Which condition should be avoided to prevent pesticide drift?

The correct choice highlights that high humidity conditions should be avoided to prevent pesticide drift. When humidity levels are high, more water molecules are present in the air, which can affect how droplets of pesticide behave once they are released. High humidity can lead to a situation where pesticide droplets do not evaporate as intended and may form a mist that can drift away from the targeted area. This drift can cause unintended exposure to surrounding plants, animals, or humans, leading to potential harm.

In contrast, low wind speeds and calm weather are typically conditions that help reduce the risk of drift. With low wind speeds, there is minimal air movement to carry pesticide particles away from the application site, while calm weather indicates stable air, again reducing the likelihood of drift. Low temperatures can also contribute to pesticide drift indirectly but are often not as directly impactful in the same way that high humidity is. Thus, understanding the effects of humidity on pesticide application is key in ensuring safety and efficacy in pesticide use.