What is a defoliant primarily used for?

A defoliant is a chemical agent specifically designed to induce the dropping of leaves from plants. This process is often employed in agricultural practices, especially in crops where premature leaf drop is desirable to facilitate harvesting. For example, in cotton production, defoliants are used to promote the shedding of cotton leaves before harvest, allowing easier access to the cotton bolls.

The primary function of defoliants is to disrupt the normal physiological processes of the leaves, leading to their abscission. This is crucial for achieving optimal harvest timing and improving overall crop management.

In contrast, the other options focus on different plant functions: promoting growth and enhancing seed production involve supporting the plant's life cycle and productivity rather than removing leaves, while preventing disease is a separate aspect related to the health and protection of the plant.