Leaves with dead edges or patches
Herbicide damage
Cause: Spray drift of contact herbicides such as paraquat onto the plant.
Solution: Avoid spray drift onto leaves. Affected plants should grow out of the symptoms.
Manganese toxicity (dead patches)
Cause: Excess manganese in the plant due to the presence of manganese nodules in the soil profile and water-logging.
Solution: Confirm the diagnosis with a leaf analysis. Improve soil drainage and soil structure. Avoid planting bananas in poorly drained soils.
Mites (dead edges)
Cause: Feeding of the banana spider mite Tetranychus lambi, or the two-spotted mite, Tetranychus urticae on the underside of leaves. Severe outbreaks are usually the result of poor insecticide management which has destroyed beneficial insects.
Solution: Treat with an appropriate miticide. Ensure adequate coverage to the underside of the leaves.
More info:
Better Bananas – Mite summary
Queensland Department of Primary Industries
Plant Health Australia
Salt toxicity (dead edges)
Cause: A build-up of salt in the plant from high soil or water salinity.
Solution: Confirm the diagnosis with tissue or water analysis. Water heavily to leach salt out of the root zone. Seek alternative sources of water. Avoid excessive applications of fertilisers containing chloride.
Water stress (dead patches)
