It’s important to start shaping the tree immediately after planting. Determine the desired height of the first branching, taking into account aesthetics, proper clearance for equipment, etc. An initial branching height between two to three feet is appropriate. A single cut is made at this point. Soon multiple, leafy branches will grow from the buds just below the initial cut. Of these, save three or four horizontal shoots, spaced equally around the stem. Upright shoots should be removed. The chosen horizontal shoots will form the main scaffold limbs of the tree.
These shoots should be allowed to grow to about 20 inches long, a length generally reached during the second flush of leaves. The flush can be pinched off with the fingers at this time, or left to mature and then pruned with hand-held pruners (heading). Multiple shoots will grow from the buds below the cut. Allowed them to extend about 20 inches and then head them. Continues this procedure through the second year. If selected shoots grow vertically, pull them down by attaching commercial branch weights or suspending heavy objects from a string. The weights should be left on for about three months. Horizontal scaffold limbs are stronger and flower and fruit earlier. Inspect the tree often and remove excessively vigorous vertical shoots in favor of horizontal shoots. After three years, the short branches within the tree canopy will produce a complex, compact, strong structure.
You can expect fruiting in the second or third year after planting. Fruiting is one of the best tools for maintaining tree size: The tree’s energy is diverted from wood development into fruiting. Immediately after harvest, prune the tree, heading the small branches to a length of 20 inches and favoring horizontal shoots. In vigorous cultivars, even with close attention to proper pruning, trees will develop large, structural limbs which divert energy from fruit production. “Thinning cuts” can be used annually to remove a portion of this wood. Thinning cuts are made by removing an entire limb. These cuts affect the vigor of the tree less, allowing the homeowner to maintain a “calm” tree, one with adequate, but not excessive vegetative growth. Typically, one major limb is removed per year, renewing the canopy every four to five years.
If you follow these basic rules, you can maintain a mango tree as a small, productive tree throughout its life. Perhaps the most effective management technique is a daily walk through the home landscape to observe and monitor the development of your trees. Take the time, while in front of the tree, to pinch or prune. Do not wait for the perfect time. Failure to manage growth will result in an out-of-control tree, one which is difficult to bring back under control.
Remember, management starts early in the life of the tree and continues indefinitely.
http://www.virtualherbarium.org/TropicalFruit/mangopruning.html, 13 Jan 2013.