What's it look like?

You'll notice that your plants, especially tomatoes, wilt on hot days. Lower leaves on the plant turn yellow and suddenly the plant does not perform well. If you cut open a stem you'll notice brown streaks running up the stems.

What it attacks

Tomatoes, passionfruit, melons, cucumbers, pumpkins

What to do before it arrives

Dig in wood ash to the soil when planting. Wood ash contains potassium and can help reduce the incidence of the fungus.

What to do if you already have problems

Use garlic spray and apply it every couple of days. Be mindful that garlic spray will kill other beneficial insects.

Fusarium wilt is a soil borne fungus and can stay in the ground for years. It's essential that you practice crop rotation, so don't plant into the same area again with similar crops because you'll only make the problem worse.

For further information:

Fusarium Wilt of Lettuce - full slides
... Fusarium wilt of lettuce ... Yuma Agricultural Center. Fusarium wilt (root rot) ...
http://ag.arizona.edu/crop/presentations/2003/matheron120303.pdf

Fusarium and Verticillium Wilt of Tomato
Information on Fusarium and Verticillium Wilt of Tomato including scientific name, hosts, description, recommendations and references. ... Two major wilt diseases of tomatoes are Fusarium and Verticillium wilt. Fusarium wilt, the most prevalent of ... The affected leaves soon wilt and dry up, but they remain attached ...
http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/tomwilt.htm

Fusarium Wilt
Fusarium wilt is soilborne and nearly impossible to get rid of. Read about it and how to control it. ... Subscribe to My Topic. Fusarium wilt is actually a fungus called oxysporum ... Control the bad nematodes and you may not see a problem with the fusarium wilt ...
http://www.suite101.com/article.cfm/1882/52818

Fusarium wilt of melons (watermelon, rockmelon and honeydew)
Fusarium Wilt of melons was previously a highly destructive disease in Queensland. In recent seasons Fusarium Wilt has started to reemerge as a problem; symptom descriptions, and management advice are given. ... Australian watermelon production was severely limited by Fusarium Wilt. Growers were continually moving to ... to those of the classical Fusarium Wilt, and others showing symptoms of ...
http://www.dpi.qld.gov.au/horticulture/11645.html

Fusarium wilt in asparagus plants
... Fusarium wilt in asparagus plants ... Could be fusarium wilt. Find out what this fungi is and what to do about it. ...
http://www.allsands.com/Misc1/asparagusfusari_uxb_gn.htm

What is fusarium wilt?
Tomato plant leaves yellowing and wilting? Could be signs of fusarium ocysporum wilt, a soil-inhabiting fungus. Learn more. ... To confirm fusarium wilt in tomato plants, you can slice the stem of the plant lengthwise at the soil ...
http://ks.essortment.com/fusariumwilt_rcir.htm

Fusarium and Verticillium Wilts of Tomato, Potato, Pepper, and Eggplant, HYG-3122-96
Solanaceous crop plants (tomato, potato, pepper, and egg-plant) may be infected at any age by the fungi that cause Fusarium wilt and Verticilli ... collapse rapidly and die. Fusarium and Verticillium wilts are rarely significant in ...
http://ohioline.osu.edu/hyg-fact/3000/3122.html

Fusarium Wilt
Fusarium Wilt. Symptoms: When disease begins, wilting may occur but plants often recover their stature overnight. Stems and leaves of only one side of a plant may initially discolor or wilt. ... Root knot nematode injury can increase severity of Fusarium wilt. ...
http://cropdisease.cropsci.uiuc.edu/alfalfa/fusarium-wilt.html