Which ingredient helps an active ingredient stick or spread better?

The correct option is an inert ingredient, which plays a crucial role in the formulation of pesticides. Inert ingredients are substances that do not have pest control activity themselves but enhance the effectiveness and stability of the active ingredients. They can improve adhesion to plant surfaces, increase spreading and wetting properties, and help the active ingredient remain effective for a longer time.

Inert ingredients might include surfactants, emulsifiers, and stickers that facilitate better coverage and penetration of the active ingredient within the target area. They optimize the performance of the pesticide formulation by ensuring that the active ingredient can effectively reach the pests it is designed to eliminate.

Other components like the active ingredient are crucial for the pest control itself but do not assist in sticking or spreading. Solvents primarily serve to dissolve or dilute the active ingredient for better application but do not enhance the adherence. An agitator is a tool used during mixing and application; it helps ensure uniformity of the mixture but does not have a role in the sticking or spreading of the formulation on surfaces. Thus, the presence of inert ingredients is essential for maximizing the performance of pesticides by improving their adhesion and distribution.