Pest watch: Wilt (November 2025)
18 November 2025
18 November 2025
Fusarium wilt: a hidden threat to healthy production
Unlike water- or insect-borne diseases, fungal infections can be harder to detect. Some species grow quietly as endophytes within non-susceptible plants or persist for long periods on dead and decaying organic matter. These unseen pathogens can quickly become a serious problem once conditions are right.
Fusarium oxysporum is a fungal species complex, that adapts to a wide range of crops. At least a dozen species are recognised in Australia. Each tends to ‘specialise’, infecting some species and not others. This means some infected plants can act as symptomless carriers while others rapidly wilt and die once the pathogen takes hold.
A killer in disguise
Symptoms caused by Fusarium can look similar to those caused by other wilt and crown-rot pathogens such as Phytophthora, Pythium, Calonectria.
Common signs include:
- yellowing or wilting leaves
- discolouration of water-conducting tissues in stems or roots
- stunted growth
- premature ripening or plant death.
Infection is incurable, wilt and death inevitable
Once infection occurs, there is no cure—prevention is the only protection.
Plants at risk and preventative measures
In nurseries setting, susceptible hosts include (but aren’t limited to):
- carnation
- beans
- cyclamen
- ginger
- gladioli
- dipladenia
- cucurbits
- tomato
- hebe.
Fusarium oxysporum spreads through contaminated soil, water, plant material and clothing—essentially any surface or tool that can carry spores.
To reduce risk of infection:
- Monitor all incoming stock, particularly species known to be prone to Fusarium wilt
- Only propagate from healthy mother stock plants. If any part of a plant shows wilt, do not take cuttings from it
- Stay informed. Note which varieties are resistant or susceptible or resistant and plan accordingly.
- Maintain hygiene. Clean and disinfect benches and growing areas and tools, and remove plant debris promptly.
- Use clean water sources for irrigation. Mains water or disinfected water is best.
- Provide optimal growing conditions. Saturated media and high nitrogen fertilisers encourage disease development.
Suspected infection?
Send suspect plants to a diagnostic laboratory for identification.
All production nurseries receive 6 free samples at Grow Help Australia. For more information on the biology and management refer to the Fusarium factsheet, or the Pest ID tool.
