Getting the best spring barley crop in a late season

There are some good, even emergences out there and the moist conditions mean that many of the first crops in have tillered and are actually ahead of the same time last year where seed went in at the start of a dry spell and then lay for weeks.

Of course, there are exceptions and crops that went into wetter than ideal conditions have struggled, and there seems to be a link with some of the poorer crops and rolling in wet conditions.

For the thicker crops with better potential then T1 fungicides are due and in a wet season such as we are having, preventing the ingress of rhynchosporium and other foliar diseases is probably worthwhile.

Farmers are hoping for good yields this year

Growth is likely to be very rapid this year which diminishes the benefits of a T1 fungicide. We know from SRUC research that in drier years, and for resistant varieties, it is possible to cut back or limit this spray, but the downside is that if disease does nip in to the gap before T2 then there is no way back. Thin crops that are not tillering and just shooting through growth stages are probably at less risk of disease and can make do with much lighter inputs at T1.

Moderating nitrogen inputs to the crop will be necessary in most scenarios. The rule of thumb is 2kg less per day after optimum drilling date. Optimum drilling dates obviously vary field to field but are usually mid-March to mid-April, so many crops were a month or more behind this season.

Ramularia – a new fungicide option

Ramularia leaf spot (RLS) is the real nut to crack with spring barley and has been increasingly tricky over recent years. It developed resistance to several major fungicide groups so control options were limited.

It grows inside the barley plant from infected seed, with visible symptoms often only appearing after flowering, and wet weather from emergence through to flower allows it to move more easily to the upper leaves.

Recent SRUC research confirms that it is the prevention of visible symptom development, rather than prevention of the hidden asymptomatic growth within the plants, that is important for management of this disease.

Experimental control methods targeted at delaying senescence could be a useful avenue for further investigation.

Fungicide options include prothioconazole, which still brings some useful activity despite resistance issues in ramularia. It can be applied up until the beginning of flowering. Mefentrifluconazole has better activity but the cut-off is GS45 for crops destined for malting so that timing is rather before what SRUC trials show to be optimal if that is your target market.

New for this season is pydiflumetofen in Miravis Plus, which is being sold in twin packs with prothioconazole (Era).

This new offer is steps ahead for efficacy in our trials. It is certainly an option for the higher yield potential crops in areas with the strongest history of ramularia.