What type of pesticide is primarily used to eliminate moisture from plant tissue?

Desiccants are chemicals specifically designed to promote the loss of moisture from plant tissues, thereby drying them out. These substances work by drawing moisture away from the plant, effectively dehydrating it. This action can be critical in certain agricultural practices, especially in preparing crops for harvest or controlling diseases by promoting rapid drying.

In contrast, growth regulators modify plant growth processes but do not primarily focus on moisture elimination. Defoliants are used to trigger leaf drop and may indirectly affect moisture levels in the leaves but are not specifically designed to remove moisture from plant tissues. Repellents work to deter pests from feeding on plants, which does not relate to moisture content in plant tissue. Therefore, the use of desiccants highlights their primary function in moisture removal, making them the correct choice in this context.