Which combination of factors can contribute to increased pesticide resistance?

The selected answer highlights a critical issue in pest management practices—low dosage and frequent use of a pesticide can indeed lead to increased pesticide resistance among pest populations. When a pesticide is used at low dosages, it may not be sufficient to kill all individuals in a pest population. Those that survive may possess or develop genetic traits that confer resistance to that pesticide. If the same pesticide is applied frequently, it exerts consistent selection pressure on the pest population, allowing resistant individuals to thrive and reproduce, further perpetuating the cycle of resistance.

In contrast, using high diversity of chemical products, practicing integrated pest management, and incorporating breaks in application between crops are strategies that promote resistance management. High diversity of chemical products reduces the likelihood of resistance because pests are exposed to different modes of action. Integrated pest management employs a variety of control methods, further mitigating the risk of resistance. Similarly, breaks in pesticide application allow time for the susceptible pest population to recover and reduce the overall selection pressure for resistance, thereby assisting in managing pest populations more effectively.