The Internet's Finest Tropical Fruit Discussion Forum!"All discussion content within the forum reflects the views of the individual participants and does not necessarily represent the views held by the Tropical Fruit Forum as an organization."
Is that new growth or old leaves?
I got the same symptoms on my small trees, not just sugar apple. It was because I used too much surfactant when I sprayed fertilizer. Some trees can't stand too much surfactant.If you didn't spray anything, then this could be something else.
Apparently it has leaf miner trails. Leaf miners are only active for a couple of weeks; there is nothing to be done now.