Compost trial using reject kiwifruit

KVH has been working with the Bay of Plenty Regional Council to reduce the amount of wild kiwifruit establishing in the Bay of Plenty’s gullies, bush margins and production forests.

Wild kiwifruit is an environmentally damaging vine and may harbour Psa-V or other pests, which can then spread to nearby orchards. Reject fruit fed to livestock may be a potential seed-source of further wild vines, establishing when birds such as waxeyes feed on the softening fruit and distribute the seed.

A trial was undertaken by Kawerau-based Plateau Bark to see if compost could be made using reject fruit (and associated debris) mixed with pulp waste from the Norske Skog Tasman Ltd pulp and paper mill. The composted material was regularly turned and monitored. The trial was overseen by Plant and Food Research.

Temperatures within the compost piles were logged and found to be regularly above 60 degrees Celcius. Testing confirmed the end product was Psa-V ‘not-detected’ and kiwifruit seed had been destroyed during the high-temperature composting process.

KVH is now advancing the process to name Plateau Bark as a KVH-approved compost manufacturer using reject kiwifruit. Ongoing approval will depend on the compost product being consistently manufactured to prescribed standards, regularly monitored and free of Psa-V, other harmful pathogens and viable kiwifruit seed.

The relevant KVH Protocols will be amended to allow KVH-approved compost manufacturers to spread compost containing reject fruit, made to prescribed standards, onto Psa-V positive orchards in Recovery Regions.

For more information on this project, contact John Mather or Karyn Lowry at KVH on 0800 665 825.