The fungal pathogen Fusarium oxysporum affects a wide variety of hosts of any age.
[2] F. oxysporum generally produces symptoms such as wilting, chlorosis, necrosis, premature leaf drop, browning of the vascular system, stunting and damping-off.
Each forma specialis within the species are host-specific (i.e. specific to a certain plant) and produce different symptoms: F. oxysporum f. sp.
[10] F. oxysporum has no known sexual stage, but produces three types of asexual spores: microconidia, macroconidia, and chlamydospores.
They are round thick walled spores produced within or terminally on an older mycelium or in macroconidia.
F. oxysporum is a common soil pathogen and saprophyte that feeds on dead and decaying organic matter.
Eventually the spores and the mycelia clog the vascular vessels, which prevents the plant from up-taking and translocating nutrients.
As previously stated F. oxysporum is a common soil saprophyte that infects a wide host range of plant species around the world.
[1] Though Fusarium oxysporum may be found in many places and environments, development of the disease is favored by high temperatures and warm moist soils.
It is a soil-borne pathogen, which can live in the soil for long periods of time, so rotational cropping is not a useful control method.
It can also spread through infected dead plant material, so cleaning up at the end of the season is important.
Other control methods include planting resistant varieties, removing infected plant tissue to prevent overwintering of the disease, using soil and systemic fungicides to eradicate the disease from the soil, flood fallowing, and using clean seeds each year.
It is difficult to find a biological control method because research in a greenhouse can have different effects than testing in the field.
The best control method found for F. oxysporum is planting resistant varieties, although not all have been bred for every forma specialis.
It can be controlled by breeding for resistance and through eradication and quarantine of the pathogen by improving soil conditions and using clean plant material.
[12] The fungus Trichoderma viride is a biocontrol agent that has proven to control this disease in an environmentally friendly manner.
F. oxysporum also causes damage to many crops from the family Solanaceae, including potato, tomato, and pepper.
Other commercially important plants affected include basil, beans, carnation, chrysanthemum, peas, and watermelon.
In South Korea, where Fusarium wilt is the most serious soil-borne disease of strawberry, losses in transplant production of up to 30% have been reported.
Certain pathogenic strains of F. oxysporum could be released to infect and control invasive weed species.
This type of control (called a mycoherbicide) would be more targeted than herbicide applications, without the associated problems of chemical use.
Bananas are a staple food in the diet of millions throughout the subtropics and tropics, and the spread of Panama disease could have devastating effects on both large scale production and subsistence farms.
cubense which may have originated in Asia and just recently has appeared in banana producing areas in the South Pacific.
Importantly, plants used for cuttings carrying no outward symptoms of infection may still transmit the pathogen.