why does plant form new roots during air layrringr layering

Hi friends
I did a lot of air layring(AL) with tropical plants with many do's and dont's . I tried all year in every season . Except caussaurina all
Tropical plants responded good in rainy seasons. But my cassurina showed new roots from july to march. But my bouguvilla did not show any results.i had been AL without the knowledge of the plant psycology to grow new roots.i AL as i wanted new roots or say new plant.
So my question is what is the purpose for the plant to grow new roots. As the new roots are tender so the using of moss i understad is as the moss has the capacity to hold water and is soft for the movement of young roots.
So the next point is the temp. And humidty level as the this condition will help the growing of new roots.
So coming to the question what is the plant mind to grow new roots . As there is no nutrition value in the moss. Or the plant is getting nuttrion from beneath old roots.
Or the new roots may be new cammbium which the plant is making to merge with the other trunk but the gap or the wire prevent it from merging. When the roots have grown we cut and plant and the new roots harden
Pls clarfy me....

This is an excellent explanation:

http://www.evergreengardenworks.com/airlayer.htm

Moved to questions

Hi
jim and andy
The information on the site is good
Thanks

amanluthra. I don't mean to highjack your thread but I have a question relating to this topic if you don't mind.

I layered (first AL) a Jap Maple (Katsura) 3months ago and opened it yesterday. No roots have formed yet but it looks like it is starting. Little white "bumps" (for lack of a better word) are forming. I'm just wondering how long it usually takes for this species to form roots. Anybody have any experience with this?

fredman1 wrote:I layered (first AL) a Jap Maple (Katsura) 3months ago and opened it yesterday. No roots have formed yet but it looks like it is starting. Little white "bumps" (for lack of a better word) are forming. I'm just wondering how long it usually takes for this species to form roots. Anybody have any experience with this?

It usually takes 10 to 12 weeks, but can be as short as 6, to have harvestable layers: layer is made May/Jun (Oct/Nov in NZ?), harvested and potted in Aug/Sep (Feb/Mar in NZ?) which, in my climate gives the explants about 6 weeks to grow on their own before leaf fall.

BTW, you should see lots of white roots, similar to this before you cut it off and plant it. You can always over winter it on the tree, whereas removing too soon can kill your new tree because it doesn't have enough roots to survive.

Hi fredman

Most of the AL takes place when the the weather is suitable for the plant to form roots
The suitable time is the suitable climate of the region. As i live in tropics the best time is the
Rainy seasonn in tropics. The temp. Is around 30 to 40 c and the humidity is above 60 percent . In tropics i have noticed that the seasonal time is good but the absence of humid factor in rainy season gives no roots.
Hence i think when there is correct readings in the nature then the the roots shoot in the moss.
Residents above or below tropics as i read the time for AL is the spring and
May be before autum. I personally do not have a practical experience. But the literature says. So look for your location.
And the white buds ?
I had a similar problem with the neem tree
Azadirachta indica showed same problem . The white thing is not the formation of roots
The plant may be wanting to join with the other part for its needs

WoW I can only wish I had that much roots. I only see little white stubs.
I layered it 12Sept when our Spring started. The tree has finished leafing by then but the weather was still pretty cold. There has been some viscous winds the first two months and not to much heat. It really only started warming up in the middle of Nov. If the white stubs aren't roots, then it must be the beginning of a callous. If that is the case do I remove them to get the root growing process started?
I am really very confident (and proud) with the AL procedure I did. The problem must be with the weather. I will leave it on as long as it takes.  I removed all growth (yesterday) beneath the girdle. Beneath the girdle is only the main trunk. After I did that some small voice said to me "That is not a good thing". Now I have a few voices in my head all saying different things..... 

There are 5 to 6 different methods of AL which method u used like bark removing. Wire method. Bridge etc. Try with a diferent method to A l
Web search peter chan air lyring pdf format
That is where i was hooked

fredman1 wrote:...some small voice said to me "That is not a good thing". Now I have a few voices in my head all saying different things..... 

Read that article at evergreen garden works (link above in Jim Lewis's response). Read some or all of the others too - excellent resource about how trees work and making bonsai.

AND, FOR PETE'S SAKE, BE PATIENT!

When you take a potential layer apart you are setting the process back (or stopping it altogether). What is going to happen will happen. Some layers take; others don't. Fiddling with it mid process does NOT help.

If at first you don't succeed (and all that).

The callousing is a precursor to root formation. Don't remove the callous unless it bridges the bark cut section after a year. I have done many layers and the most successful are in warmer weather and root formation is almost always strongest on the side exposed to sunshine. Strong root formation is required prior to separation but again experience is key. Strong root formation on a Maple is going to be very much less than strong root formation on a Wisteria etc.

amanluthra...I used the method of removing the bark, lining it with moss and covered it with plastic. I wrapped some tinfoil around it to protect from the sun.

Osoyoung... Thanks for that. I actually have read it, and many others before I did the layer. I'm very confident with my procedure. It obviously is to early, but like I said it has been 3months. Time don't count for a tree though. Its all about the climate and that was not in its favour. I'll just be patient and keep an eye on it.

Jim... I am EXTREMELY patient by nature (that's why I love bonsai). After 3months I thought it best to take a small peek and ask the question. Believe me I wont "fiddle" with it. Like I said I will leave it on as long as it takes...

Kev... Thanks for that. I was hoping the stubs is the beginning of root forming. Actually when I saw it, it kind of looked "natural" to me...

Thanks Everybody