Tonytran, the execution of the air layering is perfect. But from my point of serious sight better instead of making an air layering, to graft on the most appropriate rootstock (depending on terrain), if it is a land with very moist soils, it is best to use Diospyros virginiana, and for the driest land Diospyros Lotus is better . In your case with air layering, what you get will be a variety with a rootstock Diospyros kaki ( and no one knows how it will behave in different types of terrain) , although usually performs well. There is a boy from San Diego, who has problems with his kakis grafted in Diospyros Lotus (usually this rootstock has problems in humid lands, as this rootstock has a very shallow root system, only deepens in the land , about 40-50 centimeters ) while the Diospyros virginiana has a very deep root system (this rootstock is more resistant to soil moisture and provide to the grafted variety increased resistance to fungal diseases), next February , I will send some seeds of this rootstock. The difference between the two rootstock is like night and day. It seems that the rootstock Diospyros virginiana, is not widely used in the United States is this true? Best regards Jose

Shoaib - I think as a simple answer to your question - nurseries often opt for specific techniques to increase production of saleable product from limited quantities of scion stock, which also gives the benefit of being able to choose to use a variety of seedling rootstocks that are targeted to work well in different planting sites/conditions. So you can create many new trees to sell by grafting the buds from a single larger branch onto many rootstocks versus air-layering a single branch to create only one new tree. I.e., a typical sized 12" - 18" cutting might have 6 - 8 good buds (more or less) on it to "make" 6 - 8 new trees vs only getting 1 tree from the same-size rooted branch that was air-layered. Even if you air-layer multiple branches from a large tree to make several new trees, you are reducing your future stock from that tree many-fold due to eventual removal of those branches.

There's a lot of good info on air layering on the web with pics too. I've not heard of anyone doing air layers with sugar apples since they fruit rather quickly from seed. So not sure how well they do during the process and after. If I did do an air layer from that plant, I would take as large a branch as he would let me. Otherwise, I'd just order a grafted one. Go to Ong's Nursery in San Diego. I'm sure he has some. Has this guy even seen blooms on his tree? Would he recognize them as blooms if it did? Do a search on hand pollinating cherimoya and that will give you the best approach at pollinating sugar apples.

There's other kind of layering, for specific plant, or for specific purpose. For papaya, half cut the trunk will work. For big branch fruit plants or bonsai that need big interesting root, big root grafted to branch then air layered is doable.