Twigathalonil is a broad spectrum non-systemic fungicide effective for the control of a wide range of fungal diseases in vegetables, flowers and coffee. It acts by protecting plants against fungal infection.

Accordingly, for best disease control the fungicide must be present on the plant prior to an onset of infection. Infection is presented as a result of certain interactions between chlorothalonil and fungal cells, which ultimately result in loss of cell viability.