Which of the following is NOT a method of monitoring the effectiveness of fumigation?

Monitoring the effectiveness of fumigation involves assessing factors that directly relate to the efficiency of the fumigant and its impact on pest populations. Gas detection monitoring allows applicators to measure the concentration of the fumigant in the environment, ensuring that it remains at effective levels for the target organism. Tracking pest population changes post-fumigation provides insight into how successful the treatment was in reducing pest numbers. Time-based monitoring of exposure is critical to determining whether the fumigant was applied for the right duration and under appropriate conditions.

In contrast, a change in soil pH does not directly relate to monitoring the effectiveness of fumigation. While soil pH can impact plant health and the behavior of certain pests, it is not an indicator of how well a fumigant has performed in eliminating pests. Therefore, it does not serve as a reliable or relevant method for assessing fumigation effectiveness.