Growth in agenda oddly bearing fruit (7)
I believe the answer is:
acorned
'growth in' is the definition.
The definition suggests an adjective which matches the answer.
'agenda oddly bearing fruit' is the wordplay.
'oddly' indicates alternate letters (letters in odd-numbered positions).
'bearing' indicates putting letters inside.
'fruit' becomes 'corn' (corn is a kind of fruit).
The alternating letters of 'agenda' are 'aed'.
'aed' placed around 'corn' is 'ACORNED'.
Can you help me to learn more?
(Another definition for acorned that I've seen is " ready to produce more oaks?".)