Is applying a fungicide at half of the label rate a recommended resistance management practice?

Applying a fungicide at half of the label rate is not considered a recommended resistance management practice. The primary goal in resistance management is to ensure that the efficacy of fungicides remains high and to delay the development of resistance among target pathogens.

When fungicides are applied at sub-lethal rates, such as half of the recommended label rate, there is a risk that pathogens may be exposed to insufficient concentrations of the active ingredient. This under-dosing can allow some spores or fungus strains to survive and potentially develop resistance to the fungicide, making it less effective in the future. Therefore, following the label rate is critical to achieving effective control and minimizing the risk of resistance development.

In contrast, fully adhering to the label rates not only optimizes the effectiveness of the fungicide in controlling the targeted pathogens but also supports integrated pest management strategies, which aim to maintain long-term efficacy of control measures and protect crop health.