Antonym of preventive

Suitable word which has meaning “taking care of agricultural plants after the damage (affected by virus or some other insects)has happened” Taking steps before damage happens is “preventive” then what is the antonym for “preventive”

Preventive (prevent + -ive) is an adjective formed from a verb prevent and suffix -ive (-ive is word-forming element making adjectives from verbs). Here, prevent means an "act in anticipation of", it comes from Latin praeventus, past participle of praevenire meaning "come before, anticipate, hinder". So, preventive actions is taken before [something bad] may happen.

The action to restore the current state of [something] to its previously healthy state after [something bad] happens must be remedial action. Remedial is an adjective formed from a noun remedy. Whereas, remedy is re- and mederi, mederi means "to heal". Unlike -ive, re is a prefix meaning "back to the original place; again, anew, once more," also with a sense of "undoing".

The word which acts as an antonym to preventive is remedial. It means, "curing, relieving, affording a remedy," from Late Latin remedialis "healing, curing," from Latin remedium "a cure, remedy, medicine, antidote, that which restores health.

So, in summary, Preventive action is taken before [something bad] may happen and Remedial action is taken after [something bad] happens.

Merriam Webster defines 1 remedial as: intended as a remedy.

Remedy: a medicine, application, or treatment that relieves or cures a disease

Oxford dictionary defines 1 remedial as: Giving or intended as a remedy or cure.