What effect do herbicidal defoliants such as Folex have on the plant?

Herbicidal defoliants like Folex are specifically designed to cause leaves to drop from plants, which is particularly beneficial for cotton harvesting. When these defoliants are applied, they cause the plant to experience stress, which stimulates the production of ethylene, a plant hormone that plays a critical role in processes such as fruit ripening and leaf abscission (the shedding of leaves).

The increase in ethylene levels prompts the plant to shed its leaves, making it easier to harvest cotton by reducing the amount of leaf material that can interfere with harvesting equipment. This process does not stimulate growth or induce dormancy; rather, it induces a response that allows for a more efficient harvest. Hence, the most accurate characterization of the effect of these herbicidal defoliants on the plant is that they initiate stress responses, leading to increased ethylene production, which in turn promotes leaf drop.