I would play it safe and remove most or all the fruit, it is not worth losing a graft.

Just an update on this project. Despite having the growth from the grafts supported by bamboo canes that I've strapped to the stumps of the host scaffolds, I have been having lots of issues with grafts blowing out and breaking off during storms. I lost a half-dozen branches last year in the first season of growth, and have lost 4 so far this spring/summer. This has happened with both cleft and rind grafts. Although there is generally decent callus/growth supporting the new branches, there is not enough to stop the branches, which are getting fairly large, from breaking. This past week I lost a couple well branched grafts with about 3 1/2 - 4 feet of growth from last year, and another foot and a half from this year. Does anyone have suggestions on how to stops the blow-outs? I'v considered thinning and pruning back the growth, but that seems counter-productive since the goal is to get to a large, producing tree as soon as possible. I started off with 2 - 5 live grafts per scaffold, and with some thinning and the blow-outs, on a number of the scaffolds I am down to 1 or 2 surviving grafts. Is this a possible sign of imcompatibility between the rootstock (crabapple) and the topworked varieties (September Ruby and Norda), or just a mechanical issue that will be resolved with time and more growth of the union?

I had the same problem, I loose fewer grafts when I do W/T, but that is impossible on larger wood. Summer pruning would be an option, it might set the graft back a year, but at least it will be strong and still there.

Thanks ubro. I have been thinning out unwanted inward, crossing and downward branches all along but yesterday I removed about 1/3 of the laterals that were growing off the grafts. You get 7 or 8 new laterals on each graft, each a foot or eighteen inches long, with large leaves -- that catches a lot of wind. Hopefully with being more aggressive with the summer pruning and the passage of time, that will address this problem. I would like to leave at least a moderate crop next year (3rd year), but am concerned that the grafts won't be able to hold the weight. Incidentally, the second crapapple tree that I top-worked (not the one in the pictures above) was primarily grafted to Collett and I have had minimal problems with blow-outs so far. The grafts on that tree are far less vigorous, with growth on most just reaching 3 feet now, well into the second year of growth. The lesser vigor I think is because this tree gets a lot less direct sun. So it will be interesting to see if I start to have the same issue once the grafts grow beyond 5 feet.