Tillage advice: Fungicide options for winter barley and wheat

Teagasc Tillage Specialist Shay Phelan outlines options for fungicide treatments in winter barley and wheat, along with weed and disease control options in this article.

Winter barley

There are reports of early-maturing varieties (e.g. Joyau) having awns emerged or will be emerged in the coming days, so now is the ideal time to apply the final fungicide to crops. Target the awns peeping stage (picture above) for the final application. Trials from Oak Park clearly show that waiting until GS 59, when heads are fully emerged, will lower yields by up to 0.4 t/ha.

Trials have also shown that 50% rates of an Azole SDHI/Strobilurin mix (e.g. Siltra, Elatus Era, Decoy + Priaxor) will be sufficient and mix these with a full rate of Folpet 1.5 L/ha for ramularia control.

Winter wheat

Most early-sown crops will have had their leaf 3 fungicide application due, which is the ideal timing for the first fungicide and so should ensure that crops remain clean up to the flag leaf stage. In the video below, Steven Kildea, Teagasc Oak Park, highlights the importance of targeting leaf 3 with the first fungicide.

The next task for winter wheat is to apply the final split of nitrogen - typically 25% of the total. With the recent fall in grain prices, how much nitrogen in total should be applied will depend on the price that the nitrogen was bought for. Those who bought before Christmas paid the highest prices and so applying more than 200-210kg/ha (160-165 units/ac) will probably struggle to be economic given the value of the extra grain versus the cost of that nitrogen.

Spring barley

It is now getting very late for drilling spring barley crops and growers should only continue to do so where there is the expectation of the crop covering its costs. Target a yield of about 6-7t/ha and cap you spend on inputs.

Complete all remaining N applications on spring barley crops. Continue to monitor crops for nutrient deficiencies. There are reports of manganese/magnesium deficiency symptoms in crops. Where symptoms are present, include a suitable product to help rectify the deficiency.

BYDV risk is higher this year,  especially with April-sown crops. It is important to walk crops and search for aphids. If aphids are present, a pyrethroid insecticide should be applied at the 3-4 leaf stage. 

Weed control

Weed control was difficult last year especially ALS resistant weeds like chickweed, poppy and corn marigold. These weeds should be targeted first and the mix should contain a non ALS partner that has activity on the target weeds. The lesson from 2022 was that large chickweed was very difficult to control, so there is no room to delay herbicide application once the first flush or weeds has appeared.

Table 1: Weed control options for ALS resistant weeds 

Apply Foxtrot or Axial Pro for wild oat and canary grass control. Best control will come from early application and should be included with the broad-leaf weed control, as coverage and subsequently control will be reduced if delayed.

Disease control

Target fungicide application at mid/late tillering in the early-sown crops (i.e. those sown in late February / early March). This can increase yield by as much as 0.3 t/ha over delayed application at GS 31/32 in high disease pressure situations. Use 50% rates of any of the fungicide mixes (e.g. Decoy/Comet, Macfare Expro, Siltra, Elatus Era etc.), which will give sufficient control. There is no benefit in adding Folpet at this stage.

For more inforation and advice from the Teagasc Tillage team, visit the Tillage Edge Podcast webpage. The Tillage Edge is Teagasc’s weekly podcast for tillage farmers. Presented by Michael Hennessy, the podcasts will cover the latest information, insights and opinion to improve your tillage farm performance.