Project: 2002-04. Report - Fusarium circinatum – an agent of damping–off disease
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Date: 2003 Author: M A Dick & J Simpson Publication: Report Project reference: 2002-04 Full report is available from: |
Executive summary:
Background
- The susceptibility of six plantation and two pasture species of plants, to damping–off caused by Fusarium circinatum and to Fusarium oxysporum, was compared.
- Fusarium circinatum is the agent of pine pitch canker disease and can cause damping–off of seedlings in addition to causing canker and dieback of older plants. Fusarium oxysporum is a common inhabitant of nursery soils in New Zealand, causing damping–off and root rot to a number of species when soil moisture is high and conditions are conducive to disease.
Methods
- The plantation species tested were Pinus radiata, P. pinaster, Eucalyptus fastigata, E. nitens, Pseudotsuga menziesii and Cupressus macrocarpa. Lolium perenne (perennial ryegrass) and Trifolium repens (white clover) are representative of pasture species used when nursery beds are put into fallow.
- Pinus radiata and P. pinaster were extremely susceptible to damping–off caused by F. circinatum. None of the P. radiata survived and only seven percent (of seed sown) of the P. pinaster were alive at the close of the experiment. Lower levels of mortality were caused by F. oxysporum.
- Pre–emergence and post–emergence deaths of C. macrocarpa occurred in both the Fusarium treatments but were higher in the F. oxysporum treatments than the F. circinatum treatments. As damping–off associated with F. oxysporum is relatively uncommon in nurseries when conditions can be considered as ‘normal’ it is likely that F. circinatum would only be a problem to C. macrocarpa under extreme conditions. These are only rarely encountered in bare–root nurseries.
- Eucalyptus regnans was also far more susceptible to F. oxysporum than to F. circinatum. Total mortality in the F. circinatum treatments (61%) was only slightly higher than in the control and E. nigrum treatments (both 50%).
- Trifolium repens (white clover) was very susceptible to the isolate of F. oxysporum used in the trial but was unaffected by F. circinatum.
- Eucalyptus globulus and L. perenne were not susceptible to damping–off by either F. circinatum or F. oxysporum.
- No conclusions could be drawn about the susceptibility of Ps. menziesii due to very poor emergence in all treatments.
- It is possible that if a wider range of species were to be tested some conifers other than pines may demonstrate a level of susceptibility to F. circinatum.
Full report is available from:
Forest Research
Private bag 3020
Rotorua
New Zealand
