What factor is least likely to influence the effectiveness of pest control through fumigation?

The least likely factor to influence the effectiveness of pest control through fumigation is worker experience. While experienced workers can certainly perform fumigation tasks more efficiently and safely, the fundamental effectiveness of the fumigation process primarily relies on other factors.

For instance, the type of pest plays a crucial role, as different pests may have varying tolerances to specific fumigants. Soil temperature can significantly affect the diffusion and efficacy of fumigants; warmer temperatures often enhance gas mobility and activity. The duration of tarp application is also vital, as keeping the fumigant contained for an adequate period ensures it can effectively penetrate and eliminate the pests in the treated area.

Therefore, while worker experience contributes to the overall process, it does not directly affect the chemical and environmental factors that are critical to the success of fumigation treatments.