Early field inspections are showing crops to be holding their own despite having been sat in waterlogged, anaerobic soils for some time. The above average temperatures appear to have allowed roots to develop and scavenge for nutrients and generally the root systems are much better than what was feared.
The focus now turns to the fields, where grass-weed herbicides have not been applied. In many fields grass-weeds have also coped well with the wet conditions, and where we have strong well-tillered black-grass, I fear for acceptable levels of control now, and unfortunately in fields with established highly-resistant black-grass, the next application is likely to be glyphosate and start again with a spring crop.
Going forward in these fields, spring cropping proceeded by the correct cover crop is likely to be the best option.
For crops where the herbicide programme has worked well, disease is the next big concern. Septoria tritici is very apparent on winter wheat, even on the more resistant varieties.
This is not unusual at this time of year, and it will be spring weather conditions which will determine whether it will turn into an epidemic like it did in the warm wet spring of 2014, or whether it will not materialise as happened with the cool dry spring we experienced last year.
The problem we have is we don’t posses hindsight glasses or a crystal ball, and unlike 10 years ago when we had reliable triazoles which could get the disease back in check if it took off, we now have no reliable means of eradicating the disease with our ever-diminishing chemistry set, so it is vital we stay ahead by adopting a protectant or preventative spray programme.
Septoria has developed since the days when we could rely on a blockbuster flag leaf fungicide to get us out of trouble and it’s important we develop too by front-loading our programmes with more emphasis on T0 and T1. Chemistry choice is also key and SDHI fungicides must now be used at T1 as well as flag leaf.
Cutting back early in the programme is now no longer an option, as if we allow septoria tritici to get established, we can no longer stop it with synthetic chemistry.
The choice of chemistry is also going to be key. While SDHI chemistry is still working reasonably well, we need to both protect the chemistry and get the most out of it. It is now an essential part of any T1 programme in order to make the most of its good septoria protection as well as at the traditional flag leaf timing.
With septoria tritici ever evolving, its vital we protect our single site fungicides with products providing multisite activity such as chlorothalonil or folpet. Multisites are again absolutely essential at T0 and T1.
Triazoles still have a big role to play, and at high rates, both epoxiconazole and prothioconazole can provide useful protection activity against septoria tritici. Eradicant activity now, however, is very limited; hence timing is of paramount importance.
With plenty of varieties already displaying rust symptoms, strobilurins could also have a big role to play this season. Not only can they provide excellent rust activity, they also offer physiological benefits, which means if we have a cool dry season where disease doesn’t really develop, you will still expect to see a financially viable yield response from the extra physiological benefits.
Mildew is also prevalent in many crops, and the wet winter could also encourage eyespot and these diseases should also be considered when formulating the fungicide programme.
In order to fulfil crop potential, and maximise growers’ margins this season, I certainly will be looking to front-load fungicide programmes using combinations of SDHI, triazole and strobilurins backed up with multisite protection.