There is an array of antonyms for the phrase "make fruitful," such as "blight," "impair," "ruin," "barren," "sterile," "unproductive," and "fruitless." These terms indicate a lack of prosperity, abundance, or productivity. While making something fruitful entails nurturing, cultivating, or enhancing it, these antonyms suggest stagnation, decay, or destruction. The opposite of making something fruitful is often characterized by failure, disappointment, and wasted efforts. Therefore, it's crucial to understand the context in which these antonyms are used to grasp their impact on the meaning of a sentence or phrase thoroughly.