What is the dusty looking mist on young plumeria leaves? It does not look like rust.

Question

Young plumeria branches have some sort of fungus?

Answer 1

It could be powdery mildew, which is a very common fungal disease.

Here are steps to prevent and control it:
https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm

https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm