Remedy for Malaysian Mum Flowers With Early Blight?

How do I cure Malaysian mum flower attacked by early blights. I don't know how to get rid of this kind of flower disease, as this is my very first time to do gardening.

My plants were in a greenhouse and was planted 2 months ago. I tried to use fungicide, but it does not make sense, the leaves were severely spotted with yellow color until the leaves become dry. Thank you in advance!

By jmpier