All I had to graft from was this little tip piece. It has been in a plastic bag for 8 days with little change. The two buds close to the stump seem viable, should I remove the tip?
For me apples can take up to about a month before first growth- usually takes a couple weeks. I once had a graft that didn’t grow until the second season, but that was a “miracle”. You pulled the bag of for the photo, right?
I won’t cut off the tip. Don’t see what that will help.
Don’t cut it, no reason to. Also I would not bag it unless it is always fairly cool, if it gets into the high 80’s/90’s your graft is going to roast.
I always thought it took about 2 weeks to callous under good conditions.
I stopped grafting apples a week before last weekend’s heatwave. Some of the those last grafts sprouted on third day of the heatwave. I’m a little concerned stored energy within the scionwood will get used up before the graft is healed enough to support the new wood.
It seems like there is always some reason to worry. 
It looks OK in this photo. Keep us posted. depending on how deeply dormant a scion is, affects it’s wake-up time. Also, I don’t like to use scions so close to the end. older wood is more robust.
Older wood probably has higher carbohydrate reserves. But that tip section isn’t going to run out of reserves before growing.
Apple leaf buds require both high chilling and then considerable heat units before growing. The chilling should be taken care of before wood was cut or in the fridge. But the heat units after that could be at various stages of fullfillment at grafting. It will grow when all that is in order. No hurry is there.
FN is right, you take the wood out of the fridge after the tree has been exposed to warm temperatures for probably a couple of weeks. Even if the tree is barely showing signs of growth it is ahead of the scion. I think that is part of the strategy in getting grafts to take before dehydrating, although I’ve had good success grafting wood the day I removed it when trees are first pushing bud.
Yes
The apples on the nurse branch are the size of a dime. Everything else that was grafted to the stump has 1" or more growth, the reason for my concern. I would of loved to use stouter scion but was all I got from the supplier. The scion wood was in the frig for 3 months.