Tillage Update 5th May 2022
Shay Phelan, Teagasc Tillage Crops Specialist has an update on crops of winter barley and winter wheat and spring barley. He discusses applying the final fungicide to winter barley and the final nitrogen split on winter wheat. He advises on fertiliser, weed and disease control in spring barley
Winter Barley
Most crops have 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 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.
Picture 1. Awns peeping is the ideal timing for the final fungicide
The video below shows the ideal timing for the final fungicide on barley
Winter Wheat
Most crops will have had their leaf 3 fungicide application applied in the last week which was applied in ideal conditions and so should ensure that crops remain clean up to the flag leaf stage. The next task for winter wheat is to apply the final split of nitrogen typically 25% of the total. With grain prices at record levels many growers will assume that it is still economic to apply the full recommended rates of nitrogen however the economics will also depend on the cost of the nitrogen when it was purchased. Last year the ratio of the price of a kg of grain relative to the cost of a kg of nitrogen was 6:1, this year it ranges up to 12:1, therefore it takes more grain to pay for the nitrogen. Teagasc published some BER tables showing the rates nitrogen needed to be reduced by depending on the cost of nitrogen and the price of grain at current prices the maximum recommended nitrogen rate should be reduced by approximately 27 kg/ha.
Spring Barley
Fertiliser
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
BYDV risk is higher this year especially with April sown crops. It is important to walk crops and search for aphids and 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 2021 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. Check wild oat products table for further information on rates and tank mix restrictions.
Disease control
Target fungicide application at mid/late tillering. 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. Variety disease rating, early sown versus late sown, Rhyncho in neighbouring winter barley, weather, shoot count – high or low, or resistance issues.
Find out more information and advice from the Teagasc Crops team here. The Teagasc Crops Specialists issue an article on a topic of interest to tillage farmers every Thursday on Teagasc Daily. Find your local Teagasc office here