Which factor does not typically impact pesticide effectiveness?

The personal preference of the user does not typically impact the effectiveness of pesticides because effectiveness is largely determined by objective factors related to pesticide formulation and environmental interactions. Factors like environmental conditions—which can include temperature, humidity, and wind—directly affect how well a pesticide works, influencing the pesticide's evaporation rate and longevity on the target site. The application method used, such as whether it's sprayed or applied as granules, can also determine how well the pesticide reaches the pest or the plant, affecting the overall outcome.

Similarly, the crop type being treated matters greatly since different crops may have varying tolerances to pesticides, and certain pesticides are formulated specifically for certain crops to maximize effectiveness while minimizing potential harm. In contrast, personal preference is subjective and does not influence the chemical properties or behavior of the pesticide itself, thus rendering it a non-factor in terms of effectiveness.