Which method of pest control is primarily preventive rather than curative?

The use of protectant fungicides is primarily preventive rather than curative because these fungicides are designed to create a barrier or film that prevents fungal pathogens from entering through plant surfaces. This preventive approach helps to avoid infection before it occurs, making it an essential strategy in managing plant health, especially in agricultural settings where the risk of fungal infections is high.

In contrast, other methods such as the application of residual insecticides or contact insecticides target pests that are already present. These methods are more about controlling existing pest populations rather than preventing their arrival. Similarly, a systemic approach may involve treating a plant to deal with an ongoing infestation rather than proactively ensuring that pests do not become a problem in the first place. Thus, the proactive nature of protectant fungicides aligns with the goal of preventing disease outbreaks, distinguishing it clearly from curative methods.