Hello, I've had a young soursop tree for about 4 months now over the past month or so I've noticed the leaves started looking rather sad. They are brown and white with holes in them I will include several pictures. The good news is from the bottom of the tree there is now some beautiful new foliage which I am extremely pleased with but I'm still wondering what the issue was with the original leaves on top. If anybody knows what this is I would greatly appreciate any diagnoses or tips you may have!

I don't grow Soursop trees but my first impression is that the tree isn't getting enough moisture to keep the top alive. Is your tree only getting water from your lawn sprinkler system? If so, it needs supplemental water.