malhomme

I would trim the longer needles. You will get brown tips, but it will weaken the area (which is growing too vigorously). To further balance the vigor of the upper and lower portions of a healthy tree:

1. Strong vigor areas: reduce the number of needles by cutting some of the needles back to the sheath. Three or four pairs of needles should remain on strong shoots.
2. Medium vigor areas: same procedure as above (1), but leave five to seven needle pairs
3. Weak vigor areas: same procedure as above (1), but leave all of the needles in the weak areas. Expose this portion the tree to more sunlight.
4. Give your tree some of groceries (fertilizer) to awaken sleeping buds.

I hope this helps.

Kind regards,
Jim