One of the key points coming out of the recent Teagasc Crops Open Day is the fact that ramularia can severely impact barley yields.
Moreover, the disease remains outside the scope of the current certified trials processes, used to recommend new cereal varieties.
In other words, there is no specific ranking for the disease, linked to the specific barley varieties.
This was a matter discussed by Teagasc’s Deirdre Doyle on a recent Tillage Edge podcast.
“The focus at the moment is building fungicide programmes that maximise protection against ramularia,” she explained.
“Spray timings are crucial in this regard. The right products must also be used to help against the disease.
“However, we are also looking at determining the amount of ramularia that is present on seed. Teagasc has also taken a similar approach, where net blotch is concerned.”
Ramularia threat
According to Doyle, there are two main timings that must be met when it comes to confronting the threat posed by ramularia in spring barley crops. One of these is the tillering stage.
“Spraying with a fungicide at this stage protects all the new tillers coming through. If the plant loses tillers, then yield losses will follow automatically,” she continued.
“The second fungicide timing is when the awns are starting to emerge. This is very important from a ramularia perspective.
“Trials have confirmed the benefits of including Folpet at this specific growth stage.”
Teagasc trials have confirmed that fungicide applications at tillering can deliver a yield response of 0.8t/ha on spring barley crops.
In addition, applications at around growth stage 40 can deliver a yield benefit of a similar magnitude.
Symptoms
Ramularia is a disease that attacks barley crops late in the season; yield loss is directly proportional to the loss in photosynthetic area.
As is the case with many plant diseases, stressed crops are more likely to show symptoms. However, once symptoms develop on the upper leaves, post-flowering, treatment is not effective.
It has also been shown that agronomic practices will have an impact on the prevalence of ramularia.
The bottom line here is that climatic conditions and various tank mixes can have an impact on stress levels.
Growers must also provide adequate nutrition to minimise the stress within a crop.
And where fungicide use is concerned, the primary objective is to build a programme that will protect the crop. Both tillers and the upper canopy must be protected.