Potential for beneficial root fungi to protect against kauri dieback

Abstract

A new project was initiated in 2012 with the Te Whangai Trust native plant nursery. Ten treatments of root endophytic Trichoderma isolates from very healthy local plants were applied to ten New Zealand native plant species including kauri. All treatments improved germination, growth and health compared with untreated controls. One treatment was outstanding. The project is continuing and has led to a separate post-doctoral project on the potential for selected Trichoderma isolates to control kauri dieback disease (Phytophthora taxon agathis, PTA). Kauri will be treated with three of the best Trichoderma mixtures identified in the previous native plant project. Seedlings will then be challenged with PTA and monitored. Root samples will also be taken from healthy kauri trees and other local plant species to obtain additional Trichoderma isolates that may provide protection from PTA. The best Trichoderma treatment(s) will be applied to kauri and trialled on PTA-infected sites. We expect to observe an increase in resistance to PTA in kauri inoculated with the best Trichoderma treatment. This may provide a natural control option for PTA in kauri. The project will involve close collaboration between the, Bio-Protection Research Centre and Te Matapuna Kaupapa Māori Unit, the Māori community (including Tangata Whenua Roopu), the Auckland Council, Te Whangai Trust and Winstone Aggregates.