Commodity Fumigation License Practice Exam

In what situation should fumigants be applied with caution regarding temperature conditions?

1. When soil temperature is below 40 degrees

2. When soil temperature is above 70 degrees

3. Both A and B

4. When soil temperature is between 40-70 degrees

The correct answer is: Both A and B

Fumigants must be applied with caution in temperature conditions both below 40 degrees and above 70 degrees due to the impact temperature has on the efficacy and behavior of the chemicals used in fumigation. When soil temperature is below 40 degrees, the effectiveness of fumigants can be reduced significantly. Lower temperatures can slow down the metabolic processes of pests, making them less responsive to the fumigants and decreasing the likelihood that the treatment will penetrate effectively into the soil or target pests. Conversely, when soil temperature is above 70 degrees, there may be concerns with the volatility of the fumigants. Higher temperatures can cause the chemicals to evaporate more quickly, which can lead to insufficient concentrations being present to adequately control pests. Additionally, high temperatures can increase the risk of phytotoxicity, causing damage to crops or soil organisms. Thus, both extremes of temperature require careful consideration to ensure that fumigants are applied effectively and safely, making the choice indicating that caution should be exercised in both conditions the correct one.