I was picking nuts from the young trees planted all around my house, when a came to a Kanza tree that just screamed at me to take its picture. Not for all the nuts it was producing but for the extremes in branch attachments I could see, all on the same tree. The lowest branch on the tree (above left) had the classic worst case scenario for a branch attachment--a deep crevasse on the upper side branch union. These kind of branch attachments are very prone to breakage and often lead to massive trunk tearing when the limb breaks out. Further up in the tree all the branches had picture-perfect, branch attachments displaying a textbook version of a strong branch collar (above right). The question is, how did these branches form and is there anything that can be done to encourage strong branch angles?
I noticed when training these young trees that fast growth rate promoted the development of stalked buds (buds on the ends of stem like projections) in the upper portion of the tree. By mid-summer these stalked buds were all starting to sprout and I had to remove all of these new shoots to maintain a strong central leader. Leaving a stalked bud to grow is a big mistake, because the branch that forms from this bud will produce a branch attachment like the bad one pictured above-left. By pruning off the stalked buds, I forced the tree the sprout from secondary buds the following spring. When these buds grow they tend to make great branch attachment unions. In the case of my Kanza tree, it looks like I missed a stalked bud early in the life of my tree. This problem branch will not be a problem much longer--I'll be removing this branch early next spring.