Stumped by some of the longer clues.
22a Main source of energy and power: runner holding record (5,5)
P?i?e ???e?
24d Replacing of erne that's taken out faster bird of prey (9,6)
Looks like 'peregrine falcon'.
26d Cripes! Trouble with root vegetable amongst cabbage? Possible culprit (8,6)
Colorado beetle?