What does the term 'systemic' refer to in pesticide application?

The term 'systemic' in pesticide application refers to a compound that is absorbed and distributed throughout the plant. This means that once a systemic pesticide is applied, the plant takes it up through its roots or leaves, allowing it to move through the plant's vascular system. As a result, the pesticide becomes effective in controlling pests that feed on various parts of the plant, including the leaves, stems, and roots.

This characteristic is particularly advantageous when dealing with pests that are difficult to reach through surface applications. Systemic pesticides offer a more comprehensive solution since they can target pests that might otherwise evade direct contact with the pesticide. This mode of action enhances the effectiveness of pest control strategies, especially for internal feeders like certain types of borers or sap-sucking insects.

In contrast, other options describe different aspects of pesticide interaction or application without accurately capturing the comprehensive nature of systemic pesticides. For example, applying a pesticide only to the surface does not involve the plant uptake mechanism, while targeting specific pests pertains to application strategies rather than the chemical nature of the pesticide itself. Additionally, mentioning a pesticide that remains active in the soil focuses on residual activity rather than its ability to be absorbed and distributed within the plant.