Fungus Control On A Crab Apple Tree?

Question

Nearly every leaf is discolored and curling up, what do I do to rid it?

Answer 1

It could be disease, a pest, or environmental problem. If it is a fungus, it is too late to apply a fungicide. Powdery mildew is common and causes a white powdery substance on the leaves and brown discoloration. Sanitation is the key in that case. Pick up and remove to the trash leaves as they fall.

These articles should help pinpoint the problem.

https://www.gardeningknowhow.com/edible/fruits/apples/apple-leaf-midge-control.htm

https://extension.psu.edu/crabapple-diseases

https://hort.ifas.ufl.edu/database/documents/pdf/tree_fact_sheets/malsppa.pdf

https://edis.ifas.ufl.edu/publication/FP394