Close examination of Southern vineyard, very small (8)
I believe the answer is:
Here is my best explanation:
'close examination' is the definition.
(I've seen this before)
'southern vineyard very small' is the subsidiary indication.
'southern' becomes 's' (abbreviation).
'vineyard' becomes 'cru' (I've seen this in other clues).
'very small' becomes 'tiny' (I've seen this before).
'of' is the link.
(Other definitions for scrutiny that I've seen before include "City runs (anag.)", "From close inspection", "A careful look or examination", "Close, careful examination", "Close survey", "Critical examination", "Close investigation", "Examination", "Detailed perusal" and "Investigation".)