Roots discoloured internally
Burrowing nematode, other nematodes
Cause: Burrowing nematode Radopholus similis feeding on the cells in the root cortex. Many species of nematodes in the soil also parasitise the roots of bananas.
Solution: Nematodes other than burrowing nematode are not usually a problem in the tropics. Check a random sample of roots over the whole field to determine the extent of the problem and if a nematicide treatment is necessary.