As winter barley enters a rapid phase of growth, April stands out as the most critical month for agronomic decision-making. According to Teagasc, many Irish farmers are still falling short of their potential, with a five-year average yield of 8.5 t/ha, despite newer high-performing varieties on the market. To close this gap, timely and strategic action is essential — particularly around nitrogen management, disease control, and plant growth regulation.
Nitrogen Management: Split and Time It Right
In Index 1 soils, the recommended total N application is 180 kg/ha. While some growers may consider increasing this total, barley is inefficient at utilizing late-applied nitrogen, especially after the flag leaf emerges (GS 37-39). Therefore, it is crucial to complete the main nitrogen split by GS 32. For those opting for a third split, it should be timed well in advance of flag leaf development to maximize uptake and minimize waste.
Additionally, manganese (Mn) deficiency is again being reported in 2025, especially on light or alkaline soils. Growers are advised to monitor crops closely for symptoms (e.g., interveinal chlorosis, poor tillering) and treat early to avoid irreversible yield losses.
Fungicide Programmes: Tailor to Variety and Pressure
Teagasc trials continue to support a three-spray fungicide programme, particularly in moderate to high disease pressure years. However, many newer two-row barley varieties offer improved resistance to Rhynchosporium, net blotch, and mildew, allowing some flexibility. Where disease levels are low, a two-spray system may be sufficient:
- First spray (GS 30/31):
- Options: Siltra 0.6 L/ha, Elatus Era 0.8 L/ha, or Proline 0.4 L/ha with SDHI (e.g., MacFare Xpro 0.8 L/ha)
- Second spray (GS 39/49):
- Add Folpet 1.5 L/ha for Ramularia control
- Consider Navura + Comet where appropriate
Disease levels vary significantly across regions, so field scouting remains essential in tailoring input strategies.
Plant Growth Regulators (PGRs): Stay Ahead of Lodging Risk
To manage lodging risk and improve harvestability, PGRs should be applied between GS 32–37 for two-row varieties:
- Terpal: 1.2–1.5 L/ha
- Cerone: 0.5–0.7 L/ha
- Meddax Max: 0.3–0.5 g/ha
For six-row varieties or crops on highly fertile sites, Teagasc recommends a two-stage approach:
- GS 30/31: Moddus 0.2 L/ha + CCC 1.0 L/ha
- Follow with standard PGR at GS 32–37
However, weather conditions must be monitored closely. Frost can reduce PGR efficacy and increase risk of crop scorch, particularly if large diurnal temperature swings are expected. The current forecast suggests cooler nights will persist until late April, with rain expected the following weekend — a key consideration for scheduling inputs.
For winter barley growers, April is the tipping point between average and exceptional yields. With so many decisions — from nitrogen splitting to fungicide and PGR timing — compressed into this short window, attention to detail is more important than ever. Growers who align their agronomy with crop development, disease pressure, and weather patterns will be in the best position to achieve premium yields and grain quality in 2025.
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