Possible Clues:

• "Put ye in the sickle, for the harvest is ___" (Joel 3:13)
• Sufficiently aged
• Suitable letters attached to name after passing English
• Band ready for the big time
• Mature, like fruit
• Mature, ready for eating
• Suitable
• Ready reckoner is proof enough -- initially
• Ready (to be eaten or used)
• Complaints with no case ready for action