Which term describes a chemical that causes leaves to drop?

• A. Defoliant
• B. Contact
• C. Systemic
• D. Pre-plant

Answer: (A)

A defoliant is a chemical designed to cause leaves to shed from a plant. It’s used to facilitate harvest by speeding leaf drop, often by weakening the leaf attachment or drying out the leaf tissue so the leaves fall more easily. The other terms describe how a chemical acts or when it’s applied, not the specific outcome of leaf drop: contact refers to action only on tissues it touches, systemic means the chemical moves through the plant, and pre-plant indicates timing relative to planting. Defoliant directly names the purpose of causing leaves to drop, which is why it’s the best fit.