The term 'ripening agents' refers to substances that are used to speed up the ripening process of fruits and vegetables. The crossword solutions for this term are AGERS, which is an acronym for ethylene, acetylene, gibberellins, and respiration inhibitors. Ethylene is a naturally occurring hormone that helps to trigger the ripening process in fruits and vegetables. Acetylene is a synthetic compound that can also be used to speed up the ripening process. Gibberellins are plant hormones that can be used to promote the growth and ripening of fruits and vegetables. Respiration inhibitors are compounds that slow down the respiration rate of fruits and vegetables, which can help to preserve them for longer periods of time.