Unproductive anger follows setter regularly leaving bits out (7)
I believe the answer is:
sterile
'unproductive' is the definition.
(unable to reproduce)
'anger follows setter regularly leaving bits out' is the wordplay.
'anger' becomes 'rile' (rile can mean to annoy or anger).
'follows' says to put letters next to each other.
'regularly leaving bits out' means one should take alternating letters.
The alternating letters of 'setter' are 'ste'.
'rile' after 'ste' is 'STERILE'.
(Other definitions for sterile that I've seen before include "Fruitless" , "Unable to have children" , "Uninspired" , "Like theatre" , "Ineffective" .)