If you are going to make perches, you have to make sure they are made from keet safe tree branches. And be sure the trees in your area are not treated with pesticides. Trees by roadsides are not good because of pollution.
Here's a list of non toxic(safe) and toxic- trees, plants and veggies http://www.parrot-and-conure-world.com/non-toxic-for-birds.html
You don't have to use only apple tree branches, any from the safe trees are fine.