it means the crown is going wild (i.e cheering and stuff)

'To go bananas' is an idiom which can mean to go crazy, to behave in an irrational way, to suddenly become very angry, overly excited or emotional. Many people believe the idiom originates from the fact that bananas, like any fruit, ferment on the ground if left for a time. When monkeys eat them they become intoxicated on the fermented alcohol and start acting very excited and drunk. There is also the belief that it originates from a rumour in the 1960s that it was possible to smoke burnt banana peel and get high.

go bananas = go crazy

Bananas = crazy!