Project reference: 2007-03
Management of Phytophthora in radiata pine seedlings
Objective: Short term
1. More effective management strategies for Phytophthora in forest nurseries
2. Potential to reduce the incidence of other fungal diseases and provide healthier seedlings for outplanting.
3. Leverage of FRST–funding (LINX0304 “Ecosystem Bio–Protection” and C04X0302 “Biosecurity, protection and risk management of New Zealand’s forests”) equating to $114,000 in 2006–07. Note – FRST will fund material costs and time commitment of T Reglinski and M Dick. NZFHRC will fund additional technical assistance required for the controlled environment evaluation.
1. Adapt management methods for non–radiata species e.g Douglas fir.
2. Methods may be developed for use in high risk plantation sites.
3. Potential methods for dealing with incursion.
Background: A serious outbreak of Phytophthora resulted in 30% mortality among P. radiata seedlings in block 4 of Te Ngae Nursery during 2005–06. A trial is being conducted at this site to investigate chemical and biological management options to mitigate the risk of Phytophthora. This is funded, in part, by FRST programmes LINX0304 “Ecosystem Bio–Protection” and C04X0302 “Biosecurity, protection and risk management of New Zealand’s forests’ and also involves significant in–kind contribution from the nursery.
Project Outline – NZFHRC Funding complements the Te Ngae nursery trial by optimising Phytophthora management methods under controlled environmental conditions. The selection of chemical and biological treatments for the Te Ngae trial has been based upon reported activity against Phytophthora, and also on our own observations of efficacy against Diplodia die back in radiata seedlings as demonstrated in FRST programme LINX0304. Because of prior commitments, there are insufficient funds in the FRST programmes to validate activity against Phytophthora before commencing the nursery trial. The NZFHRC project will dovetail with the FRST nursery trial by comparing a range of Phytophthora control measures under disease conducive conditions. The most effective treatments will be implemented in the nursery during March–May 2007 to provide protection for seedlings during the period when undercutting may expose wounded roots to Phytophthora infection.
In the NZFHRC study, various treatment combinations and rates will be applied as a foliar spray and/or as a root drench before and/or after trimming the roots of 4–month–old seedlings. The treated seedlings will then be planted into various media containing Phytophthora cinnamomi inoculum and monitored for disease development.