Commodity Fumigation License Practice Exam

What happens to fumigants when soil temperatures are above 70 degrees?

1. They penetrate slowly throughout the soil

2. They remain effective for a longer period

3. They volatilize and penetrate too quickly for adequate pest control

4. They become ineffective

The correct answer is: They volatilize and penetrate too quickly for adequate pest control

When soil temperatures rise above 70 degrees Fahrenheit, fumigants tend to volatilize more rapidly. This increased volatility can lead to the fumigants penetrating the soil at speeds that do not allow for sufficient interaction with the pests present in the soil. Adequate pest control relies on maintaining the fumigant at the target site for a specific duration, allowing it enough time to act on the pests; however, excessive volatility can significantly diminish this contact time. Consequently, this can render the treatment less effective because the critical exposure time needed to control pests may not be met, ultimately resulting in insufficient pest elimination. Higher temperatures can also affect the dynamics of the fumigants in terms of how they disperse in the soil, which can further compromise their effectiveness by reducing the concentration levels necessary to achieve successful pest control. Thus, the relationship between temperature and fumigant behavior is crucial in ensuring that the treatment is performed under optimal conditions for effective pest management.