defoliate

Defoliate is a verb meaning to cause leaves to fall from a plant, or to remove foliage. The related noun defoliation refers to the process, and the adjective defoliant describes an agent that induces defoliation. The term comes from the Latin folium, leaf, with de- indicating removal.

Defoliation occurs naturally in deciduous plants during autumn and can result from disease, insect feeding, drought, nutrient deficiency, or extreme weather. It is also an intentional agricultural practice to hasten harvest, manage crop growth, or improve pest control.

Methods range from mechanical defoliation (physical removal of leaves, for example by hand or with equipment) to chemical defoliants, which are chemicals applied to plants to induce leaf drop. In cotton farming, chemical defoliants help to drop leaves before mechanical harvesting. Common chemical defoliants include synthetic auxins such as 2,4-D and other compounds; their use is regulated due to risks to workers, non-target plants, and ecosystems.

Defoliation can reduce photosynthesis and affect yield or plant health, and it can have environmental and health implications for organisms exposed to defoliants. Some defoliants have been restricted or banned in many regions due to toxicity and persistence.

Historically, defoliation has broader implications beyond agriculture, including its use in military contexts to remove forest cover, most notably with defoliants used during the Vietnam War. Modern practice emphasizes safety, environmental stewardship, and regulatory compliance.