What are dormant oils used for in pest control?

Dormant oils are primarily utilized in pest control during the dormancy period of deciduous plants, which typically occurs in late fall to early spring. The main purpose of applying dormant oils is to control pests and diseases that may overwinter on the plants. During this dormant phase, plants are not actively growing, making it an optimal time for treatment since the oils can suffocate overwintering insects, such as scale and mites, as well as their eggs and fungal spores.

The effectiveness of dormant oils lies in their ability to coat and smother pests while causing minimal harm to the plants themselves, as they are not in a growth phase. This preventive method helps to reduce pest populations before the growing season begins, leading to healthier plants when spring arrives.

In contrast, other options focus on pest control during active growth or operational phases, which do not align with the specific purpose of dormant oils. Applying oils to enhance stickiness is also a different application and does not pertain specifically to the unique use of dormant oils, which is focused on the off-season management of pest populations.