Varied drilling dates could increase disease risks

A mixed bag of winter wheat drilling dates this season could add extra pressure to regional disease risks, say agronomists.

Drilling dates have varied widely – from later in the east where persistent drought meant some crops weren’t planted until November, to much earlier in north and west England where good soil moisture saw drilling start in the first half of September.

Come spring, this could create a double whammy as the legacy of these drilling dates combines with the usual disease risks experienced in these regions, suggests Syngenta regional technical manager Joe Bagshaw.

“Early drilling increases risks from the key wet weather disease Septoria tritici – and many earlier-drilled crops were in wetter regions, such as the north and west, where pressure from septoria tritici is already traditionally high.

“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.”

Spring weather will also affect how diseases develop. But the impact of drilling date should not ignoreed. A T1 fungicide – typically applied in April to protect the first of the top three yield-building leaves – could be pivotal for keeping diseases at bay.

Factors to consider when planning an effective T1 strategy include strong activity against rust, good preventative activity against septoria, and long-lasting protection. An appropriate dose of the SDHI fungicide Elatus Era at T1 can meet these criteria.

“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.”