Tillage advice: Off-colour barley, ramularia control and the new strain of potato blight
Teagasc Crops Specialist, Shay Phelan shares key advice for spring cereals, fungicide control programmes and EU43 – a new strain of potato blight identified in Ireland.
Spring cereals
Late April sown spring barley crops are at GS 37-39. After a good start, spring barley has hit a bump in the road in the last week. Many crops are off colour as compaction issues start to show. Other issues reported are BYDV and leaf scorch from herbicide and fungicide application. Disease levels are low expect for Planet, where net blotch remains challenging. Attention will turn to the awn emergence fungicide where Ramularia will be the target for all varieties.
Soil compaction is a big issue in many crops. While the soil surface was dry and fields were fit to roll post sowing, there was an underlying dampness that has led to some compaction issues.
The symptoms are usually yellowing of the crop as a result of restricted root growth and reduced nutrient uptake. It is important that the crop receives its major and micro nutrient requirements, but excess nitrogen or additions of micro nutrients will not alleviate the crop stress. Remedial action will come post-harvest.
Spring wheat and oats are growing well at the moment. Most crops have received PGRs at this stage. Disease levels are generally low, although yellow rust is visible in some spring wheat crops. Mildew levels are generally low, but growers need to keep an eye on it over the coming weeks.
Ramularia
Ramularia in winter barley is now starting to show up, especially where there is bad BYDV. Plants that were affected by BYDV are showing more noticeable signs of Ramularia on awns and flag leaves. Previously, we have seen yield differences of anything up to 3.5-4.0t/ha, depending on the level of BYDV in the crop.
While we don’t expect the same level of yield reduction in spring barley, growers should still be aware that crops may also be affected given the level of BYDV in spring crops (picture above).
Folpet in the form of Arizona, Mirror etc. plus an Azole mix, e.g. MacFare Xpro, Balaya + Imperis, should give the best control of Ramularia and other diseases, but these mixes must be applied at the awns peeping stage and don’t wait until the heads are fully emerged.
Winter wheat
Most October crops are now at the end of flowering and have received their head fungicide. However, November drilled crops are in mid flowering at the moment and the final fungicide is now due. Options are Prosaro/Jade at 1.0L/ha.
Figure 1: Winter wheat flowering
Potatoes
While most farmers are not interested in growing potatoes commercially, many grow a few drills of potatoes for the house or family. In 2023, Teagasc identified a strain of blight which is sweeping across Europe at the moment called EU43. This strain is very aggressive and is resistant to certain fungicides e.g. Revus. While commercial growers are using a combination of fungicides to control this and other strains, most hobby growers generally use one fungicide throughout the season.
Figure 2: Blight strain EU43 has been identified in Ireland
However, we are already hearing of blight in these crops and, for most, there is no economic control options. For most of the hobby growers, the responsible approach is to remove the affected leaves where possible and put them in the bin in an effort to remove the source of infection. Otherwise these crops should be destroyed, especially where they are located near commercial crops, as they will spread the infection.
Also read: 'Off colour' spring barley causing concern for growers
Tillage Edge podcast
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.
This week, Michael is joined by Ciaran Collins, Teagasc Crops Specialist, and Eoin Lyons, Teagasc Tillage Advisor, to discuss the critical agronomy actions needed over the next couple of weeks.
Listen in below: