sigatoka disease is caused by a fungus, and is one of the most dangerous
diseases on banana. A farmer can lose up to 70% of their production. The
disease usually appears when the 3rd or 4th leaf forms. Yellow, brown and
black lines that follow the secondary leaf veins appear on the underside of
the leaf. This disease can be easily confused with other fungal diseases that
caused spots, but not brown or black lines. Chemicals can be used to control
this disease, but they are expensive, not always available, and can be
dangerous to human and agricultural health.
fungus lives mainly on the leaf when it is reproducing, and is more visible
during the humid rainy season. It can be transported from one leaf or plant
to the other by the wind, unclean agricultural tools or through contact
between two leaves. The fungus can also live on other plants (host plants)
when the banana tree is not present. Getting rid of infected plants, or other
host plants, is an cultural practice that can help reduce the amount of
disease that is already present in the field. If we get rid of infected
leaves and destroy them, it reduces the potential spread for next season.
However, it is a practice that needs to be done repeatedly.
Monitor your field once a
week from the planting of seeds or seedlings until the tree is mature, in
order to notice the symptoms early
If you see an infected leaf,
cut the leaf carefully, trying not to shake it too much, at its base. Put the
leaf in a large pastic bag to avoid spreading the disease to the rest of the
field. Take the bag outside the field, and deposit the contents onto a fire.
You can also bury them deeply if you wish. Make sure you fill the hole again
if you do.
If the whole tree is badly
infected, cut the tree down and bury or destroy it on the spot. Do it quickly
to avoid the spread to other trees in your area.
Do not forget to clean your
tools after working on this disease. Clean with ethanol or bleach, or put the
tool over the fire for 10 to 15 seconds.
The foliar symptoms are easily found on
the 3rd or 4th leaf during growth.Photo byScott Nelson
The symptoms are brown spots at the
beginning, with a black and yellow
halo. The centre of the spot dries up after a while.Photo byGerald Holmes, California Polytechnic State University at San Luis Obispo
The recommendations in this factsheet are relevant to:
Democratic Republic of the Congo