Right and wrong
Right: To remove a branch for whatever reason (beauty, safety, light, flowers and fruits), use a pruning saw to make a smooth cut, allowing the bark to overgrow the wound with no delay. This will minimize the risk of a fungal attack and make a more beautiful stem.
Wrong: Do not use a machete knife to whack the branch. The stump of the branch may take years to die/decompose, and cracks and the rough surface will increase the area for pathogenic fungal spores to land and thrive. An invasive pathogenic fungus may wipe out the entire tree and then spread from gnawing roots to other trees.
If you saw from the top only, a heavy branch may rip off the bark below the branch and expose more wood. Use the saw to make an initial cut from below until 30-50% deep, then make a top cut until the branch breaks. Finally, make a third cut to remove the stump.
There is no need to cover the wound with a paste.
Text & Photo: Eric Danell and a Dokmai Garden longan tree (Dimocarpus longan, Sapindaceae).