Pressman backing into barn with small cultivators (9)
I believe the answer is:
gardeners
'cultivators' is the definition.
(people who cultivate plants)
'pressman backing into barn with small' is the wordplay.
'pressman' becomes 'ed' (short for editor).
'backing' shows that the letters should be reversed in order.
'into' means one lot of letters goes inside another.
'barn' becomes 'garner' (garner can mean a store for grain).
'with small' becomes 's' (abbreviation - e.g. clothes size. I am not sure about the 'with' bit.).
'ed' in reverse letter order is 'de'.
'de' put within 'garner' is 'gardener'.
'gardener'+'s'='GARDENERS'
(Other definitions for gardeners that I've seen before include "Land workers" , "Perhaps nursery workers" .)