All of lower growth Is dead

All my lower growth is dead ...i got a 4x4 sour d and i dnt knw weather if its because they get too much sun or wat ???... I would say a good 2ft is just large stems with no leaves or nothing ..all of the top seems to be doing good but getting downer its all just skeleton .. Dnt knw wats gonig wrong ????

Pics, details, feeding, etc.

Without pics and details I'd guess it needs some nitrogen. Or if it has frozen maybe the bottom leaves got frostbitten and died. Just a hypothesis

Well bud, I really wouldn't sweat it. The season has pretty much come to a close, and it's expected to lose most to all of the fan leaves by the end of flower.