Maybe your friend should have cut the leaves off before sending the scions? Or were they exposed to frost in transit? I hope they will take, but if they don't, it might be more because of the quality of the scions, than your expertise as a grafter.
You are way too kind!
Hopefully i'll be a good grafter enough to have them to take, but honestly, i share your idea that the wood doesn't look good. I also think that he should have cut the leaves, but he was so quick and kind in sending me those, without asking anything in return, that didn't even dare tell him that they won't probably take.
Here are two pictures of my FrankenFeijoa's, I'm keeping my fingers crossed:
Your grafts looks good from here! However i tend to think along the lines of fyliu, and probably some bigger sized scion could have encountered more success? I have noticed on mangoes that if you graft some bigger scions, compared to smaller scions of same age, they tend to be more successful; i thing along those lines: probably bigger scions better retain their humidity giving the cut more time to heal.
So, i usually try to graft the biggest 1-year old wood that i have available.
Your Myagawa T-bud looks good, and interesting that you prefer tying with raffia, I have never tried that.
I like raffia because it isn't elastic at all, and you can do a really tight tie... you can do it with other materials, i have for instance a chip-budding tape, but it tends to deform if you put it under too much stress, and also it is sticky and becomes a nightmare to apply properly in certain situations (dusty/dirty environment when you t-buds very low on a freshly plowed field). I don't know how much of this holds true for electric tape, but the sticky part for sure remains. Parafilm is good when you want to keep the scion insulated from the external world, but isn't very efficient when you want to hold something in place... unless you use a lot of it. Of course para-film is one of my favored materials for grafting, but for t -bud raffia works really well, even more if you consider that a properly done T bud doesn't need much sealing, if at all, if your ties is strong enoug. So... rafia to me is just more convenient (also: biodegradable).
A good practice for grafting guava is to prepare the scion by stripping all the leaves, tipping and waiting about a week for it to swell before clipping.
At this point it's too late to attempt this, only precaution i had on my pineapple guava was the be sure it was was well hydrated: but i definitively will keep this in mind when i'm gonna try this again!
This information would help us have a better idea of factors affecting grafting success rates.
Timing, scion size, rootstock age, grafting method, location of graft on plant.
Oh, now that you make me think about it, i also tried a side veneer graft. Saw solko has success with it so i though "Why not?". I have even less hope on this one that on other grafts, it was my first side veneer. Well, more of a chip budding now that i think about it.