If I were to prune a branch, it would interrupt the flow of auxin in the cambium and release buds below that have been held in stasis (of course there must be cyokinins in the tissues below to release the buds; i.e., the plant is actively growing). If instead I girdled the branch, I would also interrupt the flow of auxin to the tissues below and this ought to release buds in stasis just like decapitating the branch.
Am I right/wrong that girdling and pruning are equivalent in this respect (and why please)? In other words, is girdling and pruning equivalent as far as the response of the rest of the plant is concerned?
Girdling is removing a ring of bark completely around the stem. This also removed the phloem or inner bark in which sugars from photosynthesis are transported down the tree from the foliage toward the roots. This also removes nearly all of the vascular cambium through which auxin is transported from cell to cell (like a bucket brigade). However within a day or two exposed to the air any residual cambium cells desiccate and die - in effect, girdling also removes all of the cambium. The xylem (wood) remains in tact, supplying water and minerals to the portion of the branch above the girdle.
A girdle cuts off the flow of auxin to the branch just below the girdle as well as sugars from above. Pruning cuts off the flow of auxin and sugar as well. Yet many people tell me that pruning will release more buds than making a girdle. I cannot understand how this could be true. Is the effect really different? And if it is, I am very interested in an explanation of why.