What is one direct effect of using row covers on pest management?

Using row covers in pest management serves as a physical barrier to insect pests. This method is highly effective in protecting crops from a variety of insects that can cause damage. The covers prevent pests, such as aphids, beetles, and caterpillars, from reaching the plants, which can significantly reduce the need for chemical insecticides. By creating a physical obstruction, row covers help maintain plant health and yield, making them a valuable tool in integrated pest management strategies.

In addition to their pest-repellent properties, row covers can influence other factors related to plant growth and health. However, options that mention increased moisture retention, improved air circulation, or enhanced nutrient availability focus on other aspects that are not the primary function of row covers concerning pest management. These functions might occur as side effects but do not directly relate to the primary benefit of using row covers to manage and mitigate pest pressure on crops.