California Applicator License Category D Plant Agriculture Practice Test

Rotating pesticides by mode of action groups helps resistance management by preventing pests from being exposed to the same target site over and over. When a single mode is used repeatedly, pests with resistance traits survive and reproduce, gradually creating a resistant population. Using products that affect different targets in the pest’s biology keeps the selection pressure low on any one site, slowing the development of resistance and helping maintain efficacy as part of an overall IPM approach. The other practices push resistance by either giving pests the same target site repeatedly, ignoring how products work, or increasing pressure with the highest rate, none of which effectively slows resistance.