What is the importance of plant health for fungicide effectiveness?

Plant health means a balanced supply of nutrients, minimal energy loss, and maximum conversion of available energy into grain production. When a fungicide is applied to a healthy plant, the processes involved in protection — such as absorption, metabolism, and fungicidal action — are quickly activated, resulting in strong protection. When this efficient protection is supported by readily available defense mechanisms, the outcome is maximum effectiveness.

On the other hand, when the plant is already infected by pathogens, both its natural defenses and the processes related to fungicide application tend to deliver weaker results. This happens because the plant’s physiology cannot supply enough secondary compounds responsible for fighting the pathogen. With weaker defense activity, the demand for control shifts almost entirely to the fungicide. Combined with metabolic limitations, this leads to lower effectiveness.

This is the key reason why preventive management is critical: protecting plants at the early stages of a disease ensures higher fungicide efficiency and better field results, without compromising the physiology of a high-yielding crop.