Written by Corteva’s Field Technical Manager, Craig Chisholm
There will be no one-size-fits-all approach to T1 and T2 fungicide applications in 2024. The seemingly never-ending rain has seen to that.
Instead, we expect to see wheat growers across the UK and Ireland to make their product and rate choices on a field-by-field basis depending on their individual circumstances.
Septoria is not hard to find in well-established crops, even in varieties with well-proven resistance to disease such as Extase.
So, just like last year, we’re expecting a high-pressure season, which I appreciate is not the news growers need as they face a mounting list of spring fieldwork with few gaps in the weather to get machines moving.
Opportunities for T0 applications have been few and far between so the reality is that many will not happen at all, and our field teams are reporting a huge variation in crop growth stages by geographical region.
The question we are getting is what these conditions mean for fungicide programmes; where should you deploy your best material and how should it work in combination with other chemistry?
The unique mode of action offered by Inatreq™ active – the only quinone inside inhibitor (QII) available to UK and Ireland growers – should be a part of every fungicide programme to tackle septoria while also maintaining the efficacy of other actives.
Univoq™, which contains Inatreq in coformulation with prothioconazole, has proven itself to be the best material on the market for septoria control, used most often at the T2 timing.
The logic of saving your most effective product for T2 application is obvious when flag leaf protection and yield are key objectives, but 2024 might bring about a change of thinking as to its position.
Wet conditions have exacerbated background levels of septoria in crops and users need to consider their choice of product and rate used at T1. Where curative activity is needed, or conditions mean timing has been compromised, Univoq provides the best solution to getting on top of your disease control ahead of T2. When used at T1 the persistent protection offered by Univoq will ensure septoria does not creep in if the T2 application gets delayed.
We have data to show that this is an effective strategy. In the wet early season of 2023 there was a response at T1 all the way up to 1.4l/ha, but rates around 1.2l/ha will be more than justified on all but the most resistant varieties.
Our advice is to consider 1.2l/ha or higher if there is a risk of an extended interval to T2.
As well as being extremely effective against septoria, Univoq will provide sufficient efficacy to control yellow rust in the vast majority of varieties. Applications to those varieties which are highly susceptible to yellow rust, or where the rust is already well established, can be further strengthened with the inclusion of a strobilurin or tebuconazole.
However, Univoq’s strongest position in the programme remains in the T2 slot, and where growers feel confident to save their application until later in the season, they will see the same benefits demonstrated in the past three years of use on farm where Univoq has provided outstanding septoria control and a significant yield benefit in the process.
Corteva technical hotline:
Tel: 0800 689 8899
E-mail: ukhotline@corteva.com