To prevent contaminating lower pant leg, trouser legs should:

Wearing trouser legs inside of boots is the correct approach to prevent contaminating the lower pant leg. This method effectively creates a barrier that helps keep pesticides, dirt, and other contaminants from splashing or transferring onto the leg, which is crucial for maintaining proper safety and hygiene practices while applying pesticides.

When pant legs are tucked into boots, it reduces the risk of exposure to chemicals that may be present on the ground. This protective measure is especially important when working in environments where pesticides are used, as it minimizes the likelihood of skin contact with harmful substances.

Additionally, wearing pants outside of boots could potentially allow for easier access to contaminants, while rolling up trouser legs does not provide adequate protection from pesticide splashes. Opting for shorts would increase skin exposure to the environment and any chemicals present, making it far less safe. Hence, tucking trouser legs inside boots is the best practice for personal protective equipment in this context.