What is a method of mechanical control?

The correct answer is physical barriers because this method directly involves using tangible materials or structures to prevent pests from accessing plants or crops. Physical barriers can include screens, netting, or row covers that limit pest entry while allowing sunlight and moisture to reach the plants. This approach minimizes the need for chemical pest control and supports integrated pest management practices.

In contrast, fertilization involves the addition of nutrients to the soil to promote plant growth and does not serve as a direct method of pest control. Genetic engineering refers to altering the genetic makeup of organisms to enhance certain traits, which may lead to pest resistance but is not purely a mechanical method. Crop selection involves choosing specific plant varieties that are less susceptible to pests, which is more of a biological and management strategy rather than a physical barrier to pest entry.