Most crops remain clean but disease still threatens

Still good crop potential: Good growth has resulted in many very heavy crops and a drier forecast for the week ahead is very welcome, especially for winter barley. Most crops have remained quite clean, but recent heavy showers towards the south of the country have increased the pressure from rhyncho and septoria. A dry forecast will also help against ear blight, but it will not remove all the risk.

If the weather dries up, rusts and mildew may become more prominent. Dense canopies will help mildew and make control more difficult.

Winter wheat: Final sprays will be going onto winter wheat now, as crops move into flowering and the interval since T2 is stretching. Final sprays will target ear blight, but septoria and rust (and mildew in places) are still major threats. If the interval since T2 is stretched beyond 24 days you will need more fire power activity. Triazoles are limited against septoria so robust rates are essential, even with double actives.

Where two SDHI products were used already, the final spray should be based on triazoles. Some will opt to add a strobilurin like Modem or Amistar to help deliver the crop’s potential. A contact fungicide (chlorothalonil or Phoenix) should also be considered where septoria has moved up the crop. Make sure you do not exceed the label rates of chlorothalonil if you have used it two or three times previously.

Triazole mixtures for T3 include Prosaro, Gleam and Magnello. If mildew is present add a morpholine or use Cello instead of Prosaro. Where septoria is a definite problem, Gleam is the preferred product. Robust to full rates are essential for ear blight control capability. Consider adding a moderate rate of strobilurin like Modem or Amistar Opti – this would also help against rust and provide stress protection.

Check crops for aphids before spraying. Some crops have aphids on the underside of leaves, but this may not warrant treatment now. Only use systemic insecticides like dimethoate or Aphox on the head. Avoid spraying when bees are active.

Spring barley: Final sprays are being applied as ears begin to emerge, while some early crops are flowering. Rhyncho is the major target, but you must also be covered against net blotch, brown rust and mildew. Final sprays can be Bontima, Siltra, Ceriax, Treoris plus a triazole or Fandango.

Add chlorothalonil or Phoenix to all final sprays to help prevent ramularia. Chlorothalonil is included in some products like Treoris and Amistar Opti. Alternatively, Proline or Opus, plus strobilurins and Bravo, can be used as the final spray. A morpholine might also be needed if mildew or brown rust are active. Check for aphids before the final spray.

Crows: Winter barley has moved quickly through grain fill to the point where crows cause damage. While rain, frequent showers and silage harvesting may help keep pressure down, it is essential to prevent initial damage. Concentrate on high-risk areas: along by fences, under wires, beside bare patches, etc. Put up protective items such as scarecrows, tape, thread, bangers, balloons, kites, etc. Maybe a bit of lead too.