Tuesday, June 24, 2014

Notes of this year's grafts

   Over the past couple of weeks, I have been trimming and training my successful grafts. The new growth I've seen on my grafts this year have been outstanding. The photo above is just one example of a tree I grafted with a Kanza scion placed on a 1.5 inch diameter seedling pecan tree using a bark graft. Before I shot this photo, I removed all rootstock suckers, pruned the graft to one shoot, removed stalked buds, then tied the new shoot to a bamboo stake. I protected the entire tree from deer with a 5 foot tall welded wire cage.

   In trimming this tree, I noticed a couple of things that I thought important to point out. The first has to do with the small piece of grafting tape I tied around the scion. I applied the grafting tape to seal in the moisture inside the plastic bag that surrounds the graft union. But look how thin the 1/2 inch tape has already been stretched by the rapidly growing scion. The original scionwood I placed on the tree was roughly the same diameter as the pruning cut you now see at base of this year's green growth.  In just 6 weeks time, the scion stick has  increased in diameter two fold. To prevent possible girdling by grafting tape, I removed the tape but left all other graft wraps in place (photo above).

   In previous posts, I have written about the tree training problems that can be caused by allowing stalked buds to develop on a tree's central leader. I have usually associated the appearance of stalked buds with the growth of young trees but I've never before have I seen stalked buds develop on a new graft--that is until this year.
    At right is a series of four photos that show the buds growing on the graft shown at the top of this post. The first photo (at right) shows the buds on the lowest portion of the scion's new shoot. Here the buds appear small and tightly appressed to the stem.

    Moving up the stem, I found that the lowest bud pictured in the photo at right was small and tight to the stem. However, as I looked up the stem the buds started to develop short stalks.


    Further up the new shoot, stalked buds were longer and looked like they might start sprouting leaves soon (photo at right). If I allowed these buds to remain on the tree, it wouldn't be long before the tree would develop a brushy top with no clear central leader and numerous narrow-angled branches.
   Could it be, that I've just discover the origin of the phrase, "nip it in the bud"? I had to nip off these stalked buds before they could create tree structural problems.
    Finally, I looked at the very top of the new shoot (photo at right). Here I found that stalked buds were developing at the base of leaves that were still expanding. Amazing!
  In training this new graft, I removed every stalked bud on the scion's new shoot, from top to bottom. In 2-3 weeks, I'll revisit this tree, pruning where needed and pinching out any new stalked buds that form.