Which of the following methods can help reduce spray or vapor drift?

Choosing a lower boom height is beneficial in reducing spray or vapor drift because it shortens the distance between the nozzle and the target area. By having the spray closer to the plants or soil, there is less chance for droplets to be carried away by wind after exiting the nozzle. This method helps increase the likelihood that the herbicide will land on the intended area rather than drift away, which can be especially important for protecting non-target plants and the surrounding environment from unintended exposure.

In contrast, other methods like using narrower nozzle tips can potentially lead to smaller droplet sizes, which may increase drift rather than reduce it. Higher spray pressures can also create finer droplets that are more susceptible to drifting due to wind. Finally, using a single nozzle opening could limit coverage and may not effectively control the target area, but it does not directly assist in reducing the risk of drift. Therefore, maintaining a lower boom height is a practical and effective approach to mitigating spray drift during herbicide application.