This season’s mixed bag of winter wheat drilling dates could add extra pressure to the UK’s normal regional disease risks in 2023.
That is the message from Syngenta regional technical manager, Joe Bagshaw.
He says drilling dates have varied widely this season – from very early in the North and West where soil moisture levels were sufficient for drilling to start in the first half of September; to much later in Eastern regions where the summer drought persisted for longer and crops were often not planted until November.
Come spring, this could create a ‘double whammy’ effect as the legacy of these drilling dates combines with the usual disease risks experienced in these regions, he suggests.
“We know that early drilling increases risks from the key wet weather disease, Septoria tritici,” says Mr Bagshaw. “And many of this season’s earlier-drilled crops were in wetter regions, such as the North and West, where the pressure from Septoria tritici is already traditionally high.
Smaller plants hit harder
Syngenta, “Similarly, we know when winter wheat is planted later, smaller plants tend to be hit harder by yellow rust. And this season’s later-drilled crops tend to be in the drier East of the country, which is traditionally a yellow rust-prone region.
Joe Bagshaw
“Clearly, the weather in spring will also affect how diseases develop, but these effects of drilling date should not be overlooked. The T1 fungicide, which is typically applied in April and which begins the process of protecting the first of the top three yield-building leaves, will be pivotal for keeping diseases at bay. Factors to consider when planning an effective T1 fungicide strategy will include strong activity against rust, good preventative activity against Septoria tritici, and long-lasting protection. An appropriate dose of the SDHI fungicide Elatus Era at T1 can meet these criteria,” he adds.
Where Septoria tritici is a concern, Mr Bagshaw says inclusion of a multi-site fungicide in the programme will also be important to manage resistant strains.
“Prevention is better than cure: it is generally much easier and more cost-effective to minimise disease establishing in the first place rather than trying to get on top of it once it’s built up. It will be important to remain vigilant and use the correct fungicide strategy.
“Winter cold snaps, such as those we had in December, will suppress yellow rust and other diseases, but will not remove the risk completely,” Mr Bagshaw concludes.
