Slightly warmer and wetter conditions have maintained disease risk and growers are being warned not to skimp on T0 wheat fungicides and compromise early season disease control.
Crops are at, or approaching, the optimum T0 timing for Sussex-based Procam adviser and Crop Watch contributor Richard Harding and he is keeping his earliest fungicide spray robust.
“Fungicide is not the input to put at risk if yield is to be protected. Septoria and mildew are still evident in many varieties,” he says.
Mr Harding’s choice of products will contain actives such tebuconazole, chlorothalonil, prochloraz and a mildewicide where needed, but with the main aim of clearing out stem-based diseases.
Prime Agriculture’s Marion Self has managed to save some fungicide costs by recommending fewer T0 fungicide sprays than predicted after crops came through winter looking “dirty”.
However, she is now seeing plenty of septoria that will be encouraged by the current unsettled weather and yellow rust is making a comeback in some varieties across her Suffolk area.
“Well timed T0 and T1 applications will be important to protect the emerging leaves and prevent these diseases moving up the canopy.
“Septoria is the most important disease to manage, but at these earlier timings don’t forget to addresss other issues such as mildew, eyespot and possibly take-all,” adds Ms Self.
In the west of the country, Herefordshire-based adviser Antony Wade has seen unsettled and blustery conditions limiting spray opportunities so many of his T0s are yet to be applied.
However, this isn’t too much of a concern as the prevailing cool conditions will see the emergence of final leaf 3 – the timing for the T1 fungicide – not later than the St Georges Day “rule of thumb” on 23 April.
With many of his wheats with the T0 target of final leaf 4 just 50% emerged, it means that the gap between the first two sprays should be nice and tight to maintain disease protection.
He also reminds reminds growers that of the importance of timing fungicide sprays to target the correct leaf layer and ensure that fungicides are applied in a protectant situation.
“It is interesting in recent press coverage associated with spray timings that pictures of split stems are used to illustrate this [correct timing].
“In my opinion, it is impossible to accurately assess leaf layer emergence on split stems. So the fiddly occupation of rolling back leaves is the order of the day for me, explains Mr Wade.