Ethylene Posted on November 8, 2022August 1, 2023 by Tex Norwood Is the only hormone that is a gas. It speeds aging of tissues and enhances fruit ripening. Related Images:Related Articles: Grafting and Budding OverviewGibberellic Acid for Fruit Set and Seed GerminationGlossary: Slow Release FertilizerPlant hormonesVisit our InfoTIP Glossary