Allocasuarina Torolusa Airlayer Failure?

[BlamJams]

It's been about 8 weeks and both top and bottom are looking ok, but there is not sign of rooting in the airlayer.
The vertical scar is from when I cut away the bark and cambium. At the time of the airlayer I'm certain it was back to bare wood.
I did a few others on other plants - olive, ficus and tilia. So far only the ficus is showing (many) roots.

Have I not waited long enough?
Can anyone read into the picture at all?

Thanks.

Airlayer.jpg

[Bougy Fan]

It has bridged the layer - that is the bit joining both on a a bit of a spiral. The tree will always try to bridge rather than have to put pout roots. Recut it and did you use a rooting hormone ?

[BlamJams]

Thanks Tony,
I'll do that tomorrow.
Yes, I used a hardwood root liquid. Yates Clonex, Red.

Should I expose fresh cambium on the upper portion?

[KIRKY]

Difficult to tell, but you have to scrape back all the cambium to stop the bridging. Recut scrape right back more hormones and try again. You could also put a tight ring of wire ( a tourniquet) to also stop bridging.
Cheers
Kirky

[Ryceman3]

100% bridged as suggested by Bougy... re-scrape the area, you can re-cut the top if you wish but just cleaning it up and re-applying the root hormone to the top edge should be enough...
EDIT: Kirky beat me to it... but just to emphasise!