What should be done to avoid pesticide movement into the root zone of nontarget plants?

The correct answer focuses on ensuring correct application timing as a critical factor in minimizing pesticide movement into the root zone of nontarget plants. Proper timing helps to match pesticide application with environmental conditions such as wind speed, temperature, and moisture levels. This alignment reduces the likelihood of drift and runoff, which can transport pesticides beyond the intended application area and into the soil where nontarget plant roots may absorb them.

For example, applying pesticides during dry weather with low wind conditions can limit the possibility of the chemicals being carried off by environmental factors. It is also focused on the growth stages of target plants; applying during stages when target plants can effectively utilize the pesticide without risking surrounding flora is essential.

Higher concentrations of pesticides might increase the risk of leaching or moving into the soil, while more granular forms of pesticides may not necessarily prevent movement if conditions are not favorable. Selective pesticides can reduce harm to nontarget species but do not directly address the application timing aspect that is crucial for preventing unwanted movement into root zones.