What is the yellow rust powder on my frangipani leaves

Hi Jack,

The yellow/orange powder under your frangipani leaves is called 'rust'. This rust can be controlled by spraying the tree with either a product called Yates Rose Shield. One of the active ingredients in both these products is called Myclobutanil. It is a systemic fungicide that is absorbed into the plant's system and translocates around the plant to control these fungal problems. Spray every 2 weeks until you can get this rust problem under control.