When you are deciding whether to use an intervention, you should think about whether it is more helpful than harmful, not just whether it is helpful. This depends on the size of the good and bad effects.
The size of the effects may depend on how severe you problem is (e.g. a pest problem) or how likely it is to occur (your baseline risk).
It also depends on how important the outcomes are. For example, a particular pest control method may reduce pests, but may also reduce the number of natural enemies. Some people might think that it is more important to completely eradicate the pest even if it means treating the crop more frequently, whereas others may prefer to accept a low incidence of pest damage, and so be less likely to use that pest control method.
REMEMBER: Ask yourself if the advantages outweigh the disadvantages.