Top performers regularly at the farm (1-4)
I believe the answer is:
a-team
'top performers' is the definition.
(I've seen this in another clue)
'regularly at the farm' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'at'+'the'+'farm'='atthefarm'
The alternating letters of 'atthefarm' are 'A-TEAM'.
(Other definitions for a-team that I've seen before include "top people" , "Elite group of soldiers or workers" , "Elite troops" .)