It's called pruning
And it’s also called training your plant to adhere to the inverse square law of artificial lighting.
double the distance and you half the light.
I like to train and prune so that I leave around 1.5-2ft of plant Material within the useable penetration of my light.
1000w light approx 4ft of penetration
600w light approx 3ft penetration
400w light approx 2ft of penetration
250w light approx 1ft penetration.
what this means is anything over this penetration limit will not grow as intended.
leave it grow is fine if you’re dealing with a 1000w light and 1 plant.
each light has a maximum active growing area.
1000w 5ft x 5ft (approx)
600w 4ft x 4ft
400w 3ft x 3ft
250w 2ft x 2ft
The idea being that you want all of your bud sites to be within the penetration and active growing area of the lighting you’re using.
this is mainly for HPs as I don’t utilise LED So couldn't possibly Comment on penetration and active area of LED’s.