In which situation should shielding devices be used during herbicide application?

Using shielding devices during herbicide application is particularly important when applying near emerging crops. This practice minimizes the risk of herbicide drift, which can damage or kill nearby crops that are sensitive to the applied chemicals. Shielding devices act as barriers that deflect the spray away from the non-target plants, ensuring that the intended area receives the treatment while protecting vulnerable vegetation.

The other contexts presented, such as reducing application costs, the absence of winds, or using granular formulations, do not necessitate or specifically call for the use of shielding devices. While cost-effectiveness is important in agricultural practices, it does not directly relate to protecting non-target plants during the application. Similarly, when winds are absent, the risk of drift is significantly reduced, making the use of shields less critical. Granular formulations also do not generally require shielding as they are less likely to drift compared to liquid formulations. Therefore, the best practice is to use shielding devices particularly when applying herbicides close to emerging crops to prevent unintended damage.