New Zealand Plant Protection 66 (2013): 242-248
Phytophthora taxon Agathis (PTA) is a serious problem in Auckland and Northland kauri forests. Phosphorous acid (phosphite) is a potential treatment for infected or threatened trees. In vitro tests on phosphite-amended agar showed that PTA was more sensitive to phosphite than other Phytophthora species commonly controlled by this chemical. Before progressing to forest trials, phosphite efficacy was tested on PTA-inoculated kauri seedlings in the glasshouse. Two-year-old kauri seedlings were inoculated with PTA applied directly to trunk wounds or by soil application. Phosphite was applied as a foliar spray, as a trunk injection or as a soil drench either 5 days before or 5 days after inoculation. All untreated control trees died, whether trunk- or soil-inoculated. With phosphite injection, survival was 100% following PTA soil inoculation and 67% following trunk inoculation. Foliar spray and soil drench-applied phosphite treatments were less effective than trunk injection, although some trees survived.
Keywords: phosphite, kauri, Phytophthora taxon Agathis.
 | Forest efficacy trials on phosphite for control of kauri dieback I.J. Horner, E.G. Hough and M.B. Horner (2015) New Zealand Plant Protection 68: 7-12 |
|---|---|
| Surveillance methods to determine tree health, distribution of kauri dieback disease and associated pathogens N.W. Waipara, S. Hill, L.M.W. Hill, E.G. Hough and I.J. Horner (2013) New Zealand Plant Protection 66: 235-241 |
Copyright © 2013 New Zealand Plant Protection Society (Inc.).
Please refer to the terms of use.