Ramularia fungicide toolbox
Like with Septoria in wheat, the Ramularia fungicide toolbox initially covered three groups of chemistry: SDHIs, DMIs and multi-site fungicides.
However, with the sudden and dramatic loss of SDHI chemistry to effectively control Ramularia, the toolbox is now limited to DMIs and multi-sites only.
In 2016/2017 it was already reported that Ramularia was difficult to control. A year later, in 2017, research undertaken by Plant and Food Research detected Ramularia isolates with reduced sensitivity to SDHIs in Canterbury and South Otago.
A “perfect storm” of a wet 2018 barley growing season and the resulting high disease pressure fed Ramularia’s aggressive ability to mutate. Not only were high yield losses reported, but the efficacy of SDHIs were dramatically reduced further.
According to FAR’s Autumn Round Up 2020, Plant & Food Research identified three SdhC mutations that impacted on the performance of SDHIs against Ramularia in barley. In 2019, microplate assays found that 100 percent of the Ramularia isolates collected in the 2018–19 season were insensitive to this chemistry. It only took three seasons to render SDHIs ineffective.
With SDHI and strobilurin chemistry lost, DMIs (DeMethylation Inhibitors) such as BOLIDE® are key to control Ramularia. To ensure they keep providing effective control, they need to be protected by multi-sites.
Multi-site fungicides such as PHOENIX® Fungicide (PHOENIX) are critical to control and manage Ramularia. PHOENIX (folpet) affects several different metabolic sites within the pathogen and is protectant in action. Folpet has no known resistance and remains at a very low risk of resistance developing in cereal pathogens.
Break the resistance cycle with PHOENIX and BOLIDE
Win the fight against key diseases by combining PHOENIX and BOLIDE, the ultimate duo for resistance management.
Ramularia can cause extensive damage to the upper leaves of spring and autumn barley once crops have finished flowering, resulting in reduced crop quality and yield.