|September 2006. Banana plants on several islands in the Maldives have been affected by a disease which, in severe cases, causes the stem to break. The disease affects the outer layers of the pseudostem. A strong odour is associated with the rotting.
Hunter DG (1996) identified this phenomenon as 'Banana wet rot complex', and mentions the fungi that are associated with it: Cylindrocarpon musae, Fusarium solani and Acremonium sp. The Maldives are atolls, and crops often suffer from nutrient deficiencies that may promote diseases.
There were several ideas as to the cause:
- Potassium deficiency (see leaf edges) - but whether it makes the plant more susceptible to the rot complex can only be speculated. The farmer could try adding Vigna marina, mangrove leaves or ash to provide some potassium.
- A bacterium such as Erwinia, rather than a fungus. However, a number of fungi have been recorded in association with these kinds of rots and it seems to be difficult to determine which is the primary cause. A general nutrient deficiency may contribute, but in at least two of the pictures the plants looked quite good nutritionally. There is probably little that can be done to prevent infection, other than rogueing and removing affected plants, and composting them away from the plantation, in order to reduce the amount of inoculum in the block.
- Bacterial rots such as those of Erwinia chrysanthemi.
- It was also mentioned that in Papua New Guinea similar rots are caused by Marasmiellus sp., but in these cases the symptoms are associated with wet conditions, and toadstools of the fungus can be seen growing on the stem.