The season to introduce a final way for applying water (8)
I believe the answer is:
spraying
'applying water' is the definition.
I can't tell whether this definition defines the answer.
'the season to introduce a final way' is the wordplay.
'the season' becomes 'spring' (spring is a season).
'to introduce' is an insertion indicator (to introduce to can mean to insert or include).
'final' says to take the final letters.
The final letter of 'way' is 'y'.
'a'+'y'='ay'
'spring' enclosing 'ay' is 'SPRAYING'.
'for' is the link.
Can you help me to learn more?
(Another definition for spraying that I've seen is " Dispersing insecticide on crops, say".)