Which physical control method can be used to prevent pest entry?

Installing row covers is an effective physical control method used in pest management to prevent pest entry into growing crops. Row covers are lightweight fabric materials that are placed over plants to create a physical barrier, which helps protect them from various pests, such as insects and some animals. This method not only prevents these pests from accessing the plants but also can provide some level of temperature regulation and protection from harsh weather conditions.

In contrast, planting pest-attracting flowers is not a preventive measure; instead, it can potentially draw pests closer to the crops. Using insect vacuums is more of a reactive control strategy that involves removing pests once they have been identified, rather than preventing their initial entry. Employing selective insecticides is a chemical control method that is aimed at managing pests that are already present rather than stopping them from entering an area in the first place. Therefore, row covers offer a proactive and effective way to minimize pest threats.