Be alert for early rust attacks

“With a high percentage of varieties planted this season having some degree of susceptibility to yellow or brown rust, or even both, it’s vital that growers are on their guard,” explains Melanie Wardle, Syngenta campaign manager for cereals.

 “Admittedly, yellow and brown rust can be difficult to tell apart during the early parts of the season. The monitoring initiative has been set up to provide an early warning for both. What is most concerning is that infections are so widespread so early in the season.”

 So far Mrs Wardle says rust has been reported as widely as Norfolk, Suffolk, Cambridgeshire and Essex in the East; Herefordshire in the West; Kent, Dorset and Hampshire in the South; and Yorkshire in the North. It has also been found in wheat in Leicestershire, Bedfordshire Oxfordshire and Warwickshire, she notes.

 “Where rust levels look likely to threaten yield it will be important to not only treat crops promptly but also ensure that key fungicides used in programmes provide sufficient rust activity.

 “For the early spray timing at T0, normally in March, we advocate use of the combined fungicide Cherokee. That’s because its cyproconazole component not only provides curative but also protective activity against rust infection. Its chlorothalonil ingredient brings added protection against Septoria tritici.

 “Later in the season, particularly for flag leaf protection at T2, with many growers likely to be considering a new generation SDHI fungicide this season, here too it will be important to check that your SDHI provides sufficient rust protection. The new generation treatment Seguris, for example, not only shows exceptional rust control but outstanding control of Septoria tritici,” she adds.

 At the T1 spray timing, Mrs Wardle says using Amistar or Amistar Opti, for example in second wheat for take-all activity, will also provide good activity on rust.

 Where rust levels look threatening before the usual T0 spray timing in March, growers may need to consider treating even earlier with an additional spray timing, Mrs Wardle adds.