Wheat growers should focus on 10 varieties for this autumn’s drilling which could save them £40/ha in fungicide costs, and cut the risk of big yield losses in a high-disease season.
Improved resistance to wheat’s biggest disease threat, septoria, means growers can choose to grow these varieties, such as Siskin, Graham and Sundance, which can save on fungicide spray costs compared with the likes of Santiago, Diego and Barrel.
Bill Clark, fungicide expert at crop consultant Niab, said growing these varieties should allow growers to use only one SDHI and moderate rates of azoles, compared with two SDHIs and higher azole rates for disease-susceptible varieties.
“Growers can save about £40/ha on fungicide costs by changing varieties, and also reduce risks in a high-disease year,” he told Farmers Weekly at the 2018 Cereals event, held at Chrishall Grange in Cambridgeshire.
Mr Clark said growers could make quite a saving in a high-disease year by growing Graham with a fungicide cost of £98/ha, compared with Santiago at £135/ha, while in a low-disease year Graham would have a fungicide cost of £63/ha compared with Santiago at £110/ha.
He list the top 10 varieties from the AHDB Recommended List with good disease resistance as Dunston, Zyatt, Moulton, Motown, Sundance, Illustrious, Graham, Freiston, Crispin and Siskin.
These all show good resistance to septoria and so low yield responses to fungicide regimes, which may be as little as 1.41t/ha for Dunston compared with untreated crops.
These varieties should only need a reduced fungicide spray programme where a T0 is usually not required, a T1 is of a moderate-dose azole plus a protectant fungicide such as chlorothalonil, a T2 of a moderate rate of azole-SDHI plus a protectant and a T3 of a moderate-dose azole.
There is a moderately disease-resistant group of varieties, including those – such as Revelation, Skyfall, Costello, Gleam, Elicit and Bennington – that show a moderate response to fungicides of between 1.82-2.02t/ha.
The disease-susceptible group of varieties would include Santiago, Reflection, Cordiale, Leeds, Barrel, Lili and Diego, where the fungicide response is up to 3.77t/ha as in the case of Santiago.
These would have a full fungicide programme of a T0 consisting of an azole plus protectant, a T1 of a high-dose azole-SDHI plus protectant, a T2 of a high-dose azole/SDHI plus protectant, and a T3 of a high-dose azole.