In foliar application, where is the pesticide applied?

The correct option indicates that, in foliar application, pesticides are specifically applied to the leafy parts of plants. This method is designed to ensure that the active ingredients of the pesticide can be effectively absorbed by the plant leaves. The foliage is the primary site for the application because it is where pests commonly feed and where plant diseases often manifest.

Moreover, applying pesticides to the leaves allows for quicker absorption into the plant's system, providing fast action against pests that are on or in contact with the leaves. This application technique can also prevent damage to the plant’s root system, which can occur when chemicals are applied directly to the soil or root zone.

In summary, foliar application targets the leaves because this approach maximizes the efficacy of the pesticide against pest populations while minimizing potential harm to other parts of the plant.