SDHI's limited lifespan
The industry's response to the loss of efficacy of triazoles is to rely on mixing triazoles (Gleam, Prosaro, etc.) and also using other actives like SDHI chemistry and chlorothalonil.
To date testing of SDHI chemistry has shown that septoria populations are still sensitive to the fungicide group and chlorothalonil is still a very effective protectant fungicide against septoria.
The application of all three chemicals' groups through the fungicide programme will help to prolong the effective use of triazoles and SDHI chemistry.
The scientific community believe SDHI chemistry has a limited life (a short few years) before septoria becomes resistant to controls and growers should be doing all they can to protect this chemistry.
The table below outlines the main chemicals used at different timings in winter wheat.