I would wait until the fall to transplant into the ground. The sunlight and higher temps will be less brutal on the small seedlings.

Definitely wait until they are about a foot tall before you consider transplanting. Look at the forum link below where I (enduser) give Roger advice on how to grow Sugar Apples. Same advice works with Cherimoya.

Here is a link that might be useful: How to care for seedlings

The pots are larger than needed. I would leave them in the pot for now. Wait until next year to see which one is the tallest and most healthy then pick those to plant in the ground. Also wait for more root to develop before planting out.

i sprouted alot of anona seedlings before but i never grew a single one to maturity.

im not that good at nursing seedlings.

I agree with Cherri regarding the pot size. I started some ina community pots and put them into the 8 packs that veggies and annuals come in. I then move them up to a four inch pot. My grafted trees that are about 2 to 2.5ft tall are in pots smaller than what your seedlings are in. I would consider putting them into the ground this year. My trees are growing very fast. Not like the grafted trees but I think once yours get to where they start branching, the growth is VERY fast. The only tree that grows at about the same rate for me is my 'Day' avocado. I remember Ajay in california telling me that they grow really fast. I was told that they can grow 5ft to 7ft a year.
Andrew

Thanks guys! I guess I will keep them where they are for the moment, and assess them again in a few months. Its good to know I don't need to transplant into larger pots. I chose this size after having papayas apparently stunted from smaller containers last year--but of course they are totally different plants.

That guide about sugar apples is useful enduser--even moreso because I also have (so far in germination) one small sugar apple seedling that I really hope will make it out into the ground.