My Dragon Fruit Has A Large White Spot On It. Is That A Disease?

Question

The white spot is in several places. See picture. What do I need to do to make the plant green and healthy?

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Answer 1

This could be scale damage, spider mite damage, or overwatering damage. Regardless, it is either bacterial or fungal.

Treating with a fungicide, and keeping the soil on the drier side can help. These articles will help:

https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm