It's all good except for "a long of the pole."
"Of the pole" would refer to a property of the pole. Note that the properties listed below are all nouns (length, strength) rather than adjectives (long, strong).
the pole's strength the strength of the pole
the pole's flexibility the flexibility of the pole
the pole's length the length of the pole
the pole's use the use of the pole
The greater length of the new pole allows him to harvest the mangos he had been unable to reach before.