Fusarium wilt (yellows)

Cause

The fungus Fusarium oxysporum.

Symptoms

Leaves on infected plants turn yellow and fall. The plant wilts over several days and then dies. A characteristic symptom of fusarium wilt is the reddish-brown discolouration of the water conducting tissue of the stem and roots, seen when these parts are cut with a sharp knife.

How it spreads

The fungus can spread in contaminated soil, in infected seed and can spread as air-borne spores. Once introduced, the pathogen can survive in the soil for decades, even in the absence of susceptible crops.

The fungus infects through the roots, particularly where damage has occurred from cultivation or root-knot nematodes.

Occurs in both field and hydroponic production systems.

Crops affected

Basil, brassicas, curcubits, lettuce, alliums, pea, potato, snake bean, ginger and tomato.

Control

Avoid introducing the pathogen into production areas on contaminated seed, implements, footwear or in contaminated water.

Use resistant varieties or rootstocks where available.

Chemical registrations and permits

Check the Australian Pesticides and Veterinary Medicines Authority database for chemicals registered or approved under permit to treat this pest on the target crop in your location. Always read the label and observe withholding periods.