Farmers should build their barley disease control programmes through an integrated pest management (IPM) system, rather than just relying on chemical control. That was the message from Teagasc tillage adviser Ciarán Hickey at Crops and Cover Crop Cultivations 2023.

He spoke to the attendees about how mitigating the risk of disease in barley can start long before a sprayer enters the field.

A crop rotation is vital to keep diseases at bay by reducing disease carryover via the soil, crop debris, and volunteers.

The use of another cereal crop can help to reduce barley-specific problems such as net blotch, while a non-cereal break crop is preferable in terms of reducing total disease levels in the environment.

Farmers should select barley varieties to reflect local disease pressures and their knowledge of field history in relation to disease.

A delayed sowing date is also a proven method of reducing the disease pressure, whether that be winter or spring barley. Fungicide timings were also discussed. When it comes to spring barley, a two-fungicide programme is recommended, the first at the tillering stage to help protect tillers as the number of ears/m2 is the main determining factor in barley yield.

The second fungicide can then be applied at the ‘paintbrush’ stage, as the awns are emerging. There is no benefit to delaying this second fungicide, and control may be reduced as most fungicides work with a preventative action, rather than curative action.

Deirdre Doyle, agronomy technologist at Teagasc, then focused on the management of ramularia in barley. While this is considered a late season disease, a 65% infection of leaf two can still lead to a yield loss of 1.5t/ha.

There are many different sources of this disease from which a crop may be infected. Seed can carry over the disease from previous crops.

Research has shown that between 2015 and 2017, just under 50% of winter barley seed contained ramularia collo-cygni, the fungus which causes ramularia leaf spot disease.

The results were even worse for spring barley, with the proportion of seed with the fungus ranging from 60% to 95%, depending on the year.

The disease can also be transmitted by crop debris, volunteers and grasses, while stressed crops are more prone to the disease. Fungicide choice and timing were once again reiterated. While not as effective as chlorothalonil was previously, folpet still provides good control once it is applied at the correct timing, just as the awns are emerging.