreading the seed. We initiated a project in collaboration with Lincoln University to investigate this further. Dr. Jon Sullivan, a Senior Lecturer in the Department of Pest Management and Conservation at the university, brings a wealth of knowledge in ecological monitoring and surveillance of invasive and native species in New Zealand, and how the natural world is responding to the many accelerating environmental changes being driven by human activities.

Jon in collaboration with Agriculture Risk Management (Te Puke), documented what animals were visiting kiwifruit orchards to feed on kiwifruit and potentially aiding seed dispersal into the wild. Four kiwifruit orchards in Te Puke were set up with trail cameras, tracking tunnels and AudioMoth acoustic recorders, and both green and gold varieties were monitored from April to September 2024.

The study revealed that assorted birds, possums and deer were the main animals feeding on kiwifruit, and that more fruit was eaten by birds than mammals. Overall, 90% of feeding detections were by birds, and the most detected bird species feeding were silvereye, pukeko and blackbirds.

A spatial analysis of the wild kiwifruit data also showed a strong relationship between wild kiwifruit and the proximity to kiwifruit orchards. In Te Puke, over 99% of mapped infestations are within 500m of a kiwifruit orchard, indicating that most wild kiwifruit today are direct descendants of orchard plants instead of offspring of seeds from wild plants.

This study emphasises the importance of removing all fruit at harvest time and dropping and mulching any leftover fruit after harvest, by no later than 1 July. During the winter months food sources become scarce for wild animals, so by eliminating a highly palatable and desirable food source from kiwifruit orchards, less seed will flow into the wild and less wild kiwifruit will establish.

Thank you to Zespri Innovation, Lincoln University, Agriculture Risk Management and the growers involved in this study to help improve our understanding of wild kiwifruit in New Zealand.

Images below: a deer and possum feeding on fruit.