Early Disease Assessments – Winter Wheat Variety Trials

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Our winter wheat variety plots are already providing useful information about early disease levels. All varieties at our Dorset (drilled 03/10/18) and Wiltshire (drilled 23/10/18) sites had a moderate to high level of mildew present, the Dorset site compared to the Wiltshire site had approximately 10-15% more incidence of mildew on all leaf layers. Our Dorset site is currently at GS24 with the Wilshire site being slightly behind. Both sites have lacked a hard and prolonged frost which will have helped proliferate disease.

Septoria and brown rust varied across variety, however a general trend of the thicker more tillered crops tended to have a higher incidence of Septoria. KWS Extase showing increased levels of disease while KWS Lili proved to be the cleaner variety across both sites. The occasional brown rust pustule was spotted on susceptible varieties such as Crusoe.

What are the consequences for spring 2019 and should I be worried now?

Currently concern over disease in winter wheat should be low, it certainly doesn’t suggest we should be getting the sprayer out of the shed ready to spray our first fungicide. The season could go two ways, if we have some good cold weather which will bring with it a hard frost or two before the spring most of the disease will not survive and will be a mere memory come spring. However, if the weather continues to be mild with the occasional rain shower these diseases could well get the better of us. Therefore, the advice would be to assess the situation in the spring. If disease such as mildew is still present, then a curative fungicide such as fenpropimorph should be applied at the T0 (GS30-31) timing without delay. If the crop is showing Septoria, the use of a multi-site such as CTL at T0 will put us in good stead for the spring. If in the worse-case scenario there is disease present and no T0 was applied, you start the season on the back-foot. With very few registered curative products available in the marketplace, this puts the emphasis on using a T0 to ensure the season starts with the best possible chance for a high-yielding crop.