The Agricultural and Horticultural Development Board (AHDB) has highlighted the role for wheat varieties with improved resistance to disease.
The reality is that varieties with higher levels of disease resistance allow greater flexibility in fungicide programmes.
This includes the omission of sprays and the use of reduced doses, while still maintaining acceptable yield and quality.
But even with stronger disease resistance, AHDB analysts point out that environmental factors, disease pressures, and crop management practices still influence the effectiveness of reduced-input strategies.
However, if varietal resistance is high, weather is not conducive to disease, and fungicide applications are well-timed, lower-input approaches could help increase crop profitability.
In some cases, skipping T0 is feasible for resistant varieties, unless early disease pressure is high. But T1 and T2 applications remain crucial, especially for septoria tritici and rust management.
Meanwhile, the need for a T3 spray depends on fusarium and brown rust risks, as well as market requirements.
So, what is the general economic result of this crop management approach?
In overall terms, the higher the disease resistance ratings score for a specific wheat variety, the lower the risk of unacceptable losses.
Wet and humid weather conditions tend to drive disease pressures, which may require a more robust fungicide programme. Many farm-specific risk factors affect crop susceptibility, including cultivation, rotation, drilling date, regional disease trends, and spraying capacity.
Numerous AHDB research projects have examined these factors in detail, with most focusing on septoria tritici. One study showed how sowing dates influence recommended list disease ratings for this specific disease.
When sown early (average sowing date September 22), the effective disease rating decreased by about 0.6. This is because crops were consistently associated with higher disease severity during the main yield-forming period.
Conversely, when sown late (average sowing date October 20), the effective disease rating increased by 0.6.
This shows how a flexible, risk-based approach can underpin efforts to reduce fungicide inputs.
By sowing varieties with stronger disease resistance later in the autumn, there is scope to reduce the risk of a damaging septoria epidemic and enable the use of lower fungicide inputs.
The same study also examined other ways to tailor strategies to reduce disease pressure and fungicide use.
So, to sum up, using varietal resistance with other integrated pest management (IPM) approaches, such as monitoring, forecasting, and agronomic practices, will help growers protect crops.
It will also help tillage farmers reduce fungicide resistance risks.
