Over the last couple of years, we’ve seen increases nationally in the Winter barley and Spring Barley acreages. This has replaced Wheat where Blackgrass has become a difficult weed to control with conventional chemistry. Winter Barley is a more competitive crop compared to Wheat, so has the effect of reducing the blackgrass population, while spring cropping gives us more opportunities over the winter to control blackgrass in the stubble or provides the opportunity to drill cover crops.
With poor disease resistance in the main barley varieties, higher fungicide use has been necessary to improve yields over recent years.
The main diseases of barley are rhychosporium, net blotch and ramularia.
Even though SDHI and triazole chemistry are still giving good levels of control of rhychosporium, we have seen a reduction of sensitivity to SDHI chemistry to net blotch. At field level we are still seeing good control, but careful use of both actives is important for future levels of disease control as part of a resistance management strategy.
Cyprodinil can be very useful addition to the armoury especially for its activity on net blotch, when trying to mix and match actives through the programme.
Adding Prothioconazole into the programme would be preferable where curative action is required, particularly if rhychosporium is present.
Multi-site chemistry is a very important tool to slow down resistance development, consider using at all timings but target a CTL at T2 because of its greater activity against ramularia. Further trial work is being carried out using folpet in the light of the CTL departure from the market post 2020. We also understand that the new triazole from BASF may have some activity against ramularia.
If you have any questions about fungicides and good crop protection practice, call our team today on 01243 755610