Anticipate Dominance with Multiple Varieties Grafted On The Same Root Stock
The idea of one tree with various varieties of fruit is an interesting idea to some backyard fruit growers who have limited space. However, the grower should be aware that frequently, one variety will be dominant over another variety as the tree grows, and the tree may require frequent and judicious pruning in order to maintain the tree in good balance and appearance.
During the summer of 1993, we set out new trees to replace some that had been destroyed during Hurricane Andrew. Included among those new "set outs" was a Valencia Pride mango and a Tommy Atkins mango, both of which were between 49 to 60 inches high at the time. In the Fall of that year, we took a scion from the Tommy Atkins tree and grafted it onto the Valencia Pride tree. We also took a scion from the Valencia Pride and grafted it onto the Tommy Atkins tree. In other words, these two trees were "cross-grafted" onto each other.
The aggressive Valencia Pride graft outgrew the original Atkins tree and threatens to dominate the whole tree. We maintain things in balance with frequent pruning on the Valencia Pride side of the tree.
In the photo, the original Valencia Pride tree can be seen on the left. The less aggressive Tommy Atkins graft can be seen on the right. The Tommy Atkins graft was simply not strong enough, nor aggressive enough to become well-established.
A scion from a Ruby Red Grapefruit was grafted onto a Hamlin orange tree. The grapefruit, growing much faster than the orange, took over and dominated the tree. The tree now appears to have been top-worked to change it into a grapefruit. However, that wasn't our intent when we placed one small grapefruit graft on a six foot orange tree.
A scion from a Marsh Grapefruit was grafted onto the left side of the orange tree, and the grapefruit overtook, outgrew, and dominated the orange to the point that the tree appears to have been a grapefruit from the beginning.
A couple of sprouts came up from the base of an Annona squamosa tree. We grafted scions from an Atemoya tree onto the squamosa about a foot above the ground. In less than a year, the Atemoya grafts grew to be almost as high as the squamosa tree. The atemoya appears to grow faster than the squamosa, and we suspect that it will eventually be a larger tree than the squamosa, if we permit it to do so.
The moral of the story is that as the years pass, one variety will generally become dominant over the other. So, to avoid future surprises, try to learn which are dominant varieties and be sure that you want the dominant variety before you start grafting different varieties onto the same tree.
DATE: November 2000
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